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12-42, 8-26, 10-34, 9-30, 16-58 2005-08-31
Elizabeth pose la question :
here is a math question my niece gave me, grade 7

12-42, 8-26, 10-34, 9-30, 16-58

first day of school and this is what they give her no explanation

Harley Weston lui répond.
1,4,9,1,6,2,5,3,6,4,9,6,4,8,1 2005-08-30
Liz pose la question :
Find the next four numbers to the sequence 1,4,9,1,6,2,5,3,6,4,9,6,4,8,1,___,___,___,___.
Penny Nom lui répond.
cos x * cos 2x * cos 4x * cos 8x 2005-08-29
Leandro pose la question :

A = cos x * cos 2x * cos 4x * cos 8x

What's the value of log A at base 2?


Chris Fisher and Penny Nom lui répond.
The area of a lot 2005-08-29
Richard pose la question :
My wife and I are interested in buying property in Idaho but the owner can't give us a square footage of the lot. The dimensions are as follows:

121.0 on the left side
157.0 on the right side
135.0 on the bottom
162.0 on the top

The bottom right corner of the lot is a true right angle, the rest are not.

Penny Nom lui répond.
The length of a lot 2005-08-28
Billy pose la question :
If I have 3 acres and the front is 300 ft across how many feet would I go down the sides to equal 3 acres?
Penny Nom lui répond.
1_2_3_4_5_6_7_8_9 = 1: Fill in the blanks 2005-08-26
James pose la question :
Try to replace the blanks below with + or - to make the statement correct
1_2_3_4_5_6_7_8_9 = 1

Penny Nom lui répond.
Graphing a linear inequality 2005-08-26
Gina pose la question :
When graphing a linear inequality, how do you know if the inequality represents the area above the line?
Penny Nom lui répond.
y = log(x) + x. Solve for x. 2005-08-26
Alain pose la question :

I have the following equation:

y = ln(x) + x

How do I solve for x?


Penny Nom lui répond.
The area of a triangle 2005-08-26
Martha pose la question :
I have a triangle that with a base of 60' and the two sides of 37'. I know the formula for area is A=1/2 (b*h) but how do I find the height??
Penny Nom lui répond.
The area of a pentagon 2005-08-24
Susan pose la question :
I need to calculate the square footage of a regular pentagon (all angles are equal). Each side is 16 feet long.
Penny Nom lui répond.
Labour efficiency 2005-08-23
Rob pose la question :

The problem, on the surface, seems very simple and yet has created some controversy among a group of accountants. The problem itself has to do with labour efficiency rates and only involves two variables; standard working hours, and actual working hours. The difficulty lies in deriving an efficiency % from these two numbers.

Standard working hours or the targeted number of labour hours required to produce one widget, which I will represent as "s". Actual working hour or the actual number of labour hours require to produce one widget, which I will represent as "a". Labour efficiency I will represent with "E". The prevailing calculation with which I have a problem with is this:

s/a=E or if s=3000, and a=4000 then 3000/4000=75%

What bothers me about the calculation is that the standard hours get represented as a percentage of the actual hours and in my opinion changes the focus of the calculation from standard or target, where it should be, to the actual hours. I cannot define why, but this just seems inherently wrong to me.
The calculation that I use:

(1+((s-a)/s))=E or if s=3000, and a=4000 then (1+((3000-4000)/3000))=66.67%

My calculation is like a %change from standard calculation. However, there is something that also concerns me about my calculation.

If you substitute 100 for a and 50 for s, then you come to a quandary, because if you plug those numbers into the second equation the result is of course zero % efficient which doesn't sit right with me either. If you plug them into the first calculation you get 50% efficiency which doesn't really seem to work either, because you require 100% more hours to do the same work in this case. ???

Is the first calculation correct? Am I missing something altogether? Are both calculations off base?


Harley Weston lui répond.
The range of a function 2005-08-21
Kelsey pose la question :
What is the range of the function f(x) = 4x - 6 when the domain is {-3,-1,1,3,5}?
Penny Nom lui répond.
Fran goes to college 2005-08-21
Thomas pose la question :
Fran will begin attending longview college 1 year from now and will attend for the next 4 years. Her annual cost will be $14,000.00 which her parents have agreed to pay. Frans parents have saved enough money to meet Frans needs. How much must they invest in an account paying 10% interest compounded annually in order to receive $14,000.00 at the end of each of the next 4 years, having nothing left in the account at the end of that time?
Penny Nom lui répond.
Their sum equals their product 2005-08-21
Claudio pose la question :
Find a thousand natural numbers such that their sum equals their product.
Penny Nom lui répond.
3A/4 +1=(2A-1)/3 2005-08-21
Rachael pose la question :

I'm doing a practice test question and the answer I keep turning out is different from the answer on the answer sheet. I think I might be forgetting a step. The problem is:

3A/4 +1=(2A-1)/3

The answer is -16. If anyone could explain the steps to me to getting the answer I would be grateful. Whenever I do it I get something completely different.


Penny Nom lui répond.
The area of an octagon 2005-08-21
A student pose la question :
Hi I am a ninth grade student trying to figure the area of an octagon with sides of 4 feet and another one with sides of 5 feet
Penny Nom lui répond.
Can one place 15 integers around a circle... 2005-08-20
Hernan pose la question :
Can one place 15 integers around a circle so that the sum of every 4 consecutive numbers is equal either to 1 or 3?
Claude Tardif lui répond.
The radius of an arc 2005-08-19
Jared pose la question :
I need to be able to calculate the radius of an arc on an existing structure (Supports for Fifth Ave Dimensional Text). I have the overall length of this structure, but, the complication I believe lies in the fact that it is a curve mounted onto a flat section of wall on either side of a very mild curve, therefore, measuring the middle of the wall to the top of the arc does me little good...The reason I need this is to be able to replicate the above curve on a similar structure to be mounted below it...Also, because the client wants the structure mounted on the inside of the opening below the existing, the beginning and end point of the new structure would be lower than the existing, so, I do not believe that it is possible to exactly replicate the radius of the above curve?
Penny lui répond.
Which number is greater? 2005-08-18
Dante pose la question :
Which number is greater: 888....88 X 333...33 or 444.......44 x 666........67 (each of the numbers has 1989 digits)?
Claude Tardif lui répond.
Three days interest on one million dollars 2005-08-18
Teresa pose la question :
how much money is 3 days interest on one million dollars?
Penny Nom lui répond.
The volume of the earth in gallons 2005-08-18
Daniel pose la question :
I would like to know how to find the volume of the Earth in gallons.
Penny Nom lui répond.
Sample variance 2005-08-17
Rosalie pose la question :
To give an unbiased estimate of the population variance, the denominator of the sample variance should be (n-1) instead of n. I tried to convince myself by comparing the population variance and sample variance (with denominator n and n-1):
Penny Nom lui répond.
My fantasy football league 2005-08-16
Jim pose la question :
I have to make a schedule for my fantasy football league. There are 10 teams in the league and we play a 13 week season. The challenge is we want to play each team only once during the first 10 weeks. This way no team will play another team twice without having played each team at least once. Is this possible?
Penny Nom lui répond.
Hat size 2005-08-16
Keshia pose la question :
What formula would I use to find the measurement of a hat size? Ex. If the hat was 7 3/4", what formula would I use to get that measurement?
Penny Nom lui répond.
Is this percentage change or percentage increase? 2005-08-15
Betty pose la question :
When calculating a percentage, if the formula is A(new) - B(old)/A(new) Is this percentage change or percentage increase?
Penny Nom lui répond.
The diagonals of a hexagon 2005-08-15
Brittany pose la question :
are all of diagonals in a hexagon has same length
Penny Nom lui répond.
Jim is travelling from Toronto to Ottawa 2005-08-15
Eleanor pose la question :
Hi! I am looking for an easy way to solve this type of question: Jim is travelling from Toronto to Ottawa, a distance of 435 miles. He travels part of the way at a speed of 100 km/h and because of an accident, he uses a secondary road and travels at 70 km/h. If the trip took him 6.5 hours, how far did he travel on each of the two roads.
Penny Nom lui répond.
Is 360 Really the correct value? 2005-08-15
Jack pose la question :
Considering the circumference of a "Perfect Circle" with a Diameter of 1 meter would be something like 3.14 meters, why do we use the number 360 to represent the number of degrees within that circumference?

Would it not make more sense to express the degrees in reference to the relationship to the diameter as related to pi?

That is, let's just say our "Perfect Circle" has a circumference of 3.14 meters, therefore, what we now consider as due east would change from 90 Degrees to 78.5 Degrees.

Penny Nom lui répond.
Stock in a printing company 2005-08-12
Tracy pose la question :
Sam and Mary each owned one-half stock in a printing company. Sam sold 2/3 of his stock to Mary. What fractional part of the printing business does Mary now own?
Penny Nom lui répond.
Framing an arched wall 2005-08-12
Mike pose la question :
I'm framing a building wall with a curved (arcing) top section. The radius of the section is 74'6" with a height above finish floor of 16'0". The horizontal run of the arced section is 23' 1 1/2" with a low height above finish floor of 12'4". If I start with a 16' stud at the high end how long are the subsequent studs if they are on 16" centers? Short of laying this out on a tennis court how can I work out the lengths of the studs?
Penny Nom lui répond.
A triangular lot 2005-08-10
Elizabeth pose la question :
If a piece of property was 100 ft on the west, 133 ft on the east and 100 on the north, how many acres is this or what fraction of an acre is this property?
Penny Nom lui répond.
The Maclaurin series generated by f(x)=x^ cosx + 1 2005-08-10
Latto pose la question :
f(x)=x3·cosx + 1. but when I take the derivatives, I couldn't see a pattern. Can you help?
Penny Nom lui répond.
Proof by induction? 2005-08-10
Peter pose la question :

I am a lecturer and am having a problem with the following Proof by
Induction.

If

(N x N x N x N) + (4 x N x N x N) + (3 x N x N) + (N) = -4000

Prove that N is even!


Chris Fisher and Penny Nom lui répond.
The volume of soil needed to fill a planter 2005-08-10
Phil pose la question :
I need to calculate the volume of soil needed to fill a planter box that measures - 880mm W x 6080mm L x 900mm D.
Penny Nom lui répond.
Cubic feet 2005-08-10
Selene pose la question :
This is my math question I need to convert these inches to cubic feet 34"W x 34"H x 34"L
Penny Nom lui répond.
The number of four digit combinations 2005-08-09
Kevin pose la question :
My 12 year old has asked me how to figure out the number of four digit combinations possible using 0 thru 9 without repeating a number?
Penny lui répond.
how do i round up 9.6 to the nears ones 2005-08-09
Carlos pose la question :
how do i round up 9.6 to the nears ones
Penny Nom lui répond.
A two digit number 2005-08-09
Grace pose la question :
I am a 2 digit number. Both of my digits are even. My tens digit is 8 more than my ones digit. What number am I?
Penny Nom lui répond.
Constructing a fence 2005-08-09
Andres pose la question :
I was constructing my fence and was having some problems trying to do a perfect (or as close as possible) arch. If i know a section of a fence is for example 85 inches wide and I want a 4 inch rise from the top rail how do i figure out the radius?
Penny Nom lui répond.
At what rate is the circumference of the circle increasing? 2005-08-08
John pose la question :

A mathematics professor is knitting a sweater. The main part of the sweater is knit in a large spiral, ending up with a diameter of 30 inches. She knits at a constant rate of 6/7 square inches per minute.

1. At what rate is the circumference of the circle increasing when the diameter is 2 inches?

2. How long will it take her to finish this piece of the sweater?


Penny Nom lui répond.
A normal distribution problem 2005-08-08
Brad pose la question :
The life of a toy is normally distributed. Suppose 92.51% of the items lives exceeding 2,160 hours and 3.92% have lives exceeding 17,040 hours. Find the mean and the standard deviation.
Penny Nom lui répond.
Area of a lot 2005-08-07
John pose la question :
We hope this copy of our survey map will help you to determine the acreage of our land.
Harley Weston lui répond.
Converting rational numbers 2005-08-07
Joe pose la question :

I am helping my son with his converting rational
numbers in the form of A/B where A and B are integers and
B not equal to zero

I think I am doing this right but I am not sure so
below are the problems and our answers are beside
them, please let me know if these answerers are correct


Penny Nom lui répond.
A golf outing for 16 golfers 2005-08-05
Bob pose la question :
I have a golf outing fast approaching and I’m having a problem matching the golfers so that everyone plays a round of golf with every other golfer in the group.

My problem is this: I have 16 golfers playing 5 rounds of golf. I would like a different foursome for every round of golf, that is each round (5 total) an individual is playing with 3 other players he hasn’t played with as of yet. Can you crunch the numbers and get back to me?

The way I see it, we have 20 combinations (5 rounds x 4 golfers) with numbers 1 thru 16.

Chris Fisher lui répond.
What is the radius of this planet 2005-08-05
Kelly pose la question :
Assuming that a North-South line has been established, you set up two camps that are 67 miles apart. You now set up poles at each camp perpendicular to the ground. On a certain day at "noon" the pole at the South camp casts no shadow, while at the North camp a shadow is cast. The shadow makes an angle of 89 degrees with the horizontal. What is the radius, diameter, and circumference of this planet?
Chris Fisher lui répond.
Cubic yards of sand 2005-08-04
Beth pose la question :
I am trying to figure out how much sand I will need for ground cover under my children's playset. The area to cover is 30' x 30' and I want 4 inches of sand.
Penny Nom lui répond.
0.02 acres 2005-07-31
Negin pose la question :
know how much is 0.02 acres in square footage?
Penny Nom lui répond.
A perfect square that is equal to 1 acre 2005-07-31
Shannon pose la question :
If you have a perfect square that is equal to 1 acre, what is the length of the sides and how do you do it?
Penny Nom lui répond.
A television antenna sits on a roof. 2005-07-30
Liz pose la question :
A television antenna sits on a roof. Two 76-foot guy wires are positioned on opposite sides of the antenna. The angle of elevation each makes with the ground is 24 degrees. How far apart are the ends of the two guys wires?
Penny Nom lui répond.
A concrete slab 2005-07-29
Armand pose la question :
I am planning to pour a concrete slab over an existing slab in my garage
which is very uneven, with a depth variation from 2 1/2 inches to 5 1/2
inches from level. I'm afraid to over estimate concrete since it will be
wasted but worse, I'm afraid to underestimate. I've broken the slab down
into four sections with the following being the four dimensions, can you
tell me how much concrete I will need please, I would very much
appreciate your help.
1- 6ft/8in x 20ft x 4 1/2 in. thick
2- 16ft/10in. x 20ft x 3 1/2 in. thick
3- 6ft/6in. x 16in. x 5 1/2 in. thick
4- 6ft/6in. x 8ft. x 4in. thick

Penny Nom lui répond.
Speed on a bicycle 2005-07-27
Deborah pose la question :
We are trying to figure out how many miles per hour we rode in a bike race. If the distance was l5 miles and the time it took was was 55 minutes, what is the speed?
Penny Nom lui répond.
Cubic feet in a mobile home 2005-07-22
Jeanne pose la question :
my mobile home is 24 x 56. I'm trying to find out how many cubic feet this is. I'm going to set of some bug bombs and it says 1 can will cover 4000 cubic feet. I don't know how to figure my cubic feet. the ceilings are 8 ft high everywhere but the living and dining room. They are vaulted and approximately 10 feet at the peak. I just need an estimate.
Penny Nom lui répond.
Some geometry problems 2005-07-22
Sherry pose la question :
1. If Circle K has tangents RT and TY where R and Y are the points of tangency, then angle RKY and angle RTY are supplementary.

2. If one diagonal bisects a pair of opposite angles in a quadrilateral, then the quadrilateral is a kite.

Penny Nom lui répond.
A set of numbers whose sum is 1 2005-07-21
Santos pose la question :
Does there exist a set of numbers whose sum is 1, and the sum of whose squares is less than 0,01?
Paul Betts lui répond.
The period of sin(x) + cos(x) 2005-07-21
A student pose la question :
WHAT IS THE PERIOD OF SIN(X)+COS(X)?
Penny Nom lui répond.
Solve for x 2005-07-20
Ed pose la question :
(x-1)/3 - 1 = (x + 2)/2
Penny lui répond.
How many tiles do I need? 2005-07-20
Jeannette pose la question :
I am putting up backsplash tile in my kitchen and I need to know how many tiles I would need to use for about 45 square feet using 4x4 tiles.
Penny Nom lui répond.
Three prime numbers p,q and r, all greater than 3, form an arithmetic progression: 2005-07-18
Ladis pose la question :
Three prime numbers p,q and r, all greater than 3, form an arithmetic progression: p=p, q=p+d and r= p+2d. Prove that d is divisible by 6.
Chris Fisher lui répond.
The equation of an ellipse 2005-07-17
Allan pose la question :
I working on a problem that asks me to give the equation of an ellipse when only the location of the directrix and the length of the latus rectum are given. No other points on the ellipse are given. Again, the only "givens" are:

Length of latus rectum = 12
Location of directrix is x = 16

If I could determine the eccentricity, I could proceed from there by taking the ratio of the distance from a focus to the latus rectum point to the distance of the point from the directrix, but I lack the x coordinate of c. I've searched the text, and feel I've "missed something" somewhere! I note that the latus rectum segment is unique in one respect in that it is parallel to the directrix, where any other line segment on the ellipse to the focus would not be. Please indicate where I'm going wrong.

Chris Fisher lui répond.
The area of a lot 2005-07-17
John pose la question :
A plot of land has the following dimensions: 391 ft. x 757 ft. x 208 ft. x 788 ft. Q: How many acres is this?
Harley Weston lui répond.
10% of $50 2005-07-16
A student pose la question :
If I had $50 and 10% of it had to go to my mother, how much would I have left?
Penny Nom lui répond.
A percentage of the whole 2005-07-16
A student pose la question :
two people both own property and would like to combine their properties into one. the first person contributes 1 acre and the second person contributes 1.5 acres. of the whole, how much percent does the first person own?
Penny Nom lui répond.
A lighthouse is located on a small island,... 2005-07-14
Brittnee pose la question :
A lighthouse is located on a small island, 3 km away from the nearest point P on a straight shoreline, and its light makes four revolutions per minute. How fast is the beam of light moving along the shoreline when it is 1 km from P?
Penny Nom lui répond.
Cubic yards of topsoil 2005-07-12
Maggie pose la question :
How much topsoil in cubic yards i need to order to cover 7500sq. ft. 3 inches deep?
Penny Nom lui répond.
The value of n*tan*(180/n) tends to pi 2005-07-11
Daniel pose la question :
I am 14 and i have been given a piece of maths coursework whereby a farmer has to fence off a piece of land as large as possible using 1000m of fence. I already know that the formula for working out the area of any shape of a 1000m perimeter = 5002/ n*tan*(180/n), however, after some research I have found out that as the number of sides (n), tends to infinity, the n*tan*(180/n) tends to pi. Why is this?
Penny Nom lui répond.
A melting ice sphere 2005-07-09
A student pose la question :
A 2 meter diameter sphere of ice melts at 1.5 millimeters per minute. How many minutes will it take to fill up a hexagonal container measuring 1.5 meters on a side, and 0.8 meters deep?
Penny Nom lui répond.
The volume of a pool 2005-07-09
Douglas pose la question :
I have a pond that I need to treat with an anti algae solution which needs to applied based on the volume of water in the pond (in gallons).

The rough diameter of the surface of the pond = 25 ft
The depth of the pond = 8 ft
The pond shape is conical

How many gallons of water are in my pond?

Penny Nom lui répond.
What percent of 100,000 is 629.77? 2005-07-08
Someone pose la question :
What percent of 100,000 is 629.77?
Penny Nom lui répond.
Percent change 2005-07-01
Betty pose la question :
Can you tell me the difference between Percentage Change, Percentage Increase, Percentage Difference and please give an example of each, I am very visual.
Penny Nom lui répond.
The substitution method 2005-06-28
Addie pose la question :
how do i know where to began the substitution method? how do i solve y = x + 1 2x - y = 1
Penny Nom lui répond.
Seven digit numbers 2005-06-23
Ky pose la question :
How many number combinations are possible for a 7-digit number? How many people in a population can exist without having to exceed the seven digit combinations and having to revert to a 8 or 9 digit number?
Penny Nom lui répond.
Profit of more than 100% of cost 2005-06-22
sam pose la question :
I know I can work out what percentage profit I am making by : profit/cost x 100, and I can work out up to 99% profit (the way I currently calculate it is profit x 1.99) But how do I work out any amount over 100%, say for instance I have something that costs me $0.52 that I wish to sell for 250% profit?
Penny Nom lui répond.
An algebraic remainder 2005-06-22
Raymond pose la question :
Given that 4x3 - kx is divisible by 2x+1, find the remainder when the expression is divided by 4 - x2.
Penny Nom lui répond.
A geometric sequence 2005-06-21
A student pose la question :

The first three terms of a geometric series are 3(q+5), 3(q+3), (q+7) respectively.
Calulate the value of q.


Penny Nom lui répond.
Discriminant 2005-06-20
A student pose la question :
If a quadratic has real root, its discriminant b2-4ac>=0 Is there any similar condition or method by which you can find whether roots of a cubic equation are real or not?
Chris Fisher lui répond.
An octagonal gazebo 2005-06-19
Tucker pose la question :
I want to build a gazebo that is a regular octagon 15 feet across. How do I figure the length of each side?
Harley Weston lui répond.
An integer x when divided by 5 leaves the remainder 3. 2005-06-18
A teacher pose la question :
An integer x when divided by 5 leaves the remainder 3. Prove that when 4x is divided by 5, 2 is the remainder
Penny Nom lui répond.
Two tangents to a circle 2005-06-18
Tej pose la question :
The tangents drawn from points M and N of a circle having centre O intersect each other at point P. If angle MPN=60 degrees, NM=10, then find the radius of the circle and Area of quadrilateral OMPN.
Penny Nom lui répond.
p+1, p+2 y p+4 are prime 2005-06-18
Vincent pose la question :
Find all the values of p (where p is a natural number), for which the numbers p+1, p+2 y p+4 are prime.
Penny Nom lui répond.
In how many ways can 12 different fruits be distributed 2005-06-13
Sapta pose la question :
In how many ways can 12 different fruits be distributed among 3 boys so that each receives at least 1 fruit?
Claude Tardif lui répond.
20% profit 2005-06-12
Shawn pose la question :
If I know that I will be paid, say, $150.00, for labor, and I want to make 20% profit on what I pay for the labor, what is the calculation and factoring process?

I see it like this

(x*.2)+x = 150

but I don't know how to factor it out from there.

Penny Nom lui répond.
The sum of the digits of 2^100 2005-06-11
Richard pose la question :
The sum of the digits was calculated for the number 2100, then the sum of the digits was calculated for the resulting number and so on, until a single digit is left.
Penny Nom lui répond.
The size of a lot 2005-06-09
Bob pose la question :
Is it possible to determine the square footage and acreage of a residential lot that's straight on 3 sides, and triangular on the 4th side?

As shown in the crude sketch below, the two legs of the triangle at the back end of the lot are 61' and 62'.

Penny lui répond.
Digging a hole for a pool 2005-06-08
Debra pose la question :
I need to have dirt hauled away from my built in pool and the haulers are asking me how many yards of dirt there is. How would I figure that out? It is a 24 ft round pool and 3 inches of soil depth was dug out.
Penny lui répond.
An octagonal deck 2005-06-07
Scott pose la question :
I want to build a octagonal deck. The wood I am using are cut in 8 foot lenghts. What I want to know is if the sides of the octagonal are 8 feet, what is the diameter. Also what are the angles of each side?
Penny Nom lui répond.
How many digits? 2005-06-07
Floren pose la question :
The numbers 21989 and 51989 are written one after another. How many digits in all are there?
Claude Tardif lui répond.
Asymptotes 2005-06-06
Abraham pose la question :
What are the equations of all horizontal and vertical asymptotes for the curve y=x/(x(x2-4))(the answer is y=0, x=-2, x=2, but I want to know how to get that algebraically.And why isn't x=0 another asymptote?)
Leeanne Boehm lui répond.
The length of a whale 2005-06-04
Judy pose la question :
A whale's head is 72 inches long... its tail is as long as its head plus half the length of its body, and its body is half the entire length. Who long is the whale?
Penny Nom lui répond.
Primes 2005-06-04
Fede pose la question :
Prove that there is not a number prime p, for which the numbers p+5 and p+10 are prime too.
Penny Nom lui répond.
arccos(5/13) 2005-05-31
Kyle pose la question :
I would like to know how to evaluate the problem of: Arccos 5/13.
Penny Nom lui répond.
The numbers p and 8p^2 +1 are prime. 2005-05-30
Antonio pose la question :
The numbers p and 8p2 +1 are prime. Prove that the number 8p2+2p+1 is also a prime number.
Claude Tardif and Penny Nom lui répond.
The volume of a sphere. Why 4/3? 2005-05-30
Lauren pose la question :
You know when you find the volume of sphere? I know the formula is V= 4/3 pi r3 but why do they use 4/3?
Penny Nom lui répond.
Square feet and cubic feet 2005-05-30
Kim pose la question :
Is there a relationship between square feet and cubic feet?
Penny Nom lui répond.
5+5+5=550 2005-05-30
Bill pose la question :

5+5+5=550

This is a math equation that is not true. How can it be made to be true by using only one line?
Leeanne Boehm lui répond.

Which is larger, 31^11 or 17^14? 2005-05-29
Linda pose la question :
Which number is greater 3111 or 1714 (without using calculator).
Chris Fisher and Paul Betts lui répond.
The volume of a hopper 2005-05-28
Brian pose la question :
I would like to know the volume of this rectangular hopper. can you help
Penny Nom lui répond.
Cost price 2005-05-25
Sunitha pose la question :
What is (how to calculate) the cost price of a product which is marked-up by 15% and retailed at $25?
Penny Nom lui répond.
A parabolic mirror 2005-05-24
Nathan pose la question :
i am trying to find the equation for a mirror for a laser experiment. the mirror is parabolic but my question is how do you find the equation when you know only the focus and the diameter the mirror diameter is 520 mm and the focus is at 1024 mm. would you just use the measurements in the equation instead of "nice numbers" or what.
Penny Nom lui répond.
Logarithmic differentiation 2005-05-23
Richard pose la question :
I need to convince myself that I understand the process of differentiating y=xx.
The specific question is that if I have to take the logarithm of both sides of the equation how can differentiate the following?
y= {(x+2)(x+2)}/{(x+1)(x+1)} - {(x+1)(x+1)}/(xx),
I have an idea that the differential of this fairly complex function is itself ... am I right or wrong.

Penny Nom lui répond.
Cubic feet of concrete 2005-05-23
Robert pose la question :

REQUIRED CUBIC FEET OF CONCRETE TO POUR AN EXTENDED PAD

8 FEET X 8 FEET X 6 INCHES DEEP


Penny Nom lui répond.
50^99 and 99! 2005-05-23
Romel pose la question :
Which number is greater, 5099 or 99!
Claude Tardif lui répond.
A triangular lot 2005-05-21
Linda pose la question :
I am looking to purchase a piece of property, and I need some help trying to figure out the square footage of the land. I know that normally if I multiply the length and width I could get my answer. However, this piece of land is an odd shape and has 3 measurements. Can you please help me.
The measurements for this piece of land is:

97.8'
201.2'
139.7'

Penny Nom lui répond.
The area of an octagon 2005-05-21
Jeremy pose la question :
i need to find the area of an octagon with each side measuring 1 foot
Penny Nom lui répond.
Factoring 2005-05-20
Abraham pose la question :
Can you please explain to me how to factor completely the following problem:
(sqrt(x+1))-((x2+2x+1)( -7/4)).

Penny Nom lui répond.
A right triangle 2005-05-18
Bill pose la question :
If I know the base and the slanted side of a right triangle, how do I figure out the height?
Penny Nom lui répond.
The units digit 2005-05-18
Gerald pose la question :
Juan wrote the first 12 powers of 2. He noticed a pattern in the digits in the units places of the results. He said he could use this pattern to predict the digits for 2 to the power of 100.
Penny Nom lui répond.
The circumference of an oval pool 2005-05-18
John pose la question :
I have an oval pool of which I am trying to find the circumference. it is 38 feet long and 19 feet wide
Penny Nom lui répond.
Which is smaller 2^175 or 5^75? 2005-05-18
Sarah pose la question :
Which is smaller 2175 or 575? without using a calculator.
Claude Tardif lui répond.
A six digit answer 2005-05-18
Angela pose la question :
I have a 6 digit answer that is comprised of only 4 symbols: a square, a circle, a triangle, and an X. How many possible solutions are there and how is the best way to find out what ALL the solutions are?
Penny Nom lui répond.
Jobs relating to the topics of ratios and proportions 2005-05-17
Alexa pose la question :
What are some jobs relating to the topics of ratios and proportions other than architects and map makers?
Walter Whiteley lui répond.
Divisibility of a^2 + b^2 2005-05-16
Ampa pose la question :
given natural numbers a and b such that a2+b2 is divisible by 21, prove that the same sum of squares is also divisible by 441.
Penny Nom lui répond.
What is my acreage? 2005-05-16
Vonis pose la question :
My property is 65.5 feet by 130 feet. what is my acreage?
Penny Nom lui répond.
L'hopital's rule 2005-05-15
Abraham pose la question :
Find the limit of [(1/(x+4))-(1/4)]/x as x approaches zero. How do you use l"hopital's rule to find this limit. I know how to do it with multiplying everything by 4(x+4), and getting the answer, -1/16.But how do you apply derivatives with l'hopitals rule to this type of problem?
Penny lui répond.
Angle of incline 2005-05-15
Kyle pose la question :
What is the degree of incline of a 12 foot plank that goes from 10.5 inches on one end to zero inches on the other?
Penny Nom lui répond.
How many cubic feet in a yard? 2005-05-13
Carol pose la question :
How do you measure a cubic foot? How many cubic feet in a yard?
Penny Nom lui répond.
Maximizing revenue 2005-05-13
Jackie pose la question :
1.The manager of a 100-unit apartment complex knows from experience that all units will be occupied if the rent is $400 per month. A market survey suggests that, on the average, one additional unit will remain vacant for each $5 increase in rent. What rent should the manager charge to maximize revenue?

2.During the summer months Terry makes and sells necklaces on the beach. Last summer he sold the necklaces for $10 each and his sales averaged 20 per day. When he increased the price by $1, he found that he lost two sales per day.

a. Find the demand function, assuming it is linear.
b. If the material for each necklace costs Terry $6, what should the selling price be to maximize his profit?


Penny Nom lui répond.
Adding consecutive integers 2005-05-13
Yas pose la question :
i need some help with my work which is to investigating sums of consecutive numbers for example: 15= 4+5+6 and 15=1+2+3+4+5
Penny Nom lui répond.
Surface areas 2005-05-11
Jessica pose la question :
How can I demonstrate to my high school students the reason for the formulas for the surface area of a prism, right cylinder, and regular pyramid, and right cone?
Penny Nom lui répond.
sin x + sin 2x + sin 3x + sin 4x = 0 2005-05-10
Elia pose la question :
I tried many times, but can't get to solve the following question:
sin x + sin 2x + sin 3x + sin 4x = 0

Chris Fisher lui répond.
Some triangle problems 2005-05-06
A student pose la question :
1.use the heron's formula to find area of triangle ABC to nerest tenth

A.a=21 b=28 c=11

B.a=23 b=28 c=12

2.Find the nearest tenth the altitude of the longest side if a=3 b=3 c=5

3.the length of each side of a rhombus is 10 cm the length of one diagonal is 12 cm find the area to the nearest square centermeter

Penny Nom lui répond.
y = x+2 and y = 2x - 1 2005-05-03
Kimberley pose la question :
Question: y=x+2 y=2x-1
Penny Nom lui répond.
16x^2+20x-12x-15 2005-05-03
Tanya pose la question :
how they got (4x+5)(4x-5) from
16x2+20x-12x-15=4x(4x+5)-3(4x+5)=(4x+5)(4x-5)

Penny Nom lui répond.
Graphing an inequality 2005-05-02
Janice pose la question :
I need to know how to graph inequalities. I need to know just abot everything. From graphing an equation to shading.
Leeanne Boehm lui répond.
Two problems 2005-04-29
Sara pose la question :

#1 A boat is traveling in a straight line across a river from point D, directly opposite town P, to a point Q, two thirds of the distance from town P to town R. Towns P and R are towns on the same side of the lake and are 18 miles apart. Line DQ passes through town S, which is 8 miles north of town R. Points P, Q, and R are collinear. What is the length of QS in Miles?
How many miles does the boat travel across the river?

#2 What is the area of a regular hexagon if the perimeter is 24cm?


Penny Nom lui répond.
Volume and surface area of a prism 2005-04-29
Melissa pose la question :
Can you please tell me if the volume and surface area of a prism can ever be the same? Could you please explain why or why not.
Walter Whiteley lui répond.
Area of a region on a map 2005-04-28
Balachandar pose la question :
Pl. find the attached map.

1. Can u pl. find out the total square are of WLMZ
2. Can u pl .find out the total square are of WXYZ -- { A }
3. Can u pl .find out the total square are of XLMY -- { B }

Pl .help me to find out the above.

.....


Chris Fisher and Penny Nom lui répond.
A quadratic equation 2005-04-27
Chris pose la question :
Solve using the quadratic formula

9x² + 9x - 5 = 0
I don't get the same answer as in the text book which is
-3+/- √29/36
Hope you can help....


Penny Nom lui répond.
A 5% increase 2005-04-27
Debra pose la question :
How can I determine the increased percentage of a dollar amount? I.e.: One dollar amount is $202 and another is $150, how can I determine the 5% increase from last year on the $202 dollar amount?
Claude Tardif lui répond.
Cubic yards of sand 2005-04-27
Renee pose la question :
I need to find out how much sand I would need to order for the base of a horse round pen. The pen is 40 ft across and I would like a depth of 4 inches. I have to order the sand in cubic yards.
Penny Nom lui répond.
Probability and smoking 2005-04-24
Sean pose la question :
20% of a certain population smoke. For smokers the probability of dieing of lung cancer is ten times what it is for non-smokers. Over all the probability of dying of lung cancer is .006. Find the probability for smokers and nonsmokers.
Chris Fisher lui répond.
A pyramid 2005-04-24
Marc pose la question :
I'm helping my daughter build a pyramid,it needs to be 30cm in height. I have cut out four pieces at 30 deg angles. When I went to join up the pieces it did not fit. I re-check my measuments and found that they were correct. Do I need to cut two pieces smaller so they can match up? Did I cut them at the wrong angles. My base is also 30cm, is that my problem?
Chris Fisher and Harley Weston lui répond.
An isosceles triangle...with 2005-04-23
Shannon pose la question :
If given an isosceles triangle...with
Is there any possible way to do this, without knowing a side, if so, please explain in detail.

Chris Fisher lui répond.
A pattern of numbers 2005-04-21
Claire pose la question :
We need to be able to discover the nth term in a pattern of numbers and explain how we did it. We have arrived at the formula 1+2+3+...n=n(n+1)/2 for trios where a trio series is;

3 has the following trio (1,1,1)
4 has the following trios (2,1,1), (1,2,1), (1,1,2)
5 has the following trios (3,1,1), (1,3,1) (1,1,3) (1,2,2) (2,2,1) (2,1,2)

So the series is as follows

Penny Nom lui répond.
The least integer of a set of consecutive integers 2005-04-19
Lucia pose la question :
The least integer of a set of consecutive integers is -25. If the sum of these integers is 26, how many integers are in the set?
Penny Nom lui répond.
40% profit 2005-04-19
Carol pose la question :
Could you please tell me the formula to calculate for example a 25% profit on cost. I.e a sandwich cost .75p for the cost of ingredients, I wish to make a 40% profit on that cost so what do I multiply and divide it by to arrive at the selling price in order to achieve a 40% profit?
Penny Nom lui répond.
Percentage increase 2005-04-19
Tom pose la question :
What is the percentage increase from (negative -$9262.00) to (positive $3840.00)?
Penny Nom lui répond.
Centimeters, millimeters and milliliters 2005-04-19
A student pose la question :
How many milliliters in a centimeter?
Penny Nom lui répond.
A Taylor series for ln(x) 2005-04-16
Anood pose la question :
i have to represent ln(x) as a power series about 2

i`m not getting the final answer which is ln 2+ sigma (((-1)(n+1)/ (n*2n))*(x-2)n). i don`t get the ln 2 part

i show you my trial

f(x)= ln x.

f-(x)=(1/x) .

f--(x)= (-1/x2)*1/2!

f---(x)= (2/x3)*1/3!

f----(x)= (-6/x4)* 1/4!

so the pattern shows me that f(n)= ((-1)(n+1))/xn *n)

so f(2)= sigma ((-1)(n+1))/2n *n) *(x-2)n

so as you see i don`t get ln 2


Penny Nom lui répond.
How much sand is in a pile? 2005-04-16
Larry pose la question :
I was wondering if there is a formula for determining how much sand would be in a pile. I am a student in medical school, and this is a bonus question for a test. I hope you can help me.
Harley Weston lui répond.
Some four digit numbers 2005-04-16
Lori pose la question :
can u give me every possible combination of four numbers starting with the number three
Penny Nom lui répond.
A roll of paper 2005-04-16
Tuomas pose la question :
How would you calculate a diameter of a paper reel when the paper is 0,04 millimeters thick and for example 5000 meters of it is winded on a 76 mm (3inch) core.
Penny Nom lui répond.
A flaw in a problem 2005-04-15
Bryce pose la question :

Question:

(x2-x2) = (x2-x2)
x(x-x) = (x+x)(x-x) [divide both sides by (x-x)]
x = x + x
x = 2x [divide both sides by x]
2 = x/x = 1

Where is the flaw in this problem?


Paul Betts lui répond.
X and Y intercepts 2005-04-14
David pose la question :
Hi, i would like to know if you can answer this question for me Find the x and y intercept fo y = 8x - 5
Penny lui répond.
The limit as x approaches 3 of (sqrt(x+1)-2)/(x-3) 2005-04-14
Abraham pose la question :
What is the limit as x approaches 3 of (sqrt(x+1)-2)/(x-3)
Penny lui répond.
cos(2x) = sin(3x) 2005-04-14
A student pose la question :
Show that if x= 18 degrees, then cos2x =sin 3x. HENCE find the exact value of sin 18 degrees, and prove that cos 36 - sin 18 =1/2.
Andrei Volodin, Claude Tardif and Penny Nom lui répond.
Prime numbers 2005-04-11
Jesule pose la question :
Given that p, p+10 and p+14 are prime numbers, find p.
Claude Tardif and Chris Fisher lui répond.
A 25% markup 2005-04-07
Jason pose la question :
I want to markup $2.00 by 25%...How do I do this???
Penny lui répond.
The centroid of a triangle 2005-04-07
Maria pose la question :
Q3)find the coordinates of the centroid of triangle ABC i want your help here to solve the 3rd question i got stuck.
Penny Nom lui répond.
A mixture 2005-04-06
Ray pose la question :
two known values
product # 1 = 60% protein
product # 2 = 80% protein

How much of the #2 product would I need to add to the # 1 product to create a third product of 65%


Penny lui répond.
Difference in latitude 2005-04-05
Gretel pose la question :
Assuming the the earth is a sphere of radius 6378 kilometers, what is the difference in latitude of two cities, one of which is 400 kilometers due north of the other? 500 kilometers?
Penny Nom lui répond.
Rational functions 2005-04-05
Nicole pose la question :
My name is Nicole and I am a teacher at Weyburn Comprehensive School. I am currently teaching both Math B30 and Calculus 30 at the school and I have a question about rational functions. I know that if a rational function (by definition) has common factors in the numerator and the denominator then it is not a rational function (math b30) however in calculus this common factor creates a hole in our graph. Can you explain to me why a common factor or constant does not give us a rational function?
Penny Nom and Leeanne Boehm lui répond.
A matrix problem 2005-04-04
Alan pose la question :
Let A = 1-10
2-12
abc

where a, b, c are constant real numbers. For what values of a, b, c is A invertible? [Hint: Your answer should be an equation in a, b, c which satisfied if and only if A is invertible.]


Judi McDonald lui répond.
Ax + By = C 2005-04-03
Farzana pose la question :
I was wondering if you could please explain to me how I would write the equation of line through the given points [(-3,7), (0,5)] in Ax+By=C form.
Penny Nom lui répond.
Some liquid in a cone 2005-04-03
Vasuki pose la question :
There are 2 right cones, height is X. one of them is filled from the bottom up (round side) = x/2, when you invert the cone and add the same amount of liquid inside the second cone, what is the HEIGHT of the liquid?
Penny Nom lui répond.
Bayes Theorem 2005-04-03
wei pose la question :

In the January 11,1988,issue of the Oil&Gas Journal, R.A.Baker describes how the Bayesian approach can be used to revise probabilities that a prospect field will produce oil. In one case he describes, geological assessment indicates a 25% chance the field will produce oil. Further,there is an 80% chance that a particular well will strike oil given that oil is present on the prospect field.

  1. Suppose that one well is drilled on the field and it comes up dry. What is the probability the prospect field will produce oil?
  2. If two wells come up dry, what is the probability the field will produce oil?
  3. The oil company would like to keep looking as long as the chances of finding oil are greater than 1%. How many dry wells must be drilled before the field will be abandoned
  4. If the first well produces oil,what is the chance the field will produce oil?

Andrei Volodin and Penny Nom lui répond.
Gallons in a tank 2005-04-02
Jim pose la question :
Would you be so kind as to help me with a problem? My memory has failed me in remembering how to calculate how much liquid in gallons a tank will hold. The tank is 8 feet long and 44 inches in diameter.
Penny Nom lui répond.
An asphalt driveway 2005-04-02
Bob pose la question :
I'm trying to convert square feet to cubic yard.
I have an asphalt drive way I'd like to replace with concrete. Concrete is sold by the cubic yard and I keep telling myself that their must be an easy conversion table out there somewhere.

My driveway is 18 feet wide and 47 feet long with a proposed depth of 4 inches.

Penny Nom lui répond.
An inequality 2005-03-31
Ambross pose la question :
demostrate the following inequality:
2.Sqrt(K+1)-2.Sqrt(k)<1/Sqrst(K)<2.Sqrt(K)-2.Sqrt(k-1)

Penny Nom lui répond.
The integral of tan^4x 2005-03-31
Nicole pose la question :
college student. need help with tough integral.

the integral of 2tan4xdx


Penny Nom lui répond.
tan55.tan65.tan75=tan85 2005-03-30
Jesus pose la question :
My name is Jesus and I´m a secondary student. I´m trying to verify a trigonometric identity but I don´t know how to do it.please help me!!!!!!!!!.

The identity is : tan55º.tan65º.tan75º=tan85º (the sign (.) indicates multiplication)


Chris Fisher and Penny Nom lui répond.
Two matrix problems 2005-03-30
Sue pose la question :
Question 1
Suppose all matrices in the equation below are square and invertible. Solve for x .

BA-1XB-1 + 2BA + In = 0 (the symbol "0" here denotes the matrix of all 0's in it)

Also, A-1 or B-1 is indicating inverse and "In" = for example, A-1 times A
I hope you understand the above. I have to show all the steps.

Question 2
Suppose we consider the set of all 2x2 matrices along with the operations of matrix addition and multiplication. Do they form a field? Why or why not?
I think the answer is no because under multiplication it is not commutative and not all square matrices are invertible. I not positive so I'd like some help.

Penny Nom lui répond.
The shortest distance from a point to a line 2005-03-30
carly pose la question :
Find the shortest distance from the point (-15, 2.5) to the line 5x+6y=30.
Penny Nom lui répond.
A wishing well 2005-03-28
Don pose la question :

I am building a wishing-well out of pieces of 2-by-4. I have included a picture of a miniature version of what I want. There are to be ten 2-by-4 pieces around the well and I want the circle around the outside of the structure to have a diameter of approximately 3 feet. How long to I cut the 2-by-4's to build the wishing-well.

Thanks,
Don


Harley Weston lui répond.
Explain why 3(x+2) = 3x+2 is incorrect 2005-03-28
Cynthia pose la question :
An algebra student incorrectly used the distributive property and wrote 3(x+2) = 3x+2. How would you explain to him the correct result, without the use of the distributive law?

Explain why the square of the sum of two numbers is different from the sum of the squares of two numbers.

Penny Nom lui répond.
A product equals a sum 2005-03-27
Tor pose la question :
Can you please help me with a general formula for the following system:
2+2=2*2
3+3/2=3*3/2
4+4/3=4*4/3

and how will you prove the formula?


Penny Nom lui répond.
A torus and a sphere 2005-03-27
Tony pose la question :
Is it possible to shrink a torus into a sphere?
Andrei Volodin and Penny Nom lui répond.
Gasoline in a cylindrical tank 2005-03-23
Jennifer pose la question :

Gasoline is stored in a tank which is a cylinder on its side. Height of fuel is "h" meters and the diameter is "d". The length is "l".

I need to find the amount of gas in the tank when the height is h and also to calculate the fraction of how full it is.

Also, the part I am really confused on is this one,
E(h/d) is the error of the function of h/d, when h/d is used to measure how full the tank is. For what value of h/d is the error maximal?


Penny Nom lui répond.
Expanding (x+2)(x+3) 2005-03-23
Rick pose la question :
The problem involves writing expressions, one in factored form and one in expanded form, for the area of a rectangle of sides x+2 and x+3. We've gotten as far as area = (x+2)(x+3). But I can't come up with the other expression.
Penny Nom lui répond.
Find the height of the pole 2005-03-22
Dorothy Jean pose la question :
From the top of a building 70ft.high, the angle of elevation of the top of the pole is 11.2 degrees. From the bottom of the building the angle of elevation of the top of the pole is 33.4 degrees. Find the (a) height of the pole and (b) the distance from the building.
Penny Nom lui répond.
|ax+b| = cx + d 2005-03-22
Angel pose la question :

|ax+b| = cx + d

how to show sometimes the above has 2 roots, sometimes 1 root and sometimes no roots. Hopelessly lost on how to start...


Penny Nom lui répond.
The answer to a subtraction problem 2005-03-22
Libby pose la question :
What is the name of a number that is the answer to a subtraction problem?
Diane Hanson and Claude Tardif lui répond.
Two overlapping circles 2005-03-20
Safi pose la question :
I have a problem to calculate the area of two overlapping circles because two circles are overlap then how i calculate the overlap area to subtract from the area of both circle.
Penny Nom lui répond.
Tangents to a circle 2005-03-19
Sue pose la question :

You're given the equation to a circle (x-3)2 + (y-3)2 = 4 and you need to do 3 things:
1. Find a point on the circle
2. Construct an equation for a tangent line to the circle and through the point
3. Plot the circle, point and the tangent line on one graph

Penny Nom lui répond.
Dimensions of a roof 2005-03-18
A roofer? pose la question :
A right triangle (roof of a house) has a base of 7 feet and a 22 degree angle. What is the height of the roof and what is the hypothenus of the triangle.
Penny Nom lui répond.
The sum of the digits 2005-03-16
kelsey pose la question :
What is the sum of the digits in the decimal form of 21999 * 52002?
Claude Tardif lui répond.
A matrix construction problem 2005-03-14
Marcelo pose la question :
I want to know if is it possible to solve this problem:
I have an empty NxM matrix and I know totals (sum) by rows and totals by column.
Is there any algorithm to fill the matrix so that the summary of columns and rows gives the original values I have?

Harley Weston lui répond.
If the mixture is 1 pint to 6 gal 2005-03-13
Trey pose la question :
If the mixture is 1 pint to 6 gal. Do i use 4 pints to 24 gallons of gas
Penny lui répond.
The volume of a stock tank 2005-03-13
Cord pose la question :
I am a farmer and I have recently installed a new stock tank which is 1650" in circumference and 10' deep. How many gallons of water will it hold?
Penny Nom lui répond.
The square root of 2 2005-03-12
Madhumita pose la question :
From Pythagoras theorem we can draw square root 2 as a finite distance but it is irrational number which is endless. Explain how we can equate these two.
Harley Weston lui répond.
Doubling time 2005-03-12
Nick pose la question :
Looking for the equation to how many years it will take to double the population given the growth rate is 7%.
Penny Nom lui répond.
How many three digit numbers can I make from the four cards 2005-03-12
Sue pose la question :
I have four playing cards 2,3,4,5 of hearts. How many three digit numbers can I make from the four cards.
Penny Nom lui répond.
The benefits of saving for retirement 2005-03-11
Nick pose la question :
A human resources department wants a report that shows its employees the benefits of saving for retirement. Produce a report that shows 12 predicted retirement account values for each employee - the values if the employee saves 5, 10, or 15% of his or her annual salary for 10, 20, 30, or 40 years. Assume that savings grow at a rate of 8% per year. Not really interested in answers, just the equations to solve the problems.
Penny Nom lui répond.
The ratios of Business, Accounting and Engineering majors are: 7:8:10. 2005-03-11
John pose la question :
There are 500 students in a collage class. The ratios of Business, Accounting and Engineering majors are: 7:8:10.

How many Engineering majors are there in the class?


Penny Nom lui répond.
21yd 2ft divided by 5=what? 2005-03-10
A student pose la question :
1gallon 3qt divided by 6= what?
21yd 2ft divided by 5=what?

Penny Nom lui répond.
Discrimination based on gender? 2005-03-10
A student pose la question :
After being rejected for employment, Kim learns that the Bellevue office has hired only two women among the last 20 new employees. She also learns that the pool of applicants is very large, with an approximately equal number of qualified men and women. Help her address the charge of gender discrimination by finding he probability of getting two or few women when 20 people are hired, assuming that there is no discrimination based on gender. Does the resulting probability really support such a charge?
Penny Nom lui répond.
A wrestling schedule 2005-03-08
Ed pose la question :
Hello my name is Ed and I am a couch of a wrestling team in New Jersey. I was doing searches for formulas on how to make a matrix for team sports and it seems to be hard to find. I came some how to your site and thought I'll give it a try. Here is what we need or are trying.
Claude Tardif lui répond.
A nine week schedule 2005-03-08
Greg pose la question :
I'm trying to build a nine week schedule where 10 teams play each other once throughout the season.

I make it all the way to week nine, then I start having all sorts of conflicts.

HELP!!


Claude Tardif lui répond.
Biodiesel 2005-03-08
William pose la question :
My son is doing an demonstration for science class about how to make biodiesel. we are having problems with the conversion. for instance we think there are approx 190 liters in 50 gallons. Is this correct? Also if you needed 3.5 grams of lye per liter, would that be 662g of lye.
Penny Nom lui répond.
The cost of concrete 2005-03-08
Cathy pose la question :
Compute the cost of ready mixed concrete for a driveway 70ft long, 10ft wide, 3 inches deep at a cost of $30.00 per cubic yard
Penny lui répond.
A diagonal in a cube 2005-03-06
Brett pose la question :
A cube has a volume of 64 cubic inches. What is the length of segment AB? Segment AB is a straight line from the top left corner of the cube to the lower right bottom corner
Penny Nom lui répond.
Perfecting an ideal gambling system 2005-03-06
Gaz pose la question :
I am a screenwriter, currently in the fortunate position of having the development of a Screenplay funded by the South Australian Film Corporation. The (anti)hero of this screenplay is a statistician whose life is falling apart around him, thanks in part to his obsession with perfecting an "ideal" gambling system.
Andrei Volodin lui répond.
A trig identity 2005-03-06
Patrick pose la question :
im trying to verify this identity:

sin(x)+sin(5x)
-------------------- = tan(3x)
cos(x)+cos(5x)


Chris Fisher lui répond.
I need to fill an area with rock 2005-03-04
Kelly pose la question :
if I need to fill an area with rock that is 64 feet long by 4 feet wide and 1 foot 2 inches in depth
how many tons of rock will this job require?
it is also sold by cubic yard how many of these cubic yards will I need?

Penny Nom lui répond.
Spraying roses 2005-03-03
A student pose la question :
A litre and a half of water has 0.045 grams of herbicide added for spraying roses. How many grams of herbicide per litre is this?
Penny Nom lui répond.
How much of a acre is this? 2005-03-02
Ken pose la question :
my property is 11,914 square ft. How much of a acre is this?
Penny Nom lui répond.
Reverse pecentage 2005-03-01
Nathan pose la question :
Question for you. If I have spent $10.00, what is the mathamatical equation to
figure out what the G.S.T (7%) was?

Also if I were to spend $80.00 on a hotel, and I would like to know how much
G.S.T (7%) and how much provincial tax (6%) I spent how would I go about this.


Penny Nom lui répond.
The area of a quadrilateral 2005-02-27
Jonathan pose la question :
I want to know how to find the area of a quadrilateral.
Penny Nom lui répond.
A triangle question 2005-02-26
John pose la question :
H=10' 7and3/4",angleX=30 degrees solve for the adjacent side
Penny Nom lui répond.
A countably infinite collection of countably infinite sets 2005-02-26
Feroz pose la question :
Suppose a set can be divided into a countably infinite number of countably infinite sets.Then can the original set be considered as a countably infinite set?
Penny Nom lui répond.
A 3-digit product 2005-02-25
A student pose la question :
I have an odd 3- digit product. My factors are a 1 digit number and either a 2 or 3 digit number. My factors are odd, but neither is 1. Find my factors and my product.
Penny Nom lui répond.
The volume of a sphere 2005-02-25
Stephanie pose la question :
find the volume of a sphere that has a diameter of 12 cm. please show me how to work this problem
Penny Nom lui répond.
Trading fish for bread 2005-02-25
Mike pose la question :
Byron lives where people trade goods they produce for other things they need. He has some fish and wants to trade them for bananas. He finds the following:
5 fish = 2 loaves of bread
6 oranges = 2 melons
1 loaf of bread = 1 banana and 3 oranges
4 loaves of bread = 14 oranges
How many bananas can Byron get with 5 fish?

Penny Nom lui répond.
Cubic feet and feet 2005-02-25
Nancy pose la question :
How do you convert cubic feet into feet?

The problem is to convert 90 cubic feet into feet.

Penny Nom lui répond.
The capacity of a dryer 2005-02-23
Darlene pose la question :
I am trying to figure out the capacity of my dryer. I need to know the size in order to buy a new one. The drum within measures 27" in diameter and 18" deep. I know that I am looking for an answer in cubic feet but am not sure how to determine this.
Penny Nom lui répond.
An irregular pentagon 2005-02-23
Tony pose la question :
Please help me with confirming the area in square footage of the irregular pentagon

My Name is Tony and I am working on understanding the square footage as calculated in the drawing. I also believe this is a secondary level question.

I saw the example http://mathcentral.uregina.ca/QQ/database/QQ.09.03/dana2.html and would appreciate how you worked through the problem, but couldn't find the calculations so that I could adapt them to my sizes.

Penny Nom lui répond.
13 puissances 2005 2005-02-22
Un eleve pose la question :
je voulais vous demander combien fait 132005
(13 puissances 2005) svp

Claude Tardif lui répond.
Each interior angle of a particular polygon is an obtuse angle... 2005-02-22
Victoria pose la question :
Each interior angle of a particular polygon is an obtuse angle which is a whole number of degrees. What is the greatest number of sides the polygon could have?
Walter Whiteley lui répond.
Grams per liter 2005-02-20
A student pose la question :
A litre and a half of water has 0.045 grams of herbicide added for spraying roses. How many grams of herbicide per litre is this?
Penny Nom lui répond.
Factoring a cubic 2005-02-20
Abraham pose la question :
How would you factor completely,
x3-x2+5x-5?

Claude Tardif lui répond.
$14k is 22% of ________ 2005-02-19
A parent pose la question :
When one knows the
percentage, and a known number, how is the unknown total figured? In other words, I know that $14k is 22% of what number??

Claude Tardif and Penny Nom lui répond.
1 pied linéaire 2005-02-18
Christiane pose la question :
Pouvez-vous m'indiquer 1 pied linéaire égale quoi? 3 pied....?
Claude Tardif lui répond.
Graphing inequalities 2005-02-15
Melanie pose la question :
Solve and Graph the following variable inequalities:

y<2x+4

y>-2x+6

3x+4y<-24

4x-6y>-24

Penny lui répond.
The weight of some concrete 2005-02-15
Jordan pose la question :
I have 6 acres of concrete that is 3 feet thick the aprox. weight of 1 cubic yard of concrete is 4024 pounds I am trying to find out how much my 6 acres weighs. fortunately my concrete is 3 feet deep.
Penny Nom lui répond.
If the distance of a person from a tower is 100 m... 2005-02-15
Agustin pose la question :
If the distance of a person from a tower is 100 m and the angle subtended by the top of the tower with the ground is 30 degrees, what is the height of the tower in meters?
Harley Weston lui répond.
One million times one billion 2005-02-15
A student pose la question :
How much is ONE MILLION TIMES ONE BILLION in the American system ?
Penny Nom lui répond.
What is the least three-digit palindrome that is a square number? 2005-02-12
Ben pose la question :
What is the least three-digit palindrome that is a square number?
Chris Fisher and Penny Nom lui répond.
Understanding fractions 2005-02-11
C.J. pose la question :
I have some questions about the lesson, "Understanding Fractions" by Diane Hanson, Regina Catholic Schools. How successful was the lesson? Are there any changes you would recommend?
Diane Hanson lui répond.
arcsech x 2005-02-10
Monica pose la question :
Prove that arcsech x = ln[(1 + (1-x2)(1/2)) / x ]
Penny Nom lui répond.
Th dimensions of a garden 2005-02-09
Rebecca pose la question :
Nate's garden has a perimeter of 34 meters and an area of 72 square meters. What are the dimensions of the garden?
Penny Nom lui répond.
Sales before tax 2005-02-09
Lynda pose la question :
I know my total sales for the month, which includes sales tax. How do I get to the sales dollars before the sales tax?
Penny Nom lui répond.
A quadratic equation 2005-02-09
Jess pose la question :
6x+8=-x2
Claude Tardif lui répond.
A combination lock has 60 positions... 2005-02-07
Kathy pose la question :
A combination lock has 60 positions arranged in a circle to which a pointer may be set. Three settings are required to open it and no one setting may be closer than 5 positions from the immediately preceding setting. How many different locks may be manufactured?
Penny Nom lui répond.
Conversion of a recipe 2005-02-06
Peg pose la question :

A Hungarian friend gave me an old, old family recipe and it calls for:

20 dg. sugar

15 dg. filbert

I can't find a conversion table anywhere that explains how to get ounces from "dg." Do you know what the equivalent would be in ounces of dry measurement?


Harley Weston lui répond.
Extraneous solutions 2005-02-04
Heather pose la question :
My teacher wants to know why there are extraneous solutions in logarithms?
Penny Nom lui répond.
A seating arrangement 2005-02-03
Kay pose la question :
If you have 5 married couples, how many arrangements can be made if they must sit across from each other?
Penny Nom lui répond.
Three debts 2005-02-03
Kat pose la question :
If I have three debts and 49% percent of total debt is loaned at 9% intrest, 34% of the debt is at 21% intrest and 17% of the total debt is at 14% intrest, how do I calculate the average rate of intrest on total debt?
Penny Nom lui répond.
Strategies for teaching operations with positive and negative decimal numbers 2005-02-02
Erin pose la question :
I am wondering if you can suggest any strategies for teaching operations with positive and negative decimal numbers that do not rely on rules that must be memorized?
Diane Hanson lui répond.
The diaonals of an isosceles trapezoid are congruent 2005-02-02
Daniel pose la question :
I am currently unable to find a proof that the diaonals of an isosceles trapezoid are congruent. Might you happen to have one?
Walter Whiteley lui répond.
Solve for x 2005-02-02
Christie pose la question :
Solve for x

.387 = (.40 - .265x)/(sqrt(1-x2))

Penny Nom lui répond.
A line segment connecting two vertices of a polygon 2005-02-02
James pose la question :
What is a line segment (not a side) connecting two vertices of a polygon called?
Penny Nom lui répond.
The volume of an aquarium 2005-02-01
Selena pose la question :
Im trying to figure out the amount of gallons from a rectangle 48x20x12?
Penny Nom lui répond.
'zero divided by one' and 'one divided by zero' 2005-01-31
Katrina pose la question :
Please advise how best to explain the distinction between the solution to 'zero divided by one' and 'one divided by zero'. I remember being told in school that one of them is undefined and the other is zero but I'm having difficulty with calculating and explaining it to some highly curious 10 year olds!
Claude Tardif and Walter Whiteley lui répond.
Are the vetices of this quadrilateral concyclic? 2005-01-30
A student pose la question :
Show that the peints A(-2,0),B(6,6),C(-1,7) and D(-2,6) are concyclic. Also find its circum radius.
Chris Fisher lui répond.
Sum to n terms of the series i.(2^(n-i)) 2005-01-28
Satya pose la question :
Sum to n terms of the series i.(2n-i)
Penny Nom lui répond.
Some logarithm problems 2005-01-27
Jo pose la question :
Given ln x=7.1; ln y=8.2, Find ln(x^3y^7)
Penny Nom lui répond.
By how much is 100 multiplied or divided,... 2005-01-27
Benedict pose la question :
By how much is 100 multiplied or divided, so that whether the number obtained is divided by 5 or 7, there will be a remainder of 1 and so that at the same time, the first quotient is greater by 4 than the second?
Penny Nom lui répond.
Approximating an integral 2005-01-27
A student pose la question :
i used excel to find the area under a graph instead of integrating the function the analytical way. These are the different answers i got with different width of the x-values, the smaller the x-increment gets the more precise the area is when compared to the answer obtained the numerical way. I have trouble seeing why the answers i get is getting bigger and bigger and not smaller can someone plz explain?
Penny Nom lui répond.
A combination question 2005-01-26
Kelly pose la question :
A computer with an old processor locks up if more than 4 applications are running at the same time. If the owner has 20 applications stored in his program file, how many different sets of 4 can he run, so that his computer does not lock up?
Penny Nom lui répond.
un nombre entier 2005-01-25
Un eleve pose la question :
comment démontrer qu un nombre entier est un carré parfait si et seulement si il admet un nombre impair de diviseurs?
Claude Tardif lui répond.
Three tangent circles 2005-01-25
Kate pose la question :
Two circles, C1 and C2, touch each other externally; and the line l is a common tangent. The line m is parallel to l and touches the two circls C1 and C3. The three circles are mutually tangent. If the radius of C2 is 9 and if the radius of C3 is 4, what is the radius of C1?
Chris Fisher lui répond.
Differentiating F(x,y) = 0 2005-01-23
Jacob pose la question :
In calculus, we often mention to the students that if F(x,y) = 0, then we can differentiate both sides and still get an equality. The problem is that we can't perform the same operation on F(x) = 0, say x = 0, otherwise 1 = 0, which is absurd. What is the reason?
Walyer Whileley and Harley Weston lui répond.
cos 2x = sin x 2005-01-22
Kris pose la question :
solve the equation
cos 2x = sin x for 0<= x < 360

Penny Nom lui répond.
When dividing a 3-digit number by a 1-digit number... 2005-01-22
A student pose la question :
When dividing a 3-digit number by a 1-digit number, for what divisors can you get a remainder of 8?
Penny Nom lui répond.
The diameter of a 800 km circle 2005-01-22
Mechelle pose la question :
What is the diameter of a 800 km circle?
Penny Nom lui répond.
A 6 sided (hexagonal) pyramid 2005-01-22
Steve pose la question :
im trying to make a 6 sided (hexagon) pyramid, from 6 triangles of 12mm plywood, i know all the angles to cut apart from the one one to join all 6 triangles together. Rough measurements are outer edge (A) of each triangle is 13cm's, length of other 2 sides (B&C) of triangle outside to center is 14cm's with a height of the whole thing together about 6cm's.
Chris Fisher and Harley Weston lui répond.
The area of a triangle 2005-01-21
Amy pose la question :
In tirangle ABC, AB=6, BC=9, BC is the angle bisector of angle ABC and M is the midpoint of BD. If the area of ABC is 30, what is the area of ABM? The height comes out greater than the hypotenuse, but the teacher said that there's an answer for it. Can you show me how? Thanks
Chris Fisher lui répond.
Finding the missing side of a triangle 2005-01-20
Jason pose la question :
I found a geometry problem that reads as follows:In triangle ABC,
Penny Nom lui répond.
The angle between two forces 2005-01-19
Abraham pose la question :
One force of 20 pounds and one force of 15 pounds act on a body at the same point so that the resultant force is 19 pounds. Find, to the nearest degree, the angle between the two original forces.
Penny Nom lui répond.
The radius of a circle 2005-01-18
A student pose la question :
find the radius of a circle whose area is 1256sq cm.Use pi as an appoximation for pi.
Penny Nom lui répond.
A non-rerctangular lot 2005-01-18
EM pose la question :
One corner of a 60X120 foot lot, otherwise rectangular, is a curve with a radius of 20 feet and a central angle of 90 degrees. What is the area?
Penny Nom lui répond.
The side of a cube 2005-01-17
Jake pose la question :
I have one for you that's got me stumped. Is it possible to calculate the dimensions of a square if I have the cubic feet? Say I know the package to be 180 cubic feet.
Penny Nom lui répond.
Stewart's Theorem 2005-01-17
Amy pose la question :
In triangle ABC, AB=4, AC=6 and AD=5, where D is the midpoint of BC. Determine BC.
Chris Fisher lui répond.
Numbers that John likes 2005-01-16
Garrett pose la question :
John likes 400 but not 300; he likes 100 but not 99; he likes 3600 but not 3700. Which does he like?

900
1000
1100
1200

Penny Nom lui répond.
The area of a trapezoid 2005-01-15
Doak pose la question :
What is the total acreage of a pie-shaped piece of land that is:
146' f
ront 85' back
246' each side

The front and back lines are fairly straight....a trapezoidal shape.

Penny Nom lui répond.
The length of a chord 2005-01-13
A parent pose la question :
Does anyone have a formula for calculating the chord length for a segment of a circle when you know the radius and the enclosed angle or radian ?
Penny Nom lui répond.
The tide at a boat dock 2005-01-11
Abraham pose la question :
The tide at a boat dock can be modeled by the equation

y = -2cos(pi/6 t) + 8,

where t is the number of hours past noon and y is the height of the tide, in feet. For how many hours between t=0 and t=12 is the tide at least 7 feet?

Penny Nom lui répond.
The game of 24 2005-01-10
Manny pose la question :
HI - my daughter and I are being driven crazy by the following "24" question 7,7,3,3. She's good at the game (well, better than I am) and her teacher gave her this one. Any insight would be appreciated!
Claude Tardif lui répond.
Profit 2005-01-10
Abraham pose la question :
The profit a coat manufacturer makes each day is modeled by the equation P(x)=-x2+120x-2000, where P is the profit and x is the price for each coat sold.For what values of x does the company make a profit?
I don 't understand this problem(how to do it) and hope you can help me.

Penny Nom lui répond.
Arcs and chords 2005-01-09
Aniesha pose la question :
A chord of a circle is 48 centimeters long and is 10 centimeters from the center of the circle. Find the radius?
Penny Nom lui répond.
Acres 2005-01-08
Jim pose la question :
What size is this lot?
And is there a location on the web where you can plug in lot dimensions to figure acreage?

North = 180ft
South = 210ft
West = 336ft
East = 244 ft

Harley Weston lui répond.
ln(hx+n) 2005-01-07
Anibal pose la question :
if I have the eq. y=hx+n and I want to know ln(y), how do I process ln(hx+n)?
Penny Nom lui répond.
Quadratics 2005-01-05
Usman pose la question :
Hi, in my Grade 11 Functions math class we have been assigned the task of finding jobs and careers related to quadratics, I have done many searches but have been unsuccessful, then I saw your website and e-mailed. I also have to use an example of a math problem that the job uses, then solve it, this will all compile on bristol board for a presentation. I would greatly appreciate it if you could send me some links and references of sources that refer to this subject.
Harley Weston lui répond.
There are 4 contestants in a bicycle race. 2005-01-05
Robert pose la question :
There are 4 contestants in a bicycle race. In how many different orders can they cross the finish line?
Penny Nom lui répond.
Express the answer in dollars 2005-01-03
Abraham pose la question :
My question on this question is if I wrote just 5280 because they say they want it in dollars, is that correct or is the only answer, 5279.61 as their answer key says? How should I have known to give it with cents? Should I give myself full credit?
Harley Weston lui répond.
An isosceles triangle 2005-01-03
Abraham pose la question :
The question is,"Triangle ABC is not isosceles.Prove that if altitude BD were drawn, it would not bisect AC."My question is If an altitude is drawn wouldn\'t that mean automatically its isosceles because, In a triangle the sides opposite congruent angles(in this case the right angles)are congruent? What am I thinking wrong?
Harley Weston lui répond.
A sequence of transformations 2005-01-03
Abraham pose la question :
Please go to this web site and look at number 31.

http://www.nysedregents.org/testing/mathre/matharch/mathbtestau02.pdf

That is the New York state education web site. Can you tell me if my answer would be marked correct? My answer was Transformation of 4,-3 (T 4,-3) followed by a reflection in the x-axis.If I graphed the question and wrote that, would I get full credit

Harley Weston lui répond.
An elliptical table 2005-01-03
Roger pose la question :
Want to make an elliptical table, say the long (major) axis is 4 feet, and the short (minor) axis is 3 feet. I can construct this figure, but I'm trying to figure out what the exact dimension of a rectangle within this ellipse will be if I make the table a drop leaf type where the drop dimensions are equal for each end of both the long and short axes. Intuitively, it looks like there is one and only one solution.
Penny Nom lui répond.
Standard deviation 2005-01-02
Urial pose la question :
Find the standard deviation of the given data set
To get the best deal for CD dealer, Jessica called eight appliance stores and asked the cast of a specific model. The prices she quoted are listed below.

$300, $203, $272, $332, $440, $119, $129,$254

Penny Nom lui répond.
A 4-digit access code 2005-01-02
Missi pose la question :
I need to find the 4 digit number to access my voice mail. These numbers will be 0-9 & numbers can be repeated. Could you provide me with a list of possibly combinations? If not, do you know anywhere that I could get a list of combinations so I don't have to write it all down?
Harley Weston lui répond.
A line from the center of the patch to the periphery 2005-01-01
Sandrine pose la question :
I am currently researching a patch disease of grasses. These patches are roughly circular. I need a term for a line from the center of the patch to the periphery. Since the patches are not perfectly circular, my supervisors tell me I cannot use the word 'radius'. What else could I use?
Denis Hanson and Harley Weston lui répond.
A geometry problem 2005-01-01
Alexandra pose la question :
In triangle ABC, b=40, and angle A= 30 degres. What values of BC will give two solution for angle B?
Penny Nom lui répond.
The golden ratio 2004-12-31
Cristina pose la question :
let x represent the longer segment. to find the golden ratio, write a proportion such that the longer of the two segments is the geometric mean between the shorter segment and the entire segment.Use the quadratic Formula to solve the proportion for X. Find the value in both radical and decimal form.
Penny Nom lui répond.
The area of a triangle 2004-12-30
Perry pose la question :
What is the area of a triangle with dimensions 3"X5"X7"? Could you provide the formula?
Penny Nom lui répond.
Gallons in a cylinder 2004-12-29
Dean pose la question :
I have 2 cylinders:
Cylinder A = 8'D x 12'H
Cylinder B = 10'D x 15'H


Each 1ft represents how many gallons of fluid?

Cylinder A=?

Cylinder B=?

Penny Nom lui répond.
Cubic yards of dirt 2004-12-28
Stephen pose la question :
How many cubic feet or yards of dirt would be required to cover a 5 acre tract of land to a depth of 10 feet of compacted dirt?
Penny Nom lui répond.
Six digit numbers with at least one 7 2004-12-27
Behzad pose la question :
How many six-digit numbers contain at least one 7 in their decimal expansion?
Penny Nom lui répond.
2^9833 days from today 2004-12-26
Pauline pose la question :
Today is Monday, 1 October 2001. What day of the week will be 29833 days from today?
Penny Nom lui répond.
Half of five 2004-12-26
Pauline pose la question :
Why is four half of Five? Hint: It's the middle half?
Penny Nom lui répond.
Modelling monthly temperature with a cosine 2004-12-25
Regis pose la question :
The average monthly temperature for a location in Ontario as a function of month number can be modelled using the equation y = a cos[k(t + b)] + d.
Harley Weston lui répond.
An arithmetic progression 2004-12-24
A student pose la question :
the 4th and 5th term of an arithmetic progration 47 and 52 respactively find
a)d
b)a1
c)a50

Penny Nom lui répond.
Irrigation and a sector of a circle 2004-12-23
Chuck pose la question :
A friend of mine is a farmer and uses Pivots to irrigate portions of his land. The crop rows are in straight lines that all form chords of a large circle. The intent is to determine area between any two "boundary" rows expressed in acres.
Harley Weston lui répond.
252 x ? is a cube 2004-12-22
Andrea pose la question :
What is the smallest positive interger by which 252 can be multipled so the result is a perfect cubed?
Penny Nom lui répond.
Making the number 99999 2004-12-22
Lisa pose la question :
Make as many equations as possible to make the number 99999 using all of the numbers 0-9 but only once per equation. example 01234 + 98765 = 99999 she needs to make 150+ equations.
Paul Betts lui répond.
A Reuleaux triangle 2004-12-22
Bob pose la question :
I am trying to remember the name given to the regular figure constructed from three arcs. The figure is like an equilateral triangle except with arcs for each side.
Chri Fisher lui répond.
Divisibility by 15 2004-12-19
Lisa pose la question :
My son was asked to find divisiblity rules for 15. We have been unable to find the answer. Does it exist?
Leeanne Boehm and Denis Hanson lui répond.
The gradiant of a hill is 9% 2004-12-18
Jim pose la question :
The gradiant of a hill is 9%. What angle is created by the run/rise of the hill and 0 degrees?
Penny Nom lui répond.
Two intersecting lines 2004-12-18
James pose la question :
Imagine a vertical line 1.107' tall. Leaving the top of this line, sloping down to the right at a 4:1, at what horizontal distance will the line strike a second line, which leaves the the bottom of the vertical line sloping down to the right at a rate of .02 ft/ft (or 2%)? There is a fairly easy solution to this, but I have lost my notes!
Harley Weston lui répond.
A two equation fact family 2004-12-17
Tony and Hailey pose la question :
My Daughter Hailey had this question as part of her 4th grade math homework. Name 2 fact families that have only two equations. For the life of me I can't figure it out. Any ideas?
Penny Nom lui répond.
0.999..., asymptotes and infinity 2004-12-17
Mike pose la question :
My Name is Mike and I teach high school. I had a student ask me to explain why .9 repeating is equal to 1. Then he asked me about an asymptote, or why a parabola or any other curve for that matter can continually approach a value (like 1) and yet never attain a value of 1. He is thinking that these two should represent the same concept and yet they contradict each other. Do you have a solid explanation for him? Of by the way he is a 7th grader. Great little thinker!!!!!
Claude Tardif and Harley Weston lui répond.
2^10 = -1/2^x - 1 2004-12-13
Randy pose la question :
Could you explain to me how the following equation is solved please.

2^10 = -1/2^x - 1

Harley Weston lui répond.
ln(x)/x 2004-12-11
Tina pose la question :
What is the derivative of (ln x)/x? The double derivative?
Penny Nom lui répond.
A geometric proof 2004-12-11
Hanna pose la question :
Given: ABCD is a quadrilateral;
Prove: ABCD is a parallelogram

Penny Nom lui répond.
A sequence 2004-12-11
Amanda pose la question :
Find the nth term of the following sequence

4, 10, 28, 82

Penny Nom lui répond.
Three calculus problems 2004-12-09
Ashley pose la question :
Hi, I am having a lot of trouble with three calculus questions and was wondering if you could help
Penny Nom lui répond.
Strings of 4 digits from 1,2,...,7 2004-12-09
Tom pose la question :
How many different combinations can be made of the numbers 1-7 in 4 string combinations in any order? EX:7-2-3-5, 3-5-1-7, etc...
And if you were to include the same 2 numbers in every combination, how many would that make? EX: Using 1 & 2: 1-2-7-4, 5-1-4-2, 2-7-5-1, etc...

Penny Nom lui répond.
Combinations 2004-12-09
Keith pose la question :
i have a bucket that can hold 12(or x) number of rocks. if i have 13(or y) rocks how many different combinations of rocks can i put in the bucket without having the exact same 12(or x) rocks in the bucket. is there a formula that can be used for this problem in all cases and if so how and why does it work.
Penny Nom lui répond.
A regular hexagon is inscribed in a circle. 2004-12-08
Abraham pose la question :
A regular hexagon is inscribed in a circle. What is the ratio of the length of a side of the hexagon to the minor arc that it intercepts?
(1) pi/6
(2) 3/6
(3) 3/pi (This is the correct answer.)
(4) 6/pi
I found the length of the minor arc to be (pi)(r)/3 by doing a sixth of the circumference(2pi r).But I can't find the length of the radius to finish off the problem. If I knew the radius I would then plug it into the above and then use the radius again to be the length of the side because the triangle(one of the six of a hexagon) is equilateral. But can you show me how to get the radius to be 3? Thank you so much.

Walter Whiteley lui répond.
A belt around two pulleys 2004-12-07
Ian pose la question :
a belt is stretched around two pulleys whose centers are d units apart and whose radii are R and r respectively (obviously R+r<d). the challenge is to find the length of the belt, l as a formula in terms of R, r, and d only.
Penny Nom lui répond.
An arc of a circle 2004-12-05
Ruben pose la question :
i have an arc 55 inches wide, 12 inches high at the centerline of the arc. how can i determine the diameter of the circle that would correspond to the arc.
Penny Nom lui répond.
Geometric sequence 2004-12-04
Lesa pose la question :
Find a formula for the geometric sequence: (√3 - √2), (4 - √6), (6√3 - 2√2), …
Penny Nom lui répond.
Probability 2004-12-04
A parent pose la question :
Consider a 30 sided polygon. If three diagonal are selected at random, what is the PROBABILITY that they share a common endpoint?
Denis Hanson lui répond.
"a" cubed minus "b" cubed 2004-12-02
Denise pose la question :
"a"cubed minus "b"cubed equal (a-b) times
("a"squared plus "ab" plus "b"squared)?

I know this is a formula, but why is it true?

Penny lui répond.
Select a card from the deck. 2004-12-02
Heidi pose la question :
Select a card from the deck. What is the probability that this card will be red? Show the number of expected outcomes versus the number of total possible outcomes. What type of event does this represent?
Penny lui répond.
1/x + 1/y = 2/31 2004-12-01
matt pose la question :
I have this problem which I think is a bit more tricky than usual. x and y are positive integers.

1/x + 1/y = 2/31

Claude Tardif lui répond.
e = ln(b/a) solve for a 2004-12-01
Daniel pose la question :
I am trying to make "a" the subject of this equation "e = ln(b/a)" but am not sure if i'm doing it right. Any help would be appriciated,
Claude Tardif lui répond.
The volume of a sphere 2004-11-30
Lyndsay pose la question :
twenty cubic metres of air are pumped into a spherical hot air balloon with each given diameter: 1.0m; 2.0m; 3.0m; 4.0m; 5.0m;6.0m
a)calculate the new diameter, new suface area, and new volume of each balloon.

Penny Nom lui répond.
The substitution method 2004-11-28
A student pose la question :
I Was working and i ran into this problem can you help me solve it using the substitution method?

-3x-2y=-10
x+5y=-27

Penny Nom lui répond.
The tangent line at an inflection point 2004-11-28
Louise pose la question :
the equation of the tangent line to the curve y = x3 - 6x2 at its point of inflection is...
Penny Nom lui répond.
Computing confidence intervals 2004-11-26
Christie pose la question :
I was given a question with N=100, sample proportion is 0.1- compute the 95% confidence interval for P? I have tried this several ways but do not know how to do without means, standard deviations, standard error of the mean? I asked my teacher and she said I have all the info I need. Can you help????
Penny Nom lui répond.
A right triangle 2004-11-24
Bruce pose la question :
In triangle ABC.
Angle ABC is 90 degrees.
Side AB measures 34.
Side BC measures 31.
What does side AC measure?

Penny Nom lui répond.
Slicing cubes 2004-11-23
Anthony pose la question :
You are working with a power saw and wish to cut a wooden cube 3-inches on aside into 27 1-inch cubes. You can do this by making six cuts through the cube keeping the pieces together in the cube shape. Can you reduce the number of necessary cuts by rearranging the pieces after each cut?
Chris Fisher lui répond.
Cost before the markup 2004-11-23
Norman pose la question :
the sum of eg $130 includes the markup of 30%. However I need to calculate the percentage to apply to the $130 to assess the cost ie $100.
Penny Nom lui répond.
A graph with certain properties 2004-11-22
A student pose la question :
i was asked as a question in coursework to sketch the graph with the following characteristics:
a double root at -3
a pair of imaginary roots
an x-intercept at 6
a root at 4 which is not a double root

Penny Nom lui répond.
Combinations 2004-11-22
Vivek pose la question :
Show that

10C0 + 10C1 + 10C2 + 10C3+.....10C10 =1024

Penny Nom lui répond.
The length of an arc 2004-11-21
Daryl pose la question :
I am tying to find the arc length of a line 6' and the vertex of the arc 1' off of the line. that is all that is known
Penny Nom lui répond.
Is a square a rectangle? 2004-11-21
Carol pose la question :
I am a teacher. In an FCAT sixth grade review test, there was a question to the students to draw a square and then they referred to it as a rectangle.

What is the definition that makes a rectangle a square that can be taught to the students without confusing them.

Walter Whiteley lui répond.
Proof by induction 2004-11-20
Vic pose la question :
Problem: Find the first 4 terms and the nth term of the infinite sequence defined recursively as follows:

a(1) = 3 and a(k+1) = 2a(k) for k -> 1.

Note: Quantities in brackets are subscripts
-> means 'equal to or greater than'.

Using the recursive formula, the first 4 terms are; a(1) = 3, a(2) = 6, a(3) = 12, a(4) = 24

The nth term a(n) = 2n-1 x 3 (equation 1)

Equation 1 must be proven using mathematical induction. This is where I am having a problem.

Penny Nom lui répond.
Solving quadratics 2004-11-20
Aaron pose la question :
Can you solve the following equation (quote the value of x,y and t to 3 sig figs)

((i have changed figures so that i can work through my own example))

x2 + x - 6 = 0

5y2 +19y = 3 10cos2 t + 3cos t = 4

Penny Nom lui répond.
Construction of a cone 2004-11-20
John pose la question :
I am a builder working on a project where I need to make a cone. It's a right circular cone with 15" base radius and slant angle of 30 degrees. I want to cut it out of flat sheet metal then bring the edges together to form the cone. Is this enough information?
Penny Nom lui répond.
A sequence 2004-11-19
Liucy pose la question :
Find the Nth term: 10 40 90 160 250
Penny Nom lui répond.
Volume of a box 2004-11-18
Catherine pose la question :
I need to find a formula to calculate the amount of liquid would hold. maybe the volume or something. its a square box used to hold liquid on a farm . we want to measure how much liquid it can hold.
Penny Nom lui répond.
1/4 tsp salt = ??? grams 2004-11-16
Julie pose la question :
if i have 1/4 teaspoon of salt how many grams does that equal
Penny Nom lui répond.
Equations involving radicals 2004-11-16
Merin pose la question :

I am quite confused about solving radical equations. This is what I understand:
___
V x-3 = 3

Then you would square each side to get ride of the radical sign and then you solve the problem from there. (x=12 right?)

However, what about a problem with two radicals? For example:
___ ____
V x-2 + V 3x-3 = 3

No matter what I try I cant get the right answer!! Please help!!!


Penny Nom lui répond.
Interior and exterior angles of a polygon 2004-11-16
Aaron pose la question :
How do you find the measure of interior and exterior angles of a regular polygon when you are given the number of sides?
Walter Whiteley lui répond.
Planting trees 2004-11-15
Heather pose la question :
Design a plan of how it would be possible to plant 10 trees in 5 rows, and have 4 trees in each row.
Penny Nom lui répond.
A fixed point problem 2004-11-14
Bob pose la question :
I am trying to solve an existence of fixed point problem. I need to show that a function f (on reals) with f'(x)=>2 has a fixed point.
Claude Tardif lui répond.
An ODE 2004-11-10
David pose la question :
I have a question that i really cant do, it is as follows:

The ODE dy/dx + 0.5y = 0.5e^(-1.5x) ; y(5) = 2

Solve the ODE subject to the given condition using exact methods and evaluate the solution y for x = 5 x=5.2 x=5.4 x=5.6 x=5.8 x=6

Harley Weston lui répond.
Order of operations 2004-11-10
Andrew pose la question :
I'm trying to solve this question, and I can't seem to remember the rules back from my high school days.

(40 x 8 ) / 2 + 55 - 15 =

Can you help me with the answer?

Harley Weston lui répond.
A 40% reduction 2004-11-10
Cathy pose la question :
I'm having trouble figuring out how to figure a percentage??? it's easy to find what 40% of any given number is, but how would i accurately figure out what is the final number is when i know the number after the 40% has been removed? when i add 40% to this number it obviously is lower than it should be. the best i could figure is; x=?-40% ---------------> x-?=-40% i'm all confused????
Penny Nom lui répond.
Bedmas 2004-11-09
Fariha pose la question :
i have a single line question and am not sure of the method it would be appreciated if u could send me a method and a solution Q : 1 + 9 / 2 + 5 * 1000

would this be solved by BEDMAS? if not, why?

Penny Nom lui répond.
A standard deviation test 2004-11-09
Karen pose la question :
How do you compare to see if a sample standard deviation is different than the population standard deviation? I know how to compare means, but not standard deviations.
Penny Nom lui répond.
A 30-60-90 triangle 2004-11-09
Amy pose la question :
How do you find the length of the hypotenuse of a 30-60-90 triangle when the side opposite the 60 degree angle is 6 inches?
Penny Nom lui répond.
Factoring 2004-11-09
Rise pose la question :
Q1: a2 + 5a + 6

I didn't really understand the purpose of the teacher's steps, but was able to get my daughter to find factors of 6 and then add them together to find which resulted in the sum of 5.

Unfortunately, this problem-solving technique did not help us to solve for the more complex problems as follows:

Q2: 9a3 - 24a2 + 12a

Penny Nom lui répond.
The lcm of 5, 3, 4, 7 and 2 2004-11-05
Christine pose la question :
what is the lcm of 5,3,4,7,2
Penny Nom lui répond.
42.5 is what % of 170? 2004-11-05
Dawn pose la question :
42.5 is what % of 170?
Penny Nom lui répond.
The points of intersection of two graphs 2004-11-05
Benjamin pose la question :
How do I find the points of intersection of the two functions:
1) y =
2 - e-x 2) y = 1 + x2

Harley Weston lui répond.
Probabilities in poker 2004-11-04
Ben pose la question :
Please can someone tell me the odds of getting a royal flush while playing texas hold em.
Please can you also let us know the odds of a royal flush while playing texas hold em if you must be dealt two of the needed cards.

Chris Fisher lui répond.
The least common denominator 2004-11-03
A student pose la question :
Write the LCD for each pair of fractions.

13. 1/3,1/5

14. 2/7,1/4

15. 3/4,3/5

Penny Nom lui répond.
The lcm of 1 and -1 2004-11-03
Nayiyan pose la question :
I would like to know what is the LCM of (-1) and (+1) is.
Penny Nom lui répond.
Adding 3% to get 120,000 2004-11-02
Shaun pose la question :
I was asked a question by a friend of mine's kid. He asked me if you had a final figure of say 120,000, how do you work out the amount you started with if you added 3% of the starting amount, to the starting amount to get the 120,000.
Paul Betts lui répond.
Tennis balls and probability 2004-11-01
Jeremy pose la question :
I have a hopper of tennis balls that contains 25 new tennis balls and 10 old tennis balls. In the hopper the tennis balls are mixed up randomly. If i take one ball out of the hopper and hit it and then put it back and then take another ball out of the hopper and hit it and put it back, what is the probability that i hit two new tennis balls? Also a tennis ball becomes old after being hit just once.
Penny Nom lui répond.
The sides of a hexagon 2004-11-01
Timothy pose la question :
I have a perfect Hexagon in which i know the measurement across is 10m. Not from point to point, but from the middle of one side directly across to the middle of the other. From that measurement, how can I determine the length of 1 side.
Penny Nom lui répond.
Multiplying two algebraic fractions 2004-10-31
A parent pose la question :
Multiply:

x+2 x²-4
----- x -------
x-2 x²+x-2


Harley Weston lui répond.
Imaginary roots of a ploynomial 2004-10-31
Jennifer pose la question :
how to find the roots of a polynomial equation if it would be imaginary?
Harley Weston lui répond.
GCD and LCM 2004-10-31
Cartalina pose la question :
how do you calculate the "positive difference between the GCF and LCM of two numbers"?
Penny Nom lui répond.
The combined force of two vectors 2004-10-30
Brian pose la question :
Two teams are playing push ball with a large 8 foot diameter ball. One team exerts a force represented by the vector a = 2i + -5j, and the other team exerts a force represented by the vector b = -8i-3j.

1.Determine the direction of movement of the ball if the i axis is due east.

2.Determine the combined force magnitude.

Harley Weston lui répond.
Solving triangles 2004-10-30
Allen pose la question :
Solve the following triangles.

Given

1. B = 20 Degrees, a = 25, b = 16
2. A = 35 Degrees, b = 2, c = 3
3. A = 32 Degrees, C = 44, c = 20

Harley Weston lui répond.
Vectors in three space 2004-10-30
Jo pose la question :
I have two questions that I just cannot visulise and dont know how to get started on them..!

1. Ship X is sailing North at 4m/s and Ship Y is sailing due East at 3m/s. A sailor on Ship X climbs a vertical pole at 1/2 m/s. What is the velocity of the sailor on Ship X relative to an observer on Ship Y? State it's magnitude and direction.

Not sure where to start with this one...

2. Show, using vectors, that for any tetrahedron, the segments joining the midpoints of the opposite edges are concurrent. i know what a tetradedron is, and what I am proving but do I solve simultaneously for a specific case??

Walter Whiteley lui répond.
Bedmas 2004-10-30
Gina pose la question :
I am just curious whether Bedmas would be used in the following question as it is not in the typical Bedmas format.

Multiply 12 x 24
Add 26
Divide by 2
Subtract 7


Would we go about doing it in the sequence it is given or in Bedmas ?

Penny Nom lui répond.
The force of a 5000 tonne lorry 2004-10-27
Aaron pose la question :
A 50 tonne lorry is parked on a slope with a gradient of 4%. Due to the self weight of the lorry, what is the force

* acting down the slope
* acting normal (at right angles) to the slope

Penny Nom lui répond.
Ratios and rates 2004-10-27
Kenneth pose la question :
What is the difference between a ratio and a rate?
Penny Nom lui répond.
Cube roots 2004-10-26
A parent pose la question :
How do you solve the problem of finding the cubed root of (17 to the power of 3).
Can you show me each step and if you have a visual representation of this it would be very helpful.

Also can you show a step by step of finding the cubed root of 27. Visuals help a lot

Penny Nom lui répond.
20 Golfers 2004-10-26
Ian pose la question :
I have 20 golfers playing over 6 days I would like to schedule all 20 golfers in 5 groups of 4 on each day here is the catch.... I would like each player to play with each other once during the 6 days.
Chris Fisher lui répond.
The point slope form of a line 2004-10-26
Jack pose la question :
Given a set of ordered pairs, ie (1,1) (2,4) (3,7), how does one determine the rule f(n) other than by trial and error
Penny Nom lui répond.
Largest square inside a circle 2004-10-25
Bob pose la question :
my granddaughter asked
what is the largest size square in inches would fit in a 60 inch circle?
I believe it to be around 42.3 inches but would like to teach her how to do it mathematically.

Penny Nom lui répond.
Square roots and inequalities 2004-10-25
Waheed pose la question :
Q1. What is the simplest way of finding a square root of any number using just a pen and paper? (I am asking this question because I browsed a few sites a didn't find any method that is simpler than the one I use. so I am just curious.)

Q2. Is it possible that you take an equation and turn it into an inequality by performing same mathematical operations on both sides?

Claude Tardif and Penny Nom lui répond.
Converting coordinates 2004-10-25
Allen pose la question :
I am trying to help my son with his home, but I don't remember these conversions. Please help.

1. Convert the following coordinates Cartesian x = 7, y = -24

2. Convert the following coordinates Polar r = 4, theta = pi / 3

Penny Nom lui répond.
Implicit differentiation 2004-10-24
Emily pose la question :
If x^3+3xy+2y^3=17, then in terms of x and y, dy/dx =
Penny Nom lui répond.
Maximize income 2004-10-24
Connie pose la question :
A company that sells x units of a product generates an income (I, in dollars) which is a function of x. The income generated is described by the equation

I = (-1/2)x^2 + 100x.

Discuss how to determine the number of units that must be sold so that the company can maximize its income. What is the maximum income?

Penny Nom lui répond.
Practical applications: parabolas and Pythagoras 2004-10-24
Connie pose la question :
Provide two examples of real life objects that incorporate parabolic shapes. Explain the reason why the parabolic shape was used in each object.

I need at least one practical application of the Pythagorean Theorem.

Penny Nom lui répond.
Solve for a and t 2004-10-23
Justin pose la question :
How do I solve for "a" and "t" in the equations:

1000t= -4000 + 2000t + (1/2)at^2
1000=2000 + at

Penny Nom lui répond.
An aircraft is flying directly from airport A to airport B 2004-10-22
A student pose la question :
In this question, i is a unit vector due east and j is a unit vector due north. An aircraft is flying directly from airport A to airport B, which is 2000 km from A. The velocity in still air of the aircraft is (150i+50j)km/h and the ground speed is (200i-30j)km/h. Calculate

(i) the time of flight, to the nearest min
(ii) the direction of the wind.

Penny Nom lui répond.
The last digit of a large exponent 2004-10-20
Landon pose la question :
How can one determine the last digit of a large exponent by hand. I have seen several examples of how to do this by breaking it up into smaller exponents, but is there a formula or some common things to look for?
Penny Nom lui répond.
sin(3A) 2004-10-20
A student pose la question :
Express sin3A in terms of sinA and cosA.
Penny Nom lui répond.
A 40% increase in garage space 2004-10-20
Dianna pose la question :
A bus company recently expanded and no longer has enough room in its garage for all of its buses. Twelve of the buses have to be stored outside. If the company decides to increase their garage space by 40%, this will give them enough room for all of their current buses, plus enough room to store another twelve in the future. How many buses does the company own?
Penny Nom lui répond.
A square footage problem 2004-10-19
Jerome pose la question :
I have a peice of property that is almost a triangle but not exactly about 280 frontage with the side lines at 228 and 237

I was told I had about one acre plus a little, a developer says I have 33,000 sq ft. and I would like to know what the real result is

Penny Nom lui répond.
Manipulating exponents 2004-10-17
A student pose la question :
I was wondering if you can describe the steps in getting the solution to the problem below. I have the solution of 5/3 in the back of a book, but I have no idea how that answer was reached.

2raised to the 100th power + 2raised to the 98th power divided by 2raised to the 100th power - 2raised to the 98th power

Penny Nom lui répond.
The third derivative 2004-10-15
Holly pose la question :
Why would you ever take the third derivative?
Harley Weston lui répond.
A rate of change problem 2004-10-15
Frank pose la question :
Find the rate of change of the distance between the origin and a moving point on the graph of y = x(squared) + 1 if dx/dt = 2 centimeters per second.
Penny Nom lui répond.
Two gears 2004-10-14
Lindsay pose la question :
"There are two gears, a small one on the left and a larger one on the right. The gear on the right makes 1 revolution. The gear on the left makes two revolutions. Suppose the gear on the right is turned through an obtuse angle. Will the gear on the left make a full turn?"
Penny Nom lui répond.
Divisibility by 7 and 11 2004-10-13
Tammy pose la question :
I'm stuck in class in Yr 7 And I'm finding it hard on our new topic Divisibility! When I try to find out what this means on Internet sites i can not understand the used symbols like algebra and so on. I'm stuck on the divisibility rules for the number 11!
Penny lui répond.
$25,000 at 11% per year 2004-10-13
A student pose la question :
suppose u have $25,000 to invest and the interest rate at your bank is 11%. 1) how much money would you have at the end of EACH of the first four years? 1) i already kno that the first year w/ interest is $27,750 but how do i get the 2nd? 3rd? 4th? years?
Penny lui répond.
Pythagoras in everyday life 2004-10-13
Tiffany pose la question :
I was wondering if you have any real-life uses of the pythagorean theorem that you use in your everyday life.
Penny Nom lui répond.
Cycling in the wind 2004-10-11
A student pose la question :
A cyclist is travelling in the direction of 12i+5j at a speed of 39 km/h where i is a unit vector due east and j is a unit vector due north. The wind appears to the cyclist to be blowing with a velocity of (-4i+j) km/h. Find, correct to 1 d.p
(a) the true speed of the wind and
(b) the bearing from which the wind is blowing

Penny Nom lui répond.
An Octagon 2004-10-10
A parent pose la question :
I am trying to determine what the size of each triangle is of a 12 foot circle consisting of 8 triangles would be. I've gotten as far as the radius being 6 feet, but cannot figure the distance.
Penny Nom lui répond.
A five digit number 2004-10-06
A parent pose la question :
What is the 5 digit number in which the first 2 digits are the square of the 3rd digit and the last 2 digits are the square of the digit that is one less than the third digit? The sum of all the digits is 22.
Penny Nom lui répond.
A common tangent line 2004-10-05
Shanup pose la question :
The x-axis is a common tangent of y = x^2 and y = x^3. Find the equation of another common tangent.
Penny Nom lui répond.
Direct and inverse variation 2004-10-05
Abraham pose la question :
Given that y varies inversely as x and x varies directly as z.If z is doubled then y is halved.Why is that true.Please explain.I'm having trouble understanding the different types of variation
Penny Nom lui répond.
Accelerating to the speed of light 2004-09-30
Lars pose la question :
How long time would it take to accelerate up to the speed of light with an acceleration speed similar to 0-100 seconds in 5 seconds?
Penny Nom lui répond.
A mixture problem 2004-09-30
Abraham pose la question :
A chemist has one solution that is 35% pure acid and another solution that is 75% pure acid. How many cubic centimeters of each solution must be used to produce 80 cubic centimeters of solution that is 50% acid?
Penny Nom lui répond.
A theorem involving a trapezoid 2004-09-29
Abraham pose la question :
Given:Trapezoid ROSE with diagonals RS and EO intersecting at point M
Prove:Diagonals RS and EO do not bisect each other.

Harley Weston lui répond.
The area of a lot 2004-09-29
Deb pose la question :
I am trying to figure out how many square feet are in a piece of property. Start at Point A-then go 140 feet north-then 100 feet due east-then 300 feet at an angle southeast so that connecting to point A would be a straight line (right angle to first line north.)
Penny Nom lui répond.
Visitor wins or home wins 2004-09-29
Paavn and Laddi pose la question :
I have a math question i am stumped on for one of my classes. The question states that there are 14 baseball games with 2 possible outcomes for each game, visitor win or home win. How many different total combinations are possible from the 14 games?
Penny Nom lui répond.
Cubic yards of concrete 2004-09-29
Tanya pose la question :
We are starting up a new business and for the business we will be required to order concrete for various shapes. Right now we have a job that requires a concrete slab that a decagon it is 140-3/4" from flat side to flat side, 74" from point to center and each flat side is 46" The pad should be 4" thick with 12"x12" continuous footing.
Harley Weston lui répond.
The area of a lot 2004-09-28
Stan pose la question :
I own a parcel of land (lot 20) that is assessed at 9127.00 square feet and has a frontage of 99.90 feet according to the tax roll. I don't know how large my property actually is since I feel that the tax assessment and the survey map don't jive
Harley Weston lui répond.
A palindrome question 2004-09-28
Lilly pose la question :
12, 21, 13, and 31 are the only double-digit numbers whose squares are the palindromes of the squares of the palindromes of double-digit numbers. I was wondering why it works for these numbers, and if only these numbers work this way.
Chris Fisher and Penny Nom lui répond.
The length of a rectangle 2004-09-26
Rebecca pose la question :
My question is each side of a square S is 18 inches long and the area of S is at least 3 times the area of a rectangle that is 9 inches wide. What is the greatest possible length in inches of the rectangle?
Penny Nom lui répond.
37% 2004-09-26
Andrew pose la question :
how do we change 37% into a fraction
Penny Nom lui répond.
Grams to milliliters 2004-09-25
Emily pose la question :
I am trying to convert 19.5g into mL assuming that it's water; density=1g/mL. I don't know where to begin.
Penny Nom lui répond.
A parallelepiped 2004-09-25
Aman pose la question :
" If OA, OB, and OC are three edges of a parallelepiped where O is (0,0,0), A is (2,4,-2), B is (3,6,1), and C is (4,0,-1), find the coordinates of the other vertices of the parallelepiped.)"
Penny Nom lui répond.
The last digit of 2^28 2004-09-25
A student pose la question :
I am currently enrolled in a math reasoning class and a math question I have to answer is determine the units digit in 3 28power. When I set up a table and keep cubing the numbers, I find a pattern with the last digits of the numbers that follow 1,3,9,7. My calculator gets to about the 19th power, and then I get an error. If I continued the pattern, would the units digit then be the last digit of 3 28th power, which would be a 7? Please let me know if I am solving this correctly and what a unit's digit actually is.
Penny Nom lui répond.
Rational expressions 2004-09-24
A student pose la question :
In general, I understand rational expressions except when it comes to solving problems such as:

x+y/2x-y - 2x/y-2x or m-4/3m-4 + 3m+2/4-3m

I am confounded by the issue of having to find a common denominator. For example, if I tried to solve these problems by multiplying both denominators they would still be uncommon.

Claude Tardif lui répond.
Supplementary angles 2004-09-23
Rosemary pose la question :
Is the term supplementary angles only applicable to 2 angles (ie. a pair of angles) or can it be used when talking about 3 or more angles that add to make 180 degrees?
Penny Nom lui répond.
Incremental variance 2004-09-23
Carlos pose la question :
I must keep statistical data (mean and variance) in 3 granularity levels depending on the age of the data (daily for older than 1 year, hourly for older than 1 month and quarter-hour for older than 1 day). How can I calculate the resulting variance from a set of variances previously calculated supposing I have the count and mean for each member of the set?
Andrei Volodin and Penny Nom lui répond.
The volume of a pile of mulch 2004-09-22
Sam pose la question :
Is there a formula to determine the cubic feet of something in a pile. IE- I need to determine the cubic feet of a pile of mulch. The pile comes to a peak, so the length and width decrease as the pile increases.
Penny Nom lui répond.
Four and five digit numbers 2004-09-21
Josy pose la question :
The question I have now in front of me is....Is a 4-digit number always less than a 5-digit number? Hi Josy, The digits in order are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Thus the largest four digit number is 9999. The smallet 5 digit number is 10000. Penny Go to Math Central
Penny Nom lui répond.
1,3,6,11,18,29,__ 2004-09-21
Guillermo pose la question :
How do you get to the answer of this sequence 1,3,6,11,18,29,__
Claude Tardif lui répond.
f(x) = x-4 if x<2 2004-09-21
Dani pose la question :
Hi, my name is Dani. I'm in tenth grade Algebra 2, and I'm learning about a lot of different kinds of functions, and I can't quite seem to understand how every part of the piecewise function works. I understand most of it, I think, but I've been looking at an example in my math book, and I'm not sure how they got the answer they did. The part I don't understand reads: "Graph f(x) = x-4 if x<2" and "Identify the domain and range." The picture in the book shows an open circle at (2,-2), with an arrow going down and to the left with the slope being one. How did they get the open circle to be at (2,-2), and why does the arrow point where it does?
Penny Nom lui répond.
The method of substitution 2004-09-20
Kayla pose la question :
y=x-1
y=2x-3

Harley Weston lui répond.
Wages for one month 2004-09-20
Janet pose la question :
if offered $10,000 or 1 cent on the first day and then doubled daily for one month which would you take ?
Harley Weston lui répond.
B={A,{A}} 2004-09-20
Muhammad pose la question :
Let A be a set and let B = {A,{A}}.

(a) Explain the elements of set B (with some example)

(b) Prove that A is not a subset of B.

Penny lui répond.
The hypotenuse of a right triangle 2004-09-20
Shannon pose la question :
I am trying to find the hypotenuse of a right triangle with only the length of the opposite side. What is the formula as I don't have the length of the adjacent side? Can I compute it without knowing what the other two angles are?
Penny Nom lui répond.
Fabricating with pipe 2004-09-19
Gil pose la question :
I need to fabricate a 10 section, 4" pipe circle with an inside diameter of 40". I would like to know what angles would apply and how to find them,
Penny Nom lui répond.
A binomial squared 2004-09-19
John pose la question :
Can you explain the steps for me, that get you from (a - b)2 to a2 - 2ab + b2
Penny Nom lui répond.
Perimeter and area of a semi_circle 2004-09-18
A student pose la question :
I want to know how to find the perimeter and area of a semi-circle and a quarter-circle.
Penny Nom lui répond.
Zero to the zero 2004-09-18
Greta pose la question :
My name is Greta, and I am a 7th grader and my test is coming up. The question I would like to ask you is why 0 elevated to 0 is unidentified.
Penny lui répond.
Driving me crazy 2004-09-18
Jerry pose la question :
This is driving me crazy!!! Someone told me of a number that can be divided EQUALLY by each of the following individual numbers: 1,2,3,4,5,6,7,8,9. what is that number?
Penny lui répond.
The price of a book 2004-09-18
Dorly pose la question :
If the number of toonies required to buy a book is nine more than the number of five-dollar bills required to buy the same book, determine the cost of the book.
Penny lui répond.
A challenge 2004-09-17
Lasse pose la question :
xy
xx
xyx
xxx
xyxx


"x" and "y" each represents a number. Find out the system to make the next line

Penny Nom lui répond.
Some numbers less than 100 2004-09-17
Paul pose la question :
for how many numbers less than 100 is the digit in the ones place half the digit in the tens place?
Penny Nom lui répond.
Division with and without units 2004-09-17
Kenneth pose la question :
What does it indicate when the divisor has units (dollars) but not the dividend, as in 500/$10.00 or 500 is divided by $10.00? Are the units understood to be there? Does 500/$10.00 make sense?
Penny Nom lui répond.
The length of a cut 2004-09-17
Florita pose la question :
My daughhter, who is a 9th grader is attempting to cut a piece of wood after determining the length of the cut for the hypotenuse. These are the measures: a=4squared, b=6squared.

She determined that c should equal 52. But when she measured the actual piece to be cut, c measured 39.5 inches! Can you offer any insight as to what she is doing wrong? I have suggested that she may be working with an Acute rather than a Right angle . But she insists that it is a Right angle after using a "framing square".

Claude Tardif lui répond.
Pizza for Jack? 2004-09-16
Grace pose la question :
Jack is playing pool with Jim for $1 a game. He has only $2 and decides to play until he goes broke or has $5, at which point he will quit and go out for a pizza with Jim(Dutch treat). Jack knows from past experience that he beats Jim 60% of the time. What is the probability that Jack will get to eat pizza? Hints: Let A be the 6x6 matrix defined by A=[aij], where aij is the probability that Jack will have $(i-1)after one game is he starts with $(j-1). For example, a23 - .40 since there is a 40% probability that Jack will end up with $1 after a game is he starts the game with $2 (If Jack wins 605 of the time, he must lose 40% of the time). Also, for example, a52 = 0 since there is no way jack can have $4 after one game if he had $1 at the beginning of the game. Since Jack will stop if he goes broke or accumulates $5, a11 and a66 are both 1.

Let x0 = [0 0 1 0 0 0 ] transposed, which we interpret as saying that initially Jack has $2 with a probability 1. Then Ax0 will represent the porbability of each amount of money, $0-$5, after one game. What is the probability that Jack will be able to eat pizza by computing Akx0 for large k and finding a limiting value.

Penny Nom lui répond.
Volume 2004-09-16
Jonathan pose la question :
I have an area of 22ft x 43 ft, 6 inches high
Sq. ft..946
sq. yds...105.1

What is the cubic feet and cubic yards for this dimension.

Penny Nom lui répond.
S is between T and V 2004-09-16
Reuben pose la question :
S is between T and V. R is between S and T. T is between R and Q.
QV=18 QT=6 and TR = RS = SV Make a sketch and answer the following:

Find RS QS TS TV

Penny Nom lui répond.
The game of 24 2004-09-16
Angelica pose la question :
how can you make 24 out of 7,7,6,5?
Claude Tardif lui répond.
Finding the height of a triangle 2004-09-14
A student pose la question :
I have to calculate the height of a triangle. The base is 6 (units)say ab One of the top sides is 4 (units)say ca The other side is 2 (units) say cb I don't know the angles.

How to find the height?

Chris Fisher and Penny Nom lui répond.
The game of 24 2004-09-14
Alan pose la question :
I was playing that math 24 game and i cant get 21,14,2,2 to equal 24
Claude Tardif lui répond.
Crossword math puzzle 2004-09-14
Joyce and Tiffany pose la question :
The puzzle name was real number vocabulary and the question is (a number that divides evenly into another what is it?). (Space in between tic-marks on a number line).
Harley Weston lui répond.
Payment plus interest 2004-09-14
Penny pose la question :
Brian wants to borrow some money from Margaret.
After three years he is to pay X back plus one interest sum of 25%. If he is pays back a total of $3800, what was the original sum borrowed?

Penny Nom lui répond.
differentiate Y=X^X^X 2004-09-13
Kunle pose la question :
differentiate Y=X^X^X
Penny Nom lui répond.
Making a pyramid 2004-09-12
Jacob pose la question :
My name is Jacob and I am a 11th grade student trying to build a pyramid for a friend but I need a chart of some sort to show me the measurements (I learn better w\pictures) it is a square base with 18 in sides and I want the vertex to be 18in above the base I need to know as many measurements as you can give me.
Penny Nom lui répond.
A copper sphere 2004-09-12
Irfan pose la question :
The radius of a copper sphere is 3cm. If a wire of 0.4 diameter is drawn by melting it,what is the length of this wire?
Penny Nom lui répond.
Three word problems 2004-09-12
Adrian pose la question :

1. Increasing area of a field: Julia's soybean field is 3m longer than it is wide. To increase her production, she plans to increase her to increase both the length and width by 2m. If the new field is 46m2(2nd power) larger than the old field, then what are the dimensions of the old field?

2. Width of a Football Field: If the perimeter of a football field in the NFL including the end zones is 1040 ft and the field is 120 yd long, then what is the width of the field in feet?

3. Fencing dog pens Clint is constructing two adjacent rectangular dog pens. Each pen will be three times as long as it is wide, and the pens will share a common long side. If Clint has 65 ft of fencing, what are the dimensions of each pen?


Penny Nom lui répond.
Number combinations 2004-09-10
Angela pose la question :
I need the number of possible number combinations, both 3 and 4 digit, from 0-59

I know that 0-9 has 10000 combinations for 4 digits I also know that 0-9 has 1000 combinations for 3 digits

Perhaps you could explain an easier way to figure this out rather than writing all these numbers down??

Penny Nom lui répond.
A schedule for 6 teams 2004-09-10
Greg pose la question :
I have a schedule I need to make of 6 teams. They must play each other once however no team can be the away team twice in a row. There must be 3 home games and 3 away games for each team.
Penny Nom lui répond.
105.6 is a discount of 12% from x 2004-09-10
David pose la question :
If I know that 105.6 is a discount of 12% from x, how do I find x??
Penny Nom lui répond.
1+3+5+...+(2n+1) 2004-09-10
Emma pose la question :
Prove that 1+3+5+...+(2n+1)= (n+1)2
Penny Nom lui répond.
Safe cracker 2004-09-09
Adam pose la question :

Franklin's friend had taken an item from him, and put it in his family's safe, when franklin went to retrieve it he came to a combination lock on the safe, with the dial numbers going from 0 to 59. Unfortunately, he wasn't sure whether there were three or four numbers in the combination, or even which direction to turn the wheel

If it takes him 15 seconds to try a single combination, how many days will it take him to to try every possible combination? Please round to the nearest day.
Penny Nom lui répond.

The 24 game 2004-09-09
Erik pose la question :
Ive spent around 40 hours on this one problem. I need help. 3,3,7,7
Claide Tardif lui répond.
A travelling salesman 2004-09-09
Liz pose la question :
A salesman traveled due west from city A to city B. The distance he traveled, that is the ditance from A to B, was X miles. He returned from B to A and found that he had traveled half the distance, X/2 miles. How can that be?
Chris Fisher and Penny Nom lui répond.
Crossing a river 2004-09-09
Barb pose la question :
Nine men and two boys, trekking through the jungle, need to cross a river. They have a small inflatable boat and it's easy enough to row it across the river. The boat, however, can hold no more than one man or the two boys. How can they all get across? (Hint. suppose there was only one man and two boys) Does it make math sense and what would the answer be
Penny Nom and Claude Tardif lui répond.
An inverse 2004-09-09
Hillary pose la question :
I cannot figure out the inverse of this function.
f(x)= 1/2x -1

Penny Nom lui répond.
Half way between 2004-09-08
Ben pose la question :
Find the number halfway between the number shown

751,843

Penny Nom lui répond.
The nth term 2004-09-08
Alex pose la question :
What is the nth term?... Like what is it?, How do I find it?, and how exactly is used?...
Penny Nom lui répond.
d varies inversely with g 2004-09-07
Ashlyn pose la question :
d varies inversely with g when d=-8 and g=2 a. write d as a function of g using function notation. b. find d(10).
Penny Nom lui répond.
Constructing a cone 2004-09-07
Steve pose la question :
I am trying to build crayfish traps; one of the components is a cone shaped entry section.

The cone I want to make would be 12" in diameter at the base and 12" in height, from base to peak.

I need a formula to calculate the dimensions and a method of transferring the shape onto a flat piece of material.
Harley Weston lui répond.

The intersection of planes 2004-09-07
Joshua pose la question :
I was wondering about the intersection of planes. Can planes intersect?
Penny Nom lui répond.
The bar over repeating digits. 2004-09-07
Debbie pose la question :
I would like to know the name given to the bar that is written over the repeating digits of a decimal.
Penny Nom lui répond.
How to dry matches 2004-09-06
Liz pose la question :
The neighbors of a young man who needed seclusion for a few days offered him the keys to their cabin in Maine. Arriving there on a damp and cold autumn evening he saw that while the cabin had normal running water and electric lights, for heat it had only a pot-bellied stove. Fortunately, there was plenty of wood, kindling, newspaper, and matches. Being an experienced hand at making a fire, he opened the damper, put into the stove crumpled newspaper, and properly stacked the kindling and logs. The matches, however, wouldn't light. They were too damp from the humidty. The nearest town was 30 miles away, and, anyway, it was late. What next?
Claude Tardif lui répond.
(2x+5y-6) + (3x-4y+12) 2004-09-04
GG pose la question :
I am a grade 9 student and i do not understand a question. Plz help! OK here it is........ (2x+5y-6) + (3x-4y+12)
Penny Nom lui répond.
Order of operations 2004-09-04
Leanne pose la question :
6 + 3 - 2 x 3 =
Claude Tardif lui répond.
The distance formula 2004-09-04
Joe pose la question :
Why do we use square roots and squares in the distance formula Wholdnt they cancel each other out?
Claude Tardif lui répond.
Nine minutes 2004-09-02
A student pose la question :
You have two hour glasses-one measures 7 minutes and one measures 4 minutes.How can you time 9 minutes?
Penny Nom lui répond.
Cubic yards 2004-09-01
Garnet pose la question :
I have the dimensions of 16 feet by 10 ft and 3 1/2 inches deep how much concrete do I need.
Penny Nom lui répond.
An isosceles trapezoid 2004-08-31
Bruce pose la question :
An isosceles trapezoid with bases of lengths 12 and 16 is inscribed in a circle with a radius of 10. The center of the circle lies in the interior of the trapezoid. Find the area of the trapezoid.
Penny Nom lui répond.
Cubic meters 2004-08-31
Brad pose la question :
I have a 10' x 10' x 12" area & need to find the cubic meters, how do I do this?
Penny Nom lui répond.
Percentage change 2004-08-30
Lauren pose la question :
if egg A weighed 55.4g and after 2 days it weighed 60.9g how could i calculate the percentage change in weight?
Penny Nom lui répond.
Solve for z 2004-08-30
Ana pose la question :
Solve for z when 4x + 10yz = 0

solve for z if y2 + 3yz - 8z - 4x = 0?

Do I have to solve all of the variables in order to get z?

Penny Nom lui répond.
69 is what percentage of 113 2004-08-28
Mary pose la question :
How do I work out what percentage of 113 69 is?
Penny Nom lui répond.
GCD (a + b , a^2 - ab + b^2) 2004-08-27
Carol pose la question :
Let a and b integer and relatively prime. Proof that:
GCD (a + b , a^2 - ab + b^2) = 1 or 3

Penny Nom lui répond.
A big number 2004-08-26
Mark pose la question :
If you have $999,999,999,999,999,999,999,999,999,999.99 and you find a pennie how much is that and can you give me the name of it.
Penny Nom lui répond.
Combined operations 2004-08-26
Louise pose la question :
Question 2 1/4 x 1/8 / 1 3/4 x 12 4/9 x 3 =
Penny Nom lui répond.
Percentage of a quota 2004-08-26
Jenni pose la question :
I have the year to date sales of $2,042,744 and the quota is $2,257,440, how do I figure the percent quota.
Penny Nom lui répond.
The area of a quadrilateral 2004-08-25
Rich pose la question :
I would like to know how to measure the area (the formula) of a quadrilateral.
Penny Nom lui répond.
The radius of a circle 2004-08-24
Peter pose la question :
If you slice any circle with a line, and call the distance of the line between intersections the "y" length and the perpendicular length to the shorter side of the curve the "x" length, what is the resulting equation for the radius?
Penny Nom lui répond.
50/5x - y 2004-08-22
Rick pose la question :
Niece has a question that was marked wrong but we are unable to determine how the teacher calculated and arrived at the answer? The problem was as follows:
50 / 5x - y =

x=5
y=1

Harley Weston and Leeanne Boehm lui répond.
The area of a lot 2004-08-22
Cassie pose la question :
I'm in the process of purchasing some land and I'm trying to figure out the square footage of the property. Unfortunately, it's be a while since I had to remember this type of formula. The property is 140 ft on left side, across the back it is 220.61 ft, the right side is 167.52 ft, the frontage is 105 ft.
Penny Nom lui répond.
15 cubic yards of dirt 2004-08-22
Barry pose la question :
My question...what is the equivalent of 15 cubic yards of dirt?
Penny Nom lui répond.
130 cc. is ? 2004-08-20
Ayrn pose la question :
130 cc. is ? I have to put 130cc. of petroleum in a bucket how much exactly is that? Also 110 cc.? I have to also put 110cc. wood alcohol in a bucket aswell!
Penny Nom lui répond.
Golfing with Norm 2004-08-19
Norm pose la question :
I am organizing a golf tournament with 6 American and 6 Canadian players. We play 3 rounds of golf. Is there any way to arrange that everyone plays without playing with the same person twice. Each foursome must consist of 2 Americans and 2 Canadians with one of each in a cart. Your help would be much appreciated.
Claude Tardif lui répond.
Golfing with Sally 2004-08-19
Sally pose la question :
We are a group of 8 golfers (2 foursomes) and want to golf 3 games together. How can we arrange it so that we all get to golf with each other at least once?

At another venue, we have 18 golfers (3 foursomes, 2 threesomes) and want to golf 6 games together. Same question, how can we arrange it so that we all get to golf with each other at least once?

Claude Tardif lui répond.
A division symbol 2004-08-18
William pose la question :
i was wondering what the mathematical name for this division sign (÷).
Penny Nom lui répond.
A cube is inscribed inside a sphere 2004-08-18
A student pose la question :
A cube is inscribed inside a sphere with radius sqrt8cm. Find the
(a) length of the cube
(b) volume of the space inside the sphere but outside the cube.

Penny Nom lui répond.
The series from i=1 to n :ai 2004-08-18
Ken pose la question :
a.) Explain the difference between
the series from i=1 to n :ai
and the series j=1 to n :aj


b.) Explain the difference between
the series from i=1 to n:ai
and the series from i=1 to n :aj

Penny Nom lui répond.
Area of a triangle 2004-08-17
Barkie pose la question :
I'm going into tenth grade and I have a triangle who's sides measure 3ft, 4ft, and 5ft. I need to find the area however I don't know the height, or how to get it.
Chris Fisher lui répond.
Two water jugs 2004-08-16
A student pose la question :
You go to a source of water with two jugs and only two jugs. One jug has a capacity of exactly three pints and the other five pints. Both jugs are opaque (you can`t see inside them) and irregularly shaped. You have no other water containers. You do not have a scale. How can you use the two jugs and only the two jugs to measure exactly four pints of water?
Penny Nom lui répond.
Percentiles 2004-08-15
Gary pose la question :
Table 1 Selected percentiles for family income in the US in 1992 1 $1,300 10 $10,200 25 $20,100 50 $36,800 75 $58,100 90 $85,000 99 $151,800

Q. The percentage of families in Table 1 with incomes below $58,100 was about?

Penny Nom lui répond.
A probability question 2004-08-15
Gary pose la question :
In a law school class, the entering students averaged about 160 on the last LSAT; the standard deviation was about 8. The historgram of the lLSAT scores follwed the normal curve reasonable well.

Q. About what percentage of the class scored below 166?

Q. One student was 0.5 above average on the last LSAT, about what percentage of the students had lower scores than he did?

Penny Nom lui répond.
X is due north of Y ... 2004-08-11
A student pose la question :
X is due north of Y and 2km distant. Z is due east of Y and has a bearing of S35°12'E from X. How far, to the nearest metre, is Z from X?
Penny Nom lui répond.
Cubic yards of dirt 2004-08-11
A parent pose la question :
How many cubic yards of dirt would it take to fill an area that is 325 feet by 325 feet and is 3 feet deep?
Penny Nom lui répond.
Acres and miles 2004-08-11
A student pose la question :
How many acres are in 1 mile?
Penny Nom lui répond.
2.79 acres 2004-08-11
Helen pose la question :
What would the square footage be of 2.79 acres?
Penny Nom lui répond.
Area of a hexagon 2004-08-10
RB pose la question :
Hello. I need to find the Area in sq. ft. of a Hexagon with 6 equal sides, of 26' each.
Penny Nom lui répond.
A conic 2004-08-10
A student pose la question :
My question is about this equation 32x*2 -18y*2 -64x +72y +248 =0 explain why as x goes to the infinity the graph of the conic looks like y= (3/4)X.

What I did to try to find the solution of this problem was to graph and then I thought that maybe trying to find the equation of the asymptotes I could do it, but it was useless -because the equation of the asymptotes is y= +4/3(X-1) -2 and that does not explain why tho conic looks like y=(3/4) x . I would really appreciate your help on this.

Penny Nom lui répond.
Constructing a triangle 2004-08-08
KV pose la question :
HOW TO CONSTRUCT A TRIANGLE ABC, WHEN ITS ALTITUDES AD,BE,CF ARE GIVEN
Chris Fisher lui répond.
A big number 2004-08-08
Carter pose la question :
Can you tell me what number this is?
10,000,000,000,000,000,000,000,000,000,000,000,000

Where can I find the names for big numbers?

Penny Nom lui répond.
Limits and composite functions 2004-08-07
Sue pose la question :
I have two questions, one about a limit and the other about a composite function. If you could help me, I'd really appreciate it.

1. Find the limit:

lim[x->0] (x*csc(x))

I converted csc(x) to cos(x)/sin(x), but I didn't know what to do after that.

2. f(g(x)) = ln(x^2 + 4), f(x) = ln(x^2) and g(x) > 0 for all real x, find g(x):

I'm having trouble with this one because x^2 + 4 isn't a perfect square.

--Sue

Penny Nom lui répond.
The integrating factor method 2004-08-05
A student pose la question :
Whilst using the integrating factor method, I am required to integrate a function multipled by another function.

say f(t) = exp(kt) and some other function g(t); where exp = exponential and k is some constant.

Integral f(t)*g(t) dt or Integral exp(kt)*g(t) dt

What would the result of this integral be? I have never met an integral like this before. Would it simply be exp(kt)*g(t)/k? More specifically, the problem and my attempted answer is in PDF format:

In my attempted solution, I am unsure about the last two lines I have written out, as it relates to integrating a function multipled by another function.

Harley Weston lui répond.
Integrating e^sin(x) 2004-08-04
A student pose la question :
I need to know that how to solve the integral " e^sin x",
Harley Weston lui répond.
Differentiation 2004-08-04
A parent pose la question :
I am a parent trying to understand higher level of maths and would be very grateful if you could help with differentiating the following functions, identifying general rules of calculus:

a) f(x)=e^2^xIn(cos(8x))

b) f(x)=secx/SQRTx^4+1

Penny Nom lui répond.
Two trig problems 2004-08-04
Tracie pose la question :
sin^2x - sin x -12 = 0

sin 2x = -sin x

Penny Nom lui répond.
When is the limit of f(x) undefined? 2004-08-03
Nicolasa pose la question :
When is the limit of f(x) undefined?
Penny Nom lui répond.
an integer with three factors 2004-08-03
A student pose la question :
What is the probability that a randomly chosen 3 digit number has exactly 3 factors
Penny Nom lui répond.
sin^2x-5sinx-3=0 2004-08-02
Kerri pose la question :
hey my name is kerri i'm a college students and i was wondering if you could help in with this problems

sin^2x-5sinx-3=0

Penny Nom lui répond.
A tangent to a hyperbola 2004-08-02
A student pose la question :
The equation of a hyperbola is 32x*2 -18Y*2-64x +72y +248=0. The equation of a tangent line to this hyperbola is y= (16/15)X + 10/3 I have been trying to find the point where this line intersects the graph. What I did was solve for x and then plugged in the result into the equation of the hyperbola, but I am getting two answers and I am supposed to get only one because the line is tangent to the graph. For this reason, I would like to know what I am doing wrong or what I have to do to know which answer is correct.
Penny Nom lui répond.
Two problems 2004-08-02
JJ pose la question :
A question on my homework assignment about logs says "suppose that x=logA and y=logB & write the expression in terms of x and y"

log(A - B)

Is this even possible? It seems like a typo.

Another is: "solve for t."

12(1.221)^t = t + 3

Is this one possible? If it is, I cant figure it out.

Penny Nom lui répond.
A trig problem 2004-08-02
A student pose la question :
Given that the maximum value of [sin(3y-2)]^2 -[cos(3y-2)]^2 is k. If y>7, Find the minimum value of y for which [Sin(3y-2)]^2 - [cos(3y-2)]^2 =k.
Penny Nom lui répond.
Domain and range 2004-08-01
JJ pose la question :
I'm checking domain and ranges of these functions. Are these right?
Penny Nom lui répond.
The law of sines 2004-08-01
Joy pose la question :
How do you solve this? Do you solve this triangle using the law of sines of the law of cosines? (ASA)

A=120DEG. B=40DEG c=35 cm I keep getting different answers.

Penny Nom lui répond.
Rate of change problems 2004-08-01
Jim pose la question :
I just want to check a couple average rate of change problems because i just guessed on how to do them. Can you tell me how to do them?

the question says if f(x) = sqrt(x + 3), find f( x + rx). I got sqrt( x + rx + 3)

the other two are : f(x)= 3x-1 (f(x) - f(1)) / (x-1) ... I GOT 3 &

f(x)= x^3 - x (f(x) - f(1)) / (x-1) ... I GOT x^2 + x

Penny Nom lui répond.
Combien de litre y a t'il dans un M3 2004-07-30
Un eleve pose la question :
j'aimerais savoir combien de litre y a t'il dans un M3. car je dois mettre un produit spécial dans une piscine.
Claude Tardif lui répond.
A parallelogram 2004-07-30
Keith pose la question :
I'm a high school student and have been having trouble with this problem , which is based on one pair of parallel sides of a parallelogram: If AD = 6x-5 and BC = 3x+7 find x. Of course both sides have to be equal. Now I know the value of x is 4 So my question is how do you get 4 from the given information.
Penny Nom lui répond.
Extraneous solutions 2004-07-28
Nicole pose la question :
When I have a problem like (2x + 3)/5 = (x + 1)/6 and the question asks to check for extraneous solutions, how do you solve that?
Penny Nom lui répond.
Water in a cone 2004-07-28
A student pose la question :
A vertically inverted cone( i.e. vertex down) has a radius 7 inches and height 24 inches. Water is filled to one third of its height .Find the ht of water when cone is turned upside down
Penny Nom lui répond.
The third side of a triangle 2004-07-28
Annette pose la question :
How do you find the length of a triangle side if you know two sides?
Penny Nom lui répond.
Factoring 2004-07-28
Nicole pose la question :
Can 4x2 + 19x + 12 be factored? i have tried but i cannot figure it out. Is there a way to find out if it cannot be factored before i try to work out the problem?
Penny Nom lui répond.
The intersection of two graphs 2004-07-28
JJ pose la question :
Is there a way to find the intersections of these graphs algebraically?

x^2 + y = 4 & 2x - y = 1

I got (1.45, 1.9) and (-3.45, -7.9) with a graphing calculator.

AND THESE...

y = 3.29x & y = 5.5(x^0.5)+ 10000

I got x at 3133 with a graphing calculator.

Penny Nom lui répond.
x^2 = x + 2 2004-07-26
A parent pose la question :
x2 = x+2

My daughter came home with this equation today and although I know the answer is x=2, i have no way of proving it by showing any working out.

Penny Nom lui répond.
The railing around a pool 2004-07-26
Bob pose la question :
I have a 15' circular above ground pool. Around the perimeter of the pool are eleven (11) sections of railing. Each rail has 5 slots at each end for pins. I have calculated that the length of the arc under the railing to be 51.4". what I am trying to determine is the distance between the end points of the arc so that I can figure out which slot to use in the rails without going round and round the pool moving and removing the rails until they finally fit. Been there, done that, no fun.
Penny Nom lui répond.
The p-value 2004-07-25
Kathy pose la question :
Ms. Lisa Monnin is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.

At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the p-value?

Having problems finding the p-value & unsure of the formula. Kathy

Penny Nom lui répond.
Row echelon form 2004-07-24
Michael pose la question :
My name is Michael and I'm in the 11th grade. I have a Math question that I can't solve. The problem is system of equations that I need to do in augmented matrix form, find the row echelon form, and solve it by using back substitution.

2x + 3y + 7z =13
3x + 2y - 5z = -22
5x+ 7y - 3z = -28

Penny Nom lui répond.
The inverse of a quintic function 2004-07-22
A student pose la question :
I'm really having trouble finding out the inverse of this quintic equation. F(X)= X5+3X3+1.I know that this quintic has an inverse because it is one to one. But I can't find a method to solve this. Finding the inverse of a quadratic or a cubic equation is a lot easier, but with this quintc I am really lost. I even know how the graph of this equation and its inverse looks like, but I'm not sure if Iam getting the right equation. Please help me out.
Penny Nom lui répond.
Factoring 2004-07-19
A student pose la question :
Factor completely:
3x3 - 24y3
54x6 + 16y3
16xy - 4x - 4y - 1
0.09x2 - 0.16y2

Penny Nom lui répond.
The number of blocks in a mile 2004-07-18
Valerie pose la question :
I don't know if you can help me but I was wondering how many blocks are in a mile in Ocean City, New Jersey?
Penny Nom lui répond.
A proof in geometry 2004-07-16
An pose la question :
Im taking a geometry course for the summer , and we just started to learn about proofs for about one week. Today in class, we started to do this one proof but didnt finish it because class ended. the problem is as follows.
Penny Nom lui répond.
Solving some quadratic equations 2004-07-15
A student pose la question :
Could you please solve the following for x

x2+6=5x
x2+16=8x
2x+21=3x2

Penny Nom lui répond.
Two vector problems 2004-07-14
Jaye pose la question :
Two force, 120lb and 200lb, act on a body and make a 52 degree angle w/ ea. other. What's the magnitude of the resultant of the forces and what is the measure, to the nearest degree, of the angle that it makes with the 200lb force?
Penny Nom lui répond.
The commuter 2004-07-14
JJ pose la question :
A student who commutes 27 mi. to college remembers, after driving a few minutes, he forgot a term paper. Driving faster than usual, he returns home, gets the paper, and once again starts to school. Sketch the graph of the student's distance from home as a function of time.

Does it mean that the student drives at normal speed, drives faster to pick up the paper, and resumes normal speed to head back, or that the student drives at normal speed, then drives faster the rest of the way to college?

Penny Nom lui répond.
12(1.221)^t = t + 3 2004-07-14
Jay pose la question :
This problem has me stumped since i cannot separate the t and the 3. Here it is:

12(1.221)t = t + 3

It's on a logarithm worksheet, but how do i figure it out?!

Harley Weston lui répond.
Two puzzles 2004-07-13
Fred pose la question :
A young man's car developed a flat tire while he was driving along a deserted street. He pulled over to the curb and did all the usual things; removed the hub cap; unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them rolled down a nearby grate. Peering through the bars of the grate the man thought he could see the lugs about 6 feet below in a shallow water puddle. He had a problem, how do you think he solved it?

It is noon, your lunch hour, but you can not go out because there is a terrific hailstorm. Turning on your radio you hear the weathercaster predict that the hail will change to rain and that it will pour all day today. How can you determine the sun will be shining in 36 hours? Justify your answer.

Penny Nom lui répond.
An Octagonal playhouse 2004-07-13
Levi pose la question :
I'm building an octagon playhouse for my son that is 8 feet wide. what would be the measurements of each of the eight sides.
Harley Weston lui répond.
Cubic yards 2004-07-12
A homeowner pose la question :
I would like to know how many cubic yards are in the following; 20 ft wide x 80 ft long x 4 inches thick?
I am trying to figure out how much concrete I will need to pour for a driveway.

Penny Nom lui répond.
x = 2^x 2004-07-12
A student pose la question :
If the graphs of y=x and y=2x are drawn on the same set of axes, they will intersect when x is equal to what?

(1)1
(2)2
(3)0
(4)They won't intersect.

I know the answer is number 4 by graphing which is permitted; however, I would like to know if there is any algebraic way to do this type of problem.If yes, please show me how.Thanks.

Penny Nom lui répond.
Two Problems 2004-07-12
Justina pose la question :
i cant figure out the range of this equation in interval form because the highest point seems to be a decimal. please help f(x) = x + sqrt(4-x2)

.............................................................................

Building Design A circular air duct of diameter D is fit firmly into the right-angle corner where a basement wall meets the floor (see figure). Find the diameter of the largest water pipe that can be run in the right-angle corner behind the air duct.

Claude Tardif and Penny Nom lui répond.
The tangent of theta 2004-07-10
Jacob pose la question :
P is a point on a unit circle with coordinates(0.6,0.8). Find tan of theta. My book shows me how to do it,"tan of theta=opp./adj.=0.8/0.6=4/3,"and leaves it as that's the answer(4/3).When do we know from a problem to find the angle measure (in this case, the angle measure of theta) and how do we know when to give something like 4/3 without converting it to the angle measure?
Penny Nom lui répond.
Four digits 2004-07-10
Rob pose la question :
I am always interested to know how the for digit works. I mean, you have correctly put it that the total numbers obtain from 0000 thru 9999 are 10,000. My question is, is there any simple formula to turn this simple 4 figures of say: 1234.
Penny Nom lui répond.
The circle through three points 2004-07-06
Jim pose la question :
I am a student trying to solve math problem. I'd like to calculate the radius of the circle that exactly fits any three points. If the points are (X1,Y1), (X2,Y2), and (X3,Y3), what is the radius of the circle that contains those three points?
Penny Nom lui répond.
Vectors 2004-07-06
Annie pose la question :
a=3i-j+2k and b=i+3j-2k, determine the magnitude and direction cosines of the product vector and show that it is perpendicular to a vector c=9i+2j+2k.
Chris Fisher lui répond.
An ineqlality with absolute values 2004-07-05
Uneeza pose la question :
abs(x2 - 4x) > 3
Claude Tardif lui répond.
Factoring integers 2004-07-02
A student pose la question :
After looking at all the info I could get about NFS, I still have some questions that are unsolved:

First of all: If someone found an algorithm that has a worst case running time of N*Log(N) to factor an integer n into his divisors, would it be quicker or slower then the number field sieve algorithm?

secondly, what exactly is the time complexity of the Number Field Sieve algorithm, if I would factor an integer n?

Claude Tardif lui répond.
Choosing 5 numbers from 1,...,36 2004-06-30
A lottery player? pose la question :
how many combinations are there for the numbers 1thru 36 when only using each number once in groups of five
Penny Nom lui répond.
Simplify 2004-06-27
Tiff pose la question :
Simplify:

-3x (x2 + 2)

(x + 2) (x + 3)

Penny Nom lui répond.
Aunt Lucy's letter 2004-06-27
Olivia pose la question :
"Dear bob, now that i am getting on (70 today). i want to give you some of my money, i shall give you a sum each year, starting now. you can choose which of the following schemes you would like me to use.

a) £100 now, £90 next year,£80 the yaer after and so on.
b) £10 now, £20 next year, £ 30 the next year and so on.
c) £10 now, 1.5 times as much next year, 1.5 times as much the year after that and so on.
d)£1 now, £2 next year, £ 4 the year after, £8 the year after and so on.

of course these schemes will only operate while i am alive. i look forward to hearing which scheme you choose and why! Best wishes, Aunt Lucy."

Penny Nom and Claude Tardif lui répond.
Undercapatalized small businesses 2004-06-26
Greg pose la question :
Suppose that 30% of all small businesses are undercapitalized. 40% of all undercapitalized small businesses fail and 20% of all small businesses that are not undercapitalized fail. A small business is chosen at random. The probability that the small business succeeds if it is undercapitalized is? Greg
Penny Nom lui répond.
Pick a number greater than 1 2004-06-25
A student pose la question :
I understand that when you pick a number greater than 1 and less than 10; multiply it by 7 and add 23, then add the digits of that number until you get a one digit number. Then multiply that number by 9, add the digits of that number until you get a one digit number, subtract 3 from that number and divide the difference by 3; that this process will always give you the result of 2. Does this have a name or theory for it as to why the answer will always be 2?
Penny Nom lui répond.
(a+b) + 5i = 9 + ai 2004-06-25
Josh pose la question :
The question which someone gave you (a+b) + 5i = 9 + ai question) gave me trouble.
Penny Nom lui répond.
(ln(50/x)) / (ln(40/x)) = a 2004-06-21
Un eleve pose la question :
(ln(50/x)) / (ln(40/x)) = a = constante

comment extraire la variable x ???

Claude Tardif lui répond.
How much loam to fill a hole? 2004-06-19
Harry pose la question :
Can you tell me how much loam I would need to fill a hole 15 feet in dia. x 6 inches deep.
Penny Nom lui répond.
The surface area of a pyramid 2004-06-19
Jason pose la question :
I was wondering how to find the area of a pyramid when you donít know the height of the face but the height of the Pyramids highest point?
Penny Nom lui répond.
Forty balls are placed in a bag 2004-06-19
Sheila pose la question :
Forty balls numbered 1-10 are placed in a bag and four are drawn at random. What is the probability that the first ball drawn is between 1-10 (inclusive) the second is between 11-20, the third is between 21-30 and the last is between 31-40?
Penny Nom lui répond.
3+4i abd |3+4i| 2004-06-17
Sandy pose la question :
how would you do a question like |3+4i|? is that different than just doing 3+4i?
Penny Nom lui répond.
An equation with rational terms 2004-06-17
Louise pose la question :
simplify the expression (a2+n2)/2n = a2 + (a2-n2)/2n
Penny Nom lui répond.
Area of a lot 2004-06-17
Mike pose la question :
Could you please figure out the square footage and acreage of my lot? One side is 228 feet, another is 150 feet, another is 80 feet, and the last side is 164 feet. My house is in the middle and it is 62 feet by 37 feet. Is that subtracted from the total? I would like to know this when I have to buy fertilizer.
Penny Nom lui répond.
A garden space 2004-06-16
Carol pose la question :
We have a 17' x 19' garden space. If we want it a foot high raised bed, how many cubic yards of topsoil do we need?
Penny Nom lui répond.
The height of a building 2004-06-16
Lauren pose la question :
I have a homework assignment to measure a building on my school's campus. I have to stand at least 40 ft away from the building and find the angle of elevation from my feet to the top of the building. Then I have to walk at least 40 ft form that point, record the distance as X, and find the angle of elevation from my feet to the top of the building. Using X and the angles, I have to determine the height of the building. I used a protractor and a weighted string to find the angle of elevation from my eyes to the top of the building. But I haven't been able to find the way to measure the angle of elevation from my feet to the top.
Penny Nom lui répond.
Solving an equation 2004-06-14
Anthony pose la question :
I was hoping that you could help me with this problem. I believe that this is a high school level problem but as an adult who has forgotten the "rules", I am stuck.

the equation is this: x=t2/(t1-t2)

we know that x=5.73
t1=303

we must solve for t2

Penny Nom lui répond.
The Number of the Beast 2004-06-13
A Heinlein reader pose la question :
Most people who have an interest in mathmatics are familiar with Robert Heinlein's novel "The Number of the Beast", where 666, or ((6 to the 6th power) to the 6th power) equals 1.0315 times 10 to the 28th power, which in the novel is the number of parallel universes in the cosmos. My question is what would the number of parallel universes be if you grouped 666 the other way: (6 to the power of (6 to 6th power)). I have tried this on my calculator, but it won"t register that high.
Penny Nom lui répond.
Integers 2004-06-10
A parent pose la question :
I have an odd 3 digit product. My factors are a 1-digit number and either or 2- or 3-digit number. My factors are odd, but neither is 1. Find my factors and my product.
There is one answer. What is it?

Penny Nom lui répond.
Choosing an investment 2004-06-09
Max pose la question :
Let's say I have a list of different possible investements, and the list shows me my cost, and how much each investment will sell for.

In order to compare the investments and put them in order of relative profitability, I would want to sort them by their profits as percentages of what? Also, if each investment had an equal probability

of losing exactly 10% of the sell price before I sold would that have any relevance to the way I would calculate it?

Walter Whiteley lui répond.
Jack's social security number 2004-06-08
A student pose la question :
Jack's social security number contains each of the nonzero digits exactly once. By examining the digits from left to right, he also found that 1 divides the first digit evenly, 2 divides the sum of the first two digirs evenly, 3 divides the sum of the first three digits evenly, and so on, until 9 divides the sum of all the digits evenly. What is Jack's social security number?
Penny Nom lui répond.
The sum of some positive integers 2004-06-07
A student pose la question :
Find the sum of all positive integers not greater than 10000 that are divisible by neither 3 nor 7.
Penny Nom lui répond.
What is the name of a 3D rectangle? 2004-06-07
Jack pose la question :
if a cube is a 3D square, what is the name of a 3D rectangle?
Penny Nom lui répond.
The area of a pentagon 2004-06-06
Dana pose la question :
HELLO, I NEED HELP IN DETERMINING THE SIZE OF A PENTAGON.

one side is 280',from both ends of the 280 'section,we have 300' lengths,from one of these 300' sections we have a 118' length,which goes over to a length of 228',will this be enough info. or should i provide more. thanks

Penny Nom lui répond.
Percentage markup 2004-06-04
A parent pose la question :
if our cost is 54.00 and their cost is 117.00 what is the percentage of mark up?
Penny Nom lui répond.
A tangent to a quadratic 2004-06-04
Jem pose la question :
I have a question on the tangent to a quadratic curve. Say I have a curve y = ax2 + bx + c. The gradient, using the derivative of y, at any point x on the curve is: 2ax + b right? Then, for the tangent that cuts the curve at a point x, the equation of the tangent can be: y1 = (2ax + b)x1 + d.

My question is, how is the point d of this tangent determined? It is the point on the y-axis where the tangent cuts isn't it? Is there a formula for it?

Penny Nom lui répond.
The game of 24 2004-06-04
Samantha pose la question :
i have the game 24 (the one where you have to use multiplication, division, addition, and subtraction to get to the answer 24) I was playing when i came across the 4 numbers 20, 17, 7, 11 and i cant seem to get 24.
Claude Tardif lui répond.
Divisors of 2n+1 and 3n+9 2004-06-02
Chris pose la question :
Amy selected a positive integer N and wrote numbers 2xN+1 and 3xN+9 on a whiteboard. Boris looked at the two numbers on the whiteboard and wrote in his notebook a positive integer that divides each of them. Find all possible numbers that Boris could have written in his notebook.
Chris Fisher and Penny Nom lui répond.
Cubic yards in a pool 2004-05-30
Jerry pose la question :
HAVE A AREA WHERE I HAD A 18 FOOT ROUND POOL.
THE DEEPEST PART IT WAS IN THE GROUND WAS AROUND 7 INCHES TAPERING DOWN TO AROUND 4 TO FIVE INCHES AND A LITTLE OF THE ONE SIDE ALMOST AT GROUND LEVEL...HOW MANY YARDS OF DIRT WOULD I NEED TO FILL IT IN???? IS THERE A FORMULA FOR THAT.......COULD YOU FIGURE THAT FOR ME?

Penny Mon lui répond.
The Parliament of the land of Achronia 2004-05-29
Christine pose la question :
The Parliament of the land of Achronia consists of two houses. The parliament was elected in 2003 for a period of six years beginning on Thursday, the 1st of January 2004, when the two houses had their first sessions. According to the rules, the meetings of the first house must occur every twelve days for the duration of the term, and the meetings of the second house must occur every eighteen days. For example, the second meetings of the first and the second houses were held on the 13th and 19th of January respectively. A new law can be passed on any day when both houses meet, except on a Thursday. On how many days can the parliament members pass new laws during this six year term?
Penny Nom lui répond.
112! 2004-05-28
Beatriz pose la question :
1) A bus driver collects identical sets of 5 coins from each passenger. If the totoal colledted was $21.83, how many pennies did the driver get??

2) How many terminal zero in the base 10 expression of 112! (factional) N! means N(N-1)(N-2) .....(2) (1).

Penny Nom lui répond.
Different infinities 2004-05-27
Plober pose la question :
How can I explain to a friend (in a bar, using as a pen and a paper napkin) that the integer's infinity is 'smaller' than the irrationals's one? The demo I tried was that you couldn't match the integers with the real numbers between 0 and 1 (that 0.xxxxx replacing the Nth number from a different one... that demo), but she used my argument >:| saying that you can add one to the integer's infinite, and the number I was creating was only one more...

I can't think of any other way, and I KNOW the real's cardinality is greater than the integer's one

Claude Tardif and Penny Nom lui répond.
English 2004-05-27
Chang pose la question :
well my question is i was told by most of the teachers that ''think in english'' is the best way to learn english but how can i do like that do i need to know about the stucture first or do i need to learn the western culture ?

here is a sentence i have translate directly from my mother language.'' i was given an admiration of sincerity from this client on the follow up action i have done in the complaint.

Claude Tardif lui répond.
The horizontal fraction bar 2004-05-27
Kashia pose la question :
What is the name of the bar that separates a numerator and that denominator?
Penny Nom lui répond.
The center of a circle 2004-05-26
Wan pose la question :
I am trying to find the radius of an arc. The only things i know about the arc is all referenced from the line of tangency to the arc. on both sides i have a differnt horizontal perpendicular distance to the point of tangency. left side |-------*---------------| right side (*=point of tangency). Then i have 2 difference vertical perpendicular distance of the end points to the line of tangency. I know it sounds very bad in text but this is all i know about the arc. Can you help me find the radius?
Penny Nom lui répond.
The base of a triangle 2004-05-25
Ralph pose la question :
With a 30 degree angle at the top of a triangle and a height of 15 what is the base?
Penny Nom lui répond.
Programming without trig functions 2004-05-25
Derek pose la question :
I am a programmer trying to calculate the following.

What is the formula to find the cross-sectional area of a cylinder with out using any trig functions? or better yet, how can you calculate any given volume in a cylindrical tank with spherical heads with out trig functions?

I am using a PLC (programmable logic controller) to do this and trig functions are not available.

Harley Weston lui répond.
Finding bearings 2004-05-24
James pose la question :
This question is about finding bearings. A boat race starts from point A, goes North to Point B, a distance of 1000 meters. The course is triangular. The bearing from point B to point C is South 70degrees West. The distance from Point B to point C is 1500 meters. Find the course bearing from C to A.
Penny Nom lui répond.
Some trig expressions 2004-05-23
A student pose la question :
Prove:

sin A + sin B = 2sin(A+B/2)cos(A-B/2)

cos A - cos B = -2sin(A+B/2)sin(A-B/2)

cos A + cos B = 2cos(A+B/2)cos(A-B/2)

sin A - sin B = 2cos(A+B/2)sin(A+B/2)

Penny Nom lui répond.
Volume of a box 2004-05-23
A student pose la question :
The area of the top of a closed rectangular box is 252cm2, the area of the front of the box is 105cm2, and the surface of the box is 834in2 (or 5380.64cm2). What is the volume of the box?
Penny Nom lui répond.
How far apart are they? 2004-05-23
A student pose la question :
2 cars start at same loc. drive opposite direction for 6 miles then they each turn left and travel for 8 miles how far apart are they?
Penny Nom lui répond.
33 3/4 doubled 2004-05-22
A tailor pose la question :
need to know how to add 33 3/4 doubled. How do I come up with the solution? I need to know for measuring garments. Usually I measure on the half meaning on the front of the garment and then double it with the measuring tape but I always get stuck when I need to measure 3/4 such as 66 3/4 doubled and etc. Can you help me figure this out easily.
Penny Nom lui répond.
The perimeter of a triangle 2004-05-21
A student pose la question :
In a triangle i have the length of a line and it's opposite angle.how can i calculate perimeter?(the angles are not right)
Penny Nom lui répond.
Frieze patterns 2004-05-19
Christina pose la question :
How can I prove that there are only seven unique geometric frieze patterns?
Penny Nom lui répond.
Word problems 2004-05-19
A student pose la question :
why can't 2nd graders have a easy time doing word problems and drawing pictures with it
Diane Hanson lui répond.
The dimsenions of a room 2004-05-18
Estella pose la question :
I have a room that is rectangular the area is 159.5 feet, the perimeter is 51 feet what would the dimensions of the room.
Penny Nom lui répond.
Angles of elevation and depression 2004-05-18
Anjum pose la question :
what is the difference between an angle of elevation and angle of depression?
Penny Nom lui répond.
The combinatiion for a keybox 2004-05-17
Darrin pose la question :
I have a puzzle question based on reality. I have a real-estate type keybox (Supra) that has 10 digits, 0-9. I am trying to figure out a methodical way to test all number combinations to it to open it. (totally legal- it was taken from the trash at a jobsite since they couldn't open it!) The combination could be any or all of the digits, but any digit is only used once. This is not like a simplex lock problem where a combination of keypresses would be different- i.e. 1,2,3 is the same as 1+2,3. Any ideas?
Penny Nom lui répond.
Diagonals in a regular dodecahedron 2004-05-15
Joshua pose la question :
A dodecahedron has twelve faces, all of which are regular pentagons. Three edges meet at each vertex of the dodecahedron. An interior diagonal is a segment connecting two vertices such that the segment is not an edge or along a face of the dodecagedron. How many interior diagonals does a regular dodecahedron have?
Penny Nom lui répond.
Maximizing the angle to the goal mouth 2004-05-15
Yogendra pose la question :
You are running down the boundary line dribbling the ball in soccer or hockey. Investigate where in your run the angle the goal mouth makes with your position is at a maximum.
Penny Nom lui répond.
Mrs. Smith's class 2004-05-12
Amanda pose la question :
Mrs. Smith's class has 35 student. Today there are 2/3 of them absent. How many are absent? present?
Penny Nom lui répond.
Subtracting fractions 2004-05-11
Filipe pose la question :

Question:
_5_ - __7__
6ab 8a


Penny Nom lui répond.
Area of a lot 2004-05-11
Dana pose la question :
HELLO MY NAME IS DANA ,I AM AN AVERAGE JOE WITH A QUESTION THAT I CANNOT ANSWER MYSELF SO I CAME TO YOU, I HAVE A PIECE OF PROPERTY IN THE SHAPE OF AN ISOSCELES TRAPEZOID THAT IS 250 FEET ACROSS THE BACK, 100 FEET ACROSS THE FRONT AND BOTH SIDES ARE 600 FEET LONG. HOW MANY SQUARE FEET ARE IN THIS PROPERTY.?
Penny Nom lui répond.
A pyramid 2004-05-11
Quiana pose la question :
I am a student and I have the following questions I need to answer for homework:
How many sides, vertices, and edges does a pyramid have?

Penny Nom lui répond.
Three dice 2004-05-10
A student pose la question :
If one has 3, 6 sided dice what is the probability of the numbers that are rolled to total 4 through 10 inclusively?

Subsequent to this, what is the probability to do this consecutively...say 3 times?

Peny Nom lui répond.
Pi 2004-05-10
Kim pose la question :
I'm a 7th grader at Lakeside Middle School. And I was wondering if you can answer a question for me for my math project. I'm doing a project on pi, and my teacher said to ask an expert like you to ask about how you would use the subject, pi, in real life usage. How would you use pi in real life usage?
Penny Nom lui répond.
Why the word combinations? 2004-05-05
Megan pose la question :
Why are locker combinations called locker combinations not locker permutations. The order of the numbers matter so why aren't they called locker permutations.
Claude Tardif and Penny Nom lui répond.
Chi-Squared 2004-05-05
Gillian pose la question :
OF75 PEOPLE, 43 ARE EXPOSED TO A VIRUS AND BECOME ILL. 11 PEOPLE ARE EXPOSED AND DO NOT BECOME ILL. 3 PEOPLE ARE NOT EXPOSED AND BECOME ILL. 18 PEOPLE ARE NOT EXPOSED AND DO NOT BECOME ILL. THE ATTACK RATE IS 80% FOR THOSE EXPOSED AND 14% FOR THOSE NOT EXPOSED. THE RELATIVE RISK IS 5.7. CAN YOU EXPLAIN TO ME HOW TO CALCULATE A CHI SQUARE TEST FROM THIS.
Penny Nom lui répond.
3x squared - 27 / x + 3 2004-05-04
Stef pose la question :
3x squared - 27 / x + 3
Penny Nom lui répond.
A 3 digit number divisible by 7 2004-05-03
A student pose la question :
We need to arrange 1,3 and 6 to form a 3 digit number that is divisible by 7.
Penny Nom lui répond.
Solving inequalities 2004-05-03
Joe pose la question :
Let x be a real number find and graph the solution to the following sentances:

2x-10+9 4X+2<15 5X+3>(x-1)

Peny Nom lui répond.
A clock chimes 7 times in 7seconds 2004-05-02
Anna pose la question :
A clock chimes 7 times in 7seconds. how long does it take the clock to chime 10 times?
Penny Nom lui répond.
The equation of a line 2004-04-30
Amy pose la question :
Write the equation of the line that contains the point (-4,6) and is perpendicular to the line y=5x+100.
Penny Nom lui répond.
Setting up an equation 2004-04-30
Matt pose la question :
I am trying to determine the dimensions of a 22 megapixel digital camera chip that has a 3:2 ratio. We know then, that: 3x = 2y (or 1.5x = y)

and that

xy = 22

Beyond this, I don't know how to hook those 2 seemingly unrelated facts together.

Penny Nom lui répond.
The sum of 4,0,-4..., -156 2004-04-28
Christina pose la question :
find the requested sum of the arithmetic sequence

4,0,-4..., -156

Penny Nom lui répond.
Yards in a concrete driveway 2004-04-27
Bobbi pose la question :
I am wondering how many yards of cement I need for a 49 by 45 area, 5 inches thick. I am a stay at home mom who is not very good at math and I want to pave my drive way. Also what would the yardage be for a 6 inch thick drive way with the same area.
Penny Nom lui répond.
Factoring 2004-04-27
Bipin pose la question :
FACTORISE:

a to the power of 6 + b to the power of 6

Penny Nom lui répond.
An oil-drilling platform 2004-04-27
Alie pose la question :
An oil-drilling platform is located in the Gulf of Mexico 3.25 miles from the nearest point on shore. From a point B on the shore due east of A the bearing of the platform is S51.2W. How far is it from B to the platform?
Penny Nom lui répond.
The height of a triangle 2004-04-27
Danielle pose la question :
what is the definition of height of a triangle?
Penny Nom lui répond.
Related rates and baseball 2004-04-26
Bethany pose la question :
A baseball diamond is the shape of a square with sides 90 feet long. A player running from second to third base at a speed of 28 feet/ second is 30 feet from second base. At what rate is the player's distance from home plate changing?
Penny Nom lui répond.
The problem of Apollonius 2004-04-25
Mitja pose la question :
There are given 2 circles lying one out of another and one point out of both circles. How to construct a circle passing through a given point and internally tangent to one and externally tangent to the other cirlce?
Chris Fisher lui répond.
A Fibonacci triangle 2004-04-25
Marcelle pose la question :
Is it possible to construct a triangle with sides that are three consecutive Fibonacci numbers?
Walter Whiteley lui répond.
Water in a pipe 2004-04-25
Marlean pose la question :
How much water would be in a 480 foot one inch inside diameter pipe?? In imperial gallons please. thanking you in advance for your help in this matter.
Penny Nom lui répond.
Place Value 2004-04-25
Santosh pose la question :
Q. Write the Place value of the digits in the following numerals.

1. 5 in 54
2. 3 in 63

Penny Nom lui répond.
Marching legion 2004-04-24
Art pose la question :
A column of soldiers is 100 meters long. Their sargeant at the rear of the column gives the order to march. The sargeant marches alongside the column to its head and then back to the rear, at which point he gives the order to halt. In all, the column of soldiers has marched 100 meters. How far has the sargeant marched? I say 187.5 meters, but those who teach or who have taught mathematics tell me no. Some say much more and some different. What do you say?
Penny Nom lui répond.
Three parabolas 2004-04-24
A tutor pose la question :

I am a maths tutor. One of my year 12 students has given me this assignment. Many parts are ambiguous. I am trying to determine the equation of the line segment AB. Given that A has an incline of 10 degrees below the horizontal, I am assuming that this parabola (although you can only see part of it) has been rotated 10 degree clockwise. Am I right in assuming this? If so, how do I derive the equation of the parabola as it will then not fit the general form y = ax squared +bx +c of a parabola.

Also, how is one expected to find the x coordinate of D without the equation of this parabola. To find the equation you need the x-coordinate and therefore be able to find another point on the parabola in order to derive the equation using simultaneous equations.


Penny Nom lui répond.
Arrays 2004-04-23
Jan pose la question :
4x7 = 28
How many arrays can this have? How do you
determine the arrays???

Penny Nom lui répond.
square root 125 x 16 2004-04-23
Mike pose la question :
how do you simplify a square root of "- square root 125 x16" when x is a variable... i don't really get how to do this....
Penny Nom lui répond.
The "22" puzzle and the "1089" puzzle 2004-04-22
Marcelle pose la question :

1. Choose 3 digits from 1-9
2. Make all the 2 digit numbers you can from these (6)
3. Add the 3 original digits and divide them into the sum from step 2.
The answer is always '22'. I just can't understand why. Can you please help.

Another one related to this is it:
1. Choose a three digit number ensuring the first and third digit are differnt by at least two.
2. Make the reverse three digit number and subtract the smaller one from the larger of these.
3. Take this answer and reverse it and add these two 3 digit numbers .

eg:
643 - 346 = 297
297 + 792 = 1089

it doesn't matter what numbers are used, the results are alwasy the same. eg 22 or 1089


Paul Betts lui répond.
Why is ounces abbreviated oz? 2004-04-22
Someone curious pose la question :
Why is ounces abbreviated oz?
Chris Fisher lui répond.
What's it called? 2004-04-22
Gerry pose la question :

I'm a father and a grandfather and have come up with a game for my offspring to play while we're on the road. When we see a license plate, the object is to be the first one to add all the numbers on it, and come up with THE one digit number that sums them up.

For example: ABC-787 = 7+8+7 = 22 = 2+2 = 4

Another example is 2932 = 2+9+3+2 = 16 = 1+6 = 7

Up 'til now, I've called it just plain "Numerology", but I'm sure that there's a math term for what we're doing, and I'd sure appreciate it if you could tell me what it is!


Chris Fisher and Penny Nom lui répond.
Surface area of a cylinder 2004-04-17
Kathryn pose la question :
How do you find the radius of a cylinder when you are given only the surface area and the height of the cylinder?
Penny Nom lui répond.
The line through (4,2) and (4,-8) 2004-04-17
Kim pose la question :
Write an equation for the line.
Given points (4, -8) and (4,2) are on the line.
I believe m=undefined.

How do I solve for b when m is undefined, and then plug in the values for m, b, and y?

Penny Nom lui répond.
Some factoring problems 2004-04-15
KJ pose la question :

Factor these:
x3+125 -----> (x+5)3
8x3-27 -----> (?)
x2+36 -----> (x+6)2
x4-5x2+4 --> (?)


Penny Nom lui répond.
A probability density function 2004-04-14
A student pose la question :
The label on a bottle of liquid detergent shows contents to be 12 ounces per bottle. The production operation fills the bottle uniformly according to the following probability density function:

f(x) = 8 for 11.975 <= x <= 12.10
and
f(x) = 0 elsewhere

a. What is the probability that a bottle will be filled with 12.02 or more ounces? b. What is the probability that a bottle will be filled between 12 and 12.05 ounces? c. Quality control accepts production that is within .002 ounces of number of ounces shown on the container label. What is the probability that a bottle of this liquid detergent will fail to meet the quality control standard?

Penny Nom lui répond.
A geometric sequence 2004-04-13
Michael pose la question :
In a geometric series, the sum of the 2nd and 3rd terms is 60, and the sum of the 3rd and 4th terms is 240. Find the sum of the first 7 terms.
Penny Nom lui répond.
Circles in a hexagon 2004-04-11
Crystal pose la question :
step by step can you show me how to calculate the area of the region inside the hexagon but outside the seven circles. given the radius of each circle is one inch
Penny Nom lui répond.
Percent difference 2004-04-10
A parent pose la question :
For a school science project, my son Alex is taking measurements of plant growth at regular intervals. As part of the data, he must provide the maximum percent difference observed in the categories his team has identified.

So, for example he has six plants with four measurements each. (He has more, but I'll keep it simple) For the first plant he measured 2mm, 2.4mm, 2.9mm, and 3.2mm. For the 2nd, 3rd, and 4th plants, he has similar numbers. Is there a way to calculate the maximum percent difference between any two plants in his measurements during the project? Doing it for each combination would be tedious.

Penny Nom lui répond.
Snow in the driveway 2004-04-09
Patricia pose la question :
Following a severe snowstorm, Ken and Bettina Reeves must clear their driveway and sidewalk. Ken can clear the snow by himself in 4 hours, and Bettina can clear the snow by herself in 6 hours. After Bettina has been working for 3 hours, Ken is able to join her. How much longer will it take them working together to remove the rest of the snow?
Penny Nom lui répond.
What is the nth term 2004-04-07
Jason pose la question :
1 4 10 20 35 56 84
what is the nth term

Claude Tardif lui répond.
Rational expressions 2004-04-06
Shivani pose la question :
I am in 11th grade Honors Algebra II. We are currently learning about adding and subtracting rational expressions. I looked at the other questions that were similar to that of mine, but they weren't quite answering my question. I have been working on many problems to practice and see if I can come up with the correct answer, but I can't, I got like 2 out of every 7 right on my school homework. I get the easy ones, where when you have to find the LCD, it's just the other denominator. But, on others you have to really think about it. Those are hard. Here are some of the problems that I cannot get at all: (x2 - 3x + 1)/(x2 - 4) - (x2 + 2x +4)/(2 - x) - (x - 4) /(x - 2)

The correct answer is: (x3 + 4x2 + 7x + 17)/(x2 - 4)

Penny Nom lui répond.
The sum of angles in a triangle 2004-04-06
A student pose la question :
How can u prove sum of angles in a triangle equal to 180 degrees?
Penny Nom lui répond.
Differences in percentages 2004-04-06
Jose pose la question :

Question:
You have two groups:

Group A has 10 people and 2 are Chinese
Group B has 12 people and 3 are Chinese

In terms of percentages what is the difference in Chinese between the two groups? In other words which group has the biggest percentage of Chinese and why?


Penny Nom lui répond.
Trisecting an arbitrary angle 2004-04-06
Joe pose la question :
Where can I submit my effort on trisecting an arbitrary angle with only a straightedge and a compass? I can do it but I do not have the smarts to prove it.S
Chris Fisher lui répond.
Ratios 2004-04-05
Tim pose la question :
The ratio of W to H was 7 to 9. The ratio of H to I was 9 to 5. If the sum of the W and H exceeded twice the number of I by 12, how many were W, how were H and how many were I?
Penny Nom lui répond.
x^2/3 - 7 x^1/3 + 12 = 0 2004-04-05
Jackie pose la question :
I am having trouble solving this question for x:

1.) x^2/3 - 7 x^1/3 + 12 = 0

Penny Nom lui répond.
(3x50)+20/5=? 2004-04-03
A student pose la question :
what is the answer to:

(3x50)+20/5=?

Penny Nom lui répond.
A changing rectangle 2004-04-03
A student pose la question :
The width x of a rectangle is decreasing at 3 cm/s, and its length y is increasing at 5 cm/s. At what rate is its area A changing when x=10 and y=15?
Penny Nom lui répond.
Ratio and proportion 2004-04-02
Kenneth pose la question :
The terms of a ratio in a proportion are often expressed as a is to b as c is to d.

Example: 2/4 = 6/12 this proportion represents that 2 is to 4 as 6 is to 12.

What does the "a is to b as c is to d" really represent or indicate in ratios?

Claude Tardif lui répond.
Some calculus problems 2004-04-01
Weisu pose la question :

I have questions about three word problems and one
regular problem, all dealing with derivatives.

  1. Find all points on xy=exy where the tangent line
    is horizontal.
  2. The width x of a rectangle is decreasing at 3 cm/s,
    and its length y is increasing at 5 cm/s. At what rate
    is its area A changing when x=10 and y=15?
  3. A car and a truck leave the same intersection, the
    truck heading north at 60 mph and the car heading west
    at 55 mph. At what rate is the distance between the
    car and the truck changing when the car and the truck
    are 30 miles and 40 miles from the intersection,
    respectively?
  4. The production P of a company satisfies the
    equation P=x2 + 0.1xy + y2, where x and y are
    the inputs. At a certain period x=10 units and y=8
    units. Estimate the change in y that should be made to
    set up a decrease of 0.5 in the input x so that the
    production remains the same.

If you could just give me some hints on these
questions, I'd really appreciate it. Thanks!


Penny Nom lui répond.
The intersection of two graphs 2004-03-31
Benjanim pose la question :
How do I find the points of intersection of the two functions:

1) y = 2 - (e^-x)
2) y = 1 + (x^2)

I know that I have to set them equal to each other, but I can't solve for x. Please help :-)

Penny Nom lui répond.
Algebraic simplification 2004-03-31
Chris pose la question :
Simplifying Exponents

Question

b^5d^2/b^3d^8

Penny Nom lui répond.
The degree sequence of a graph 2004-03-31
Ali pose la question :
How can i find out {6,6,5,5,5,3,2}is not the sequence of the points of a simple graph,without drawing it?
Penny Nom lui répond.
Replacement times for TV sets? 2004-03-31
Barb pose la question :
Replacement times for TV sets are normally distributed with a mean of 8.2 years and a standard deviation of 1.1 years. Estimate the probability that for 250 randomly selected TV sets, at least 15 of them have replacement times greater than 10.0 years.e
Andrei Volodin and Penny Nom lui répond.
A derivative 2004-03-31
A student pose la question :
What is the nth derivative of f(x) =(2x)/(1-(x2))?
Harley Weston lui répond.
The height of a building 2004-03-31
Nat pose la question :
Two buildings are 26.3m apart. From the top of the shorter building the angle of elevation to the top of the taller building is 35.9 degrees and the angle of depression to the base of the taller building is 54.7 degrees. What is the height of the taller building?
Penny Nom lui répond.
425 cc's of a saline solution 2004-03-30
Julie pose la question :
425 cc's of a saline solution is equal to how much in lbs-weight??
Harley Weston lui répond.
n! > n^2 2004-03-30
Jose pose la question :
How can you prove by mathematical induction that:

n! > n2.

Penny Nom lui répond.
A stained glass window 2004-03-29
Kay pose la question :
I'm doing a stain glass project and it's on a 4 foot across octagonal window...and I'm trying to set up the pattern and I don't know how long the sides are!
Penny Nom lui répond.
Numbers around a circle 2004-03-28
Rebecca pose la question :
my maths question is use the numbers 1,2,3,4,5,6 and 7 place each number in a circle so each line adds up to 12. There are seven circles, six on the outside and one in the middle. Each number lines up with the middle number and the outside numbers line up with the one directly across from it as if a line was going through the middle number circle.
Penny Nom lui répond.
Percentage difference 2004-03-28
Someone pose la question :
what is the percentage difference between 157 to 251
Penny Nom lui répond.
Maximizing the area 2004-03-27
Petey pose la question :
Please could you tell me why for my coursework (where I have to find the largest area that a fence 1000m long can cover) why I should only test equilateral and isoceles triangles? We were told NOT to do right angled triangles but I was wondering why not?
Penny Nom lui répond.
The volume of a sphere 2004-03-26
Mike pose la question :
I was in class today and I learned how to calculate the volume of a sphere. I understood it easily but can't find the logic behind it. So here are my questions, in the formula why is the radius cubic and not squared? And what does 4/3 have to do with it?
Penny Nom lui répond.
z^2 = 3 - 4i 2004-03-26
John pose la question :
Solve: Z^2 = 3 - 4i
Harley Weston lui répond.
Large exponents 2004-03-26
John pose la question :
I have encountered problem with the lack of memory every calculator seems to have. No calculator, on or off the computer, I've found has the amount of memory or writing space to calculate the sums I want to solve. The sums are in great importance for my continued progress. The sums are following:

16777216^1310270, 16777215^995328, 16777215^786432 and 16777215^480000

Claude Tardif lui répond.
Sections, area and acres 2004-03-23
Tony pose la question :
An acre , it can be any size right . so when they refer to a section of a township which is 640 acres, also 1 square mile does this mean that 1 sections length if sqaure and there is 5,280 ft in 1 mile does it meanthat if you took 1 side of the square of of 4 sides the lenth would be 5,280 feet long and by multiplying 5,280 x 5,280 it would give you the square mile in square feet. i guess what I 'm asking is what is the perimeter of 1 acre if it was shape like a square. sorry to make this confusing but if you can help I would appreciate it.
Penny Nom lui répond.
Four marbles on a box 2004-03-22
Karyn pose la question :
Suppose 2 solid color marbles and 2 striped marbles are placed in a box. All are the same size. If one marble is randomly drawn from the box and replaced, then a second marble is randomly drawn, what is the probability that the marble drawn both times will be striped?

I know there is a simple formula for working this out but I can't remember how.

Penny Nom lui répond.
What's the next term? 2004-03-22
Garrett pose la question :

A friend hit me with these questions and won't tell me the answer nor how... please help? I've racked my brain and did all sorts of formulas, but I can't get it to work out... please...

What's the next number in this series... 5, 12, 17, 29, 46, ?

And this series... 12, 19, 28, 39, 52, 67, ?

and these... ocoa, boco, oboc, dobo, odob, ?


Claude Tardif lui répond.
BEDMAS 2004-03-20
Brad pose la question :
I am in grade 7. My teacher tells me brackets always first, well i know that but, 5 (-4) x 2

Does the (-4) count as a bracket or is it just telling you not to minus 4 from 5 but to multiply 5 x -4 ? Am i correct?

Penny Nom lui répond.
A partial derivative 2004-03-19
Penny Nom pose la question :
Is it possible to differentiate the following equation, if so could you please explain.

S=SQRT(T-(5/X^2))

I would like the derivative of S with respect to X.

Harley Weston lui répond.
A fraction of a fraction as a percent 2004-03-18
Mary pose la question :

I would like to know if you could help me with this problem? Could you take me though the steps
to this math problems.

 3 =(?)% x 3
---       ---
16         4
	  

the question states: Finding what is the percentage of a fractional number and another fractional number.


Penny Nom lui répond.
A water lily 2004-03-17
Inba pose la question :
A water lily with a rigid stem extends one foot above the surface of the water. When pulled over, it disappears beneath the water at a distance 3 feet from where the stem originally entered the water. How deep is the pond?
Penny Nom lui répond.
Factoring x^2 + 5x + 4 2004-03-14
Keenan pose la question :
how do I factor x^+5X+4?
Penny Nom lui répond.
Johann Muller 2004-03-14
A student pose la question :
What major contributions to spherical trigonometry did Johann Muller make?
Penny Nom lui répond.
Baseball games 2004-03-14
Fabian pose la question :
Let's say I have 12 different Baseball games. There is one of only 2 possible outcomes for each of the 12 games. How would I fugure out how many combinations there are for the 12 games and for 11,10, and so fourth.
Penny Nom lui répond.
A new baby 2004-03-14
Jessica pose la question :
I just had a baby 3weeks ago, he is in the hospital and he can come home when he is 1800 grams, well i was wondering how many pounds that is?
Penny Nom lui répond.
Some ratio problems 2004-03-13
Hossen pose la question :

1) After James spent 2/5 of his pocket money on magazines, and 1/4 of his pocket money at a football match, he had £1.75 left. How much pcket money did he have in the beginning?

2) A joint of Lamb costs £5.95 per/kg. The price per kilogram is reduced. A joint weighing 1.2kg is reduced by 50p.

A) What is the reduced price per kilogram?

c

Penny Nom lui répond.
Billions in Australia 2004-03-12
An Australian pose la question :
how many million in one billion ?
Penny Nom lui répond.
Area and perimeter 2004-03-12
Sandy pose la question :
The rectange has an area of M square units and a perimeter of 2M units. What is the value of x?

The length of the rectange is 3, while the width of the rectange is x-1.

Penny Nom lui répond.
Sum of the angles in a pentagon 2004-03-11
Ashish pose la question :
What is the sum of all the measures of the angles of a Pentagon
Penny Nom lui répond.
Distance, time and rate 2004-03-09
Peter pose la question :
A car travels from one city to another at the speed of 32mph, if it had gone 4mph faster it could have made the trip in one half hour less. How far apart are the cities?
Penny Nom lui répond.
The area of a lot 2004-03-09
Dave pose la question :

If our lot is 192.71 x 138.79 x 158.74 x 103.08

Question is what percentage of an acre is our lot?


Penny Nom lui répond.
The factor theorem 2004-03-08
LisaMarie pose la question :

Hi, I have a career link question from gr.12 advanced functions and intro. calculus. The equations is:

R(t) = 5(t4 - 4t3 + 19/4 t2 - 3/2 t)

The question is to apply the factor theorem and quadratic formula to determine the times it crosses the t axis. The only method i know of for using the factor theorem is when the last number does not have a variable beside it so i'm not sure how you would even use the factor theorem for this? We haven't dealt with any that have 0 as the last number with no variable so i'm a little confused! please help!

Thank you

Penny Nom lui répond.

A metric prefix table 2004-03-07
April pose la question :
Can you tell me what the scale is for nano, micro, mega, kilo, etc.... I know that mega is 10 to the sixth power but I can't remember the other ones.
Penny Nom lui répond.
Equivalent sets 2004-03-06
A student pose la question :
If A=(1,2,3,4,...) and B=(5,10,15,20,...), is A equivalent to B. Why or Why not ?
Penny Nom lui répond.
The radius of a circle 2004-03-06
A student pose la question :
what is the radius of a circle with the circumference of 12 inches?
Penny Nom lui répond.
The units digit of 4^478 2004-03-06
Elizabeth pose la question :
What is the units digit of 4478?
Penny Nom lui répond.
A fifteen sided polygon 2004-03-05
Joann pose la question :
WHAT IS THE NAME OF A FIFTEEN SIDED SHAPE?
Penny Nom lui répond.
A geometry problem 2004-03-04
Jennifer pose la question :
I need help with this problem: Square ABCD has side length 2. A semicircle with diameter AB is constructed inside the square, and the tangent to the semicircle from C intersects side AD at E. What is the exact length of CE?o
Chris Fisher lui répond.
Cosine of 35 degrees 2004-03-03
Jason pose la question :
How do you find the exact solution to cosine 35 degrees.
Chris Fisher lui répond.
Proof by induction 2004-03-02
Chris pose la question :
I need some help of how to solve the problem

"use the principle of mathematical induction to prove that the following are true for all positive integers"

cos(n x pi + X) = (-1)^n cosX

any help would be appreciated

Penny Nom lui répond.
Volume of a fuel tank 2004-03-01
Mike pose la question :
I have a fuel ank for my big truck that has a radius of 24inches and a length of 65 inches. I am trying to compute the volume of fuel in the tank. I tried pie x the radius squared times the length but no usable results. Can you help me please?
Penny Nom lui répond.
Billions and more! and even more! 2004-03-01
Steph pose la question :
What comes after undecillion?
Penny Nom lui répond.
Even-numbered roots 2004-03-01
A student pose la question :
I understand that the square root is defined to be positive only. Does the same rule apply to other even-numbered roots, such as the 4th root, or the 6th root, etc.?
Harley Weston lui répond.
Logs 2004-02-29
Sandy pose la question :
find X
3/2logb4-1/2logb8+logb2=logbx

my book uses prop 7 to rewrite as logb4raised3/2-logb8raised2/3+logb2=logbx; then writes logb8-logb4+logb2=logbx how did it get here?

Claude Tardif lui répond.
A dress-maker's pattern 2004-02-27
A dress-maker pose la question :
Does a dress-maker's pattern for a dress, such as a skirt made up of several pieces of isosceles trapezoid, qualify as a net? How about patterns for other types of clothing or accessories e.g. jackets, handbags?Î
Diane Hanson lui répond.
Napoleon's theorem 2004-02-27
David pose la question :
How do i prove this : For any triangle, if you make 3 equillateral triangles using the sides of the the original triangle, the central points of the 3 tringles another triangle that is equillateral.z
Chris Fisher and Penny Nom lui répond.
GST and PST 2004-02-26
Mallory pose la question :
I was absent on the day that my teacher taught the class how to find the GST and PST of items. I sort of understand that GST is 7% and PST is 7.5%, but our teacher said that we shouldn't combine the two to find the total amount... I'm really confused, so can you please help me?&
Claude Tardif lui répond.
Three jugs 2004-02-26
Shelly pose la question :
You have three jugs: A 6 Liter, 4 Liter and a 3 Liter. Your goal is to get exactly 5 Liters of liquid in the 6 Liter jug. Your supply of liquid is unlimited and there are NO markings on the containers. You cannot do halves.
Claude Tardif lui répond.
The point where all the medians meet 2004-02-25
A student pose la question :
What's the name of the point where all the medians meet?
Penny Nom lui répond.
Rearranging an expression 2004-02-24
Corey pose la question :

use the following formula to answer the question F=9c divided by 5 plus 32

rearange the formula to solve for c
how many degrees fahrenheit would it be it it was:
0 degrees celcius
-10 degrees celcius
-46 degrees celcius


Penny Nom lui répond.
An elliptic cone 2004-02-24
Ben pose la question :

I am building a model for my architecture class. I need to build a elliptic cone out of chipboard and i have no idea how to do this.

The cone needs to be 20in tall and the ellipse has a max radius of 10in and a min radius of 8in.

So my question is how do i lay this out on a piece of paper so that i can form the cone after i cut it out.


Penny Nom lui répond.
Profit, markup and discount 2004-02-22
Kick pose la question :
Using the calculation on your website, if I sell something for $885 and my cost is $296, I make $589 profit. How do I calculate the profit percent I made on that transaction?

Profit as a percentage of what it cost me?
Profit as a percentage of what I sold it for?

Penny Nom lui répond.
A problem with logs 2004-02-22
Caitlyn pose la question :
problem: ln x + ln (x-2) = 1

I can solve this on the calculator, but the book wants 1+ [(sqroot)1+e]. How can I get the e?

Penny Nom lui répond.
Selecting balls from a golf bag 2004-02-21
A student pose la question :
There are 5 white and 5 yellow balls in a golf bag. Two are selected randomly, and simultaneously. What is the probability that the first one or the second one will be white?
Penny Nom lui répond.
The dimensions of a rectangle 2004-02-21
Jane pose la question :
A rectangular label has an area of 176cm2 and a perimeter of 54cm. Find the dimensions of the label.
Penny Nom lui répond.
Gallons in a cylinder 2004-02-20
Jim pose la question :
Please advise how to use the formula I saw for determining the number of gallons in a cylinder? This is how it was written V = pi r2 h . does this mean pie, or 3.14 X radius squared, X the height? If so please use a standard 55 gal barrel (1' R & 3' H) for example?
Penny Nom lui répond.
Arrays 2004-02-19
A parent pose la question :
please demonstrate mathematical arrays fro a 3rd grader
Penny Nom lui répond.
A worm crawling home 2004-02-18
Cindy pose la question :
A worm is crawling to his home which is one meter away. The longer he crawls the weaker he gets and the less he can crawl the next day. If he crawls within 1/3000 of a meter of his home, he will find food. He must eat within twelve days. The first day he crawls 1/2 meter. The second day he crawls 1/4 meter. The third day he crawls 1/8 of meter. This pattern continues for twelve days. Make a Chart that shows the distance he has covered at the end of each day and the total he has covered at the end of each day. Does he make it to the Food in time?
Penny Nom lui répond.
Nonconvex shapes 2004-02-18
Merrill pose la question :
Draw 4, 6 and 8 sided shapes so that ONE straight line can be drawn through each side
Chris Fisher and Penny Nom lui répond.
Acres and square miles 2004-02-17
Richard pose la question :

How many acres are in .17 square miles? and How many acres are in .6 square miles?

The two areas I am requesting information about are Vatican City and San Marino, the two smallest countries in the world. If I can transfer the sq. miles into acres , I can relate the size of these countries to our school grounds and the students will better understand their sizes.


Penny Nom lui répond.
Grams and Milliliters 2004-02-17
Chantal pose la question :
We have to do a "thing", and I need to convert grams into mililitres (g into mL). how can I do this?
Penny Nom lui répond.
Areas, perimeters and derivatives 2004-02-15
Geoff pose la question :
A recent lecture in my calculus class led me to realize that the derivative of the area of a circle, with respect to the radius is equal to the circumfrence. This also holds true for the relationship between the volume of a sphere and the surface area of that sphere:
why do these hold true? why is it only for circular objects?

Harley Weston lui répond.
An arc on a train track 2004-02-15
A student pose la question :
I'm trying to build a route in a train simulator program. I have a curve to the right (an arc, in other words) with a length of 25 meters and the radius is 1,500 meters. Let's say point P is the beginning of the curve (arc) and point Q is the end point of the arc. Then picture a tangent to point P. I need to find the length of a line perpendicular to that tangent that runs to point Q (the end of the curve/arc).
Penny Nom lui répond.
The derivative of x to the x 2004-02-14
Cher pose la question :
what about the derivative of x to the power x?
Penny Nom lui répond.
The substitution method 2004-02-14
Keisha pose la question :
I need to solve this problem by using the substitution method.
3x+y=1
x=2y+5
Please help me understand the method to solve.

Penny Nom lui répond.
Probabilities and olivies 2004-02-14
Annetta pose la question :
A bowl contains five green olives and eight black ones. Wilma sticks a fork into a bowl and brings out two olives. What is the probability that she gets one green and one black olive?
Harley Weston lui répond.
Red riding hood 2004-02-14
Frank pose la question :
Red riding hood had a number of jars to take to grandma's house. As she traveled she gave away 1/3 of them to an old lady. Then later As she walked through the forest a wolf stole 1/2 of her remaining jars. When she arrived at grandma's house she gave her 2/3 of the remaining jars. She kept 6 jars for herself. How many jars did she start out with.
Diane Hanson lui répond.
A pyramid-shaped tank 2004-02-13
Annette pose la question :
The base of a pyramid-shaped tank is a square with sides of length 9 feet, and the vertex of the pyramid is 12 feet above the base. The tank is filled to a depth of 4 feet, and water is flowing into the tank at a rate of 3 cubic feet per second. Find the rate of change of the depth of water in the tank. (Hint: the volume of a pyramid is V = 1/3 B h , where B is the base area and h is the height of the pyramid.)
Harley Weston lui répond.
Fractions 2004-02-13
A parent pose la question :
12/36=?/18=4/?=?/9
Penny Nom lui répond.
Common fractions to decimals 2004-02-12
A parent pose la question :
I'm trying to help my son work with turning fractions into decimals and this seems foreigh to me after 20 years of not being in school. Can you give me a few illustrations and/or examples of how to do that??
Penny Nom lui répond.
Profit 2004-02-12
Mohamed pose la question :
if i bought some thing with 100$ and the saller told me that his profit was 30% how can i know the actual price of the good
Penny Nom lui répond.
Zero 2004-02-12
Syazwan pose la question :
can you tell me who and when the number zero was discoveredd
Penny Nom lui répond.
Three numbers are added in pairs 2004-02-12
Jane pose la question :
When three numbers are added in pairs, the sums of the pairs are 22, 39, and 45. What are the three numbers?
Penny Nom lui répond.
Driving from Sarnia 2004-02-11
Jane pose la question :
"Crystal drove from Sarnia at 80km/hr. Emily left Sarnia one hour later and drove along the same road at 100km/hr. How far from Sarnia did Emily overtake Crystal?"
Claude Tardif lui répond.
Digits in the decimal expansion 2004-02-11
Leslie pose la question :
In the decimal expansion of 1/17 what digit is in the 1997th place?
Penny Nom lui répond.
Sums and differences 2004-02-10
David pose la question :
The sum of two whole numbers is 63. The difference between the numbers is 10. Find all the possible pairs.
Claude Tardif and Penny Nom lui répond.
Three times a year 2004-02-09
Graham pose la question :
What is the term for a report that is submitted three time a year or at the very least a prefix term for one third
Harley Weston lui répond.
Will be shinning in 36 hours? 2004-02-08
Kim pose la question :
It is noon, you lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on you radio you hear that weathercaster predicts that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shinning in 36 hours? Justify your answer.
Penny Nom lui répond.
Graphing lines 2004-02-08
A student pose la question :
how do you solve y=1\3x+3 and y=1\3x-3 by graphing?
Penny Nom lui répond.
A/30 + B/105 = (7A + 2B)/x 2004-02-05
Jim pose la question :
If A/30 + B/105 = (7A + 2B)/x and A, B, and x are integers greater than 1, what must x equal?
Penny Nom lui répond.
A quadratic word problem 2004-02-04
Carl pose la question :
A walkway of uniform has 72m2 and surrounds a swimming pool that is 8m wide and 10m long. Find the width of the walkway.
Penny Nom lui répond.
$20,000 at 25% compounded daily 2004-02-03
A student pose la question :
Hi there, I'm tying to figure out how much interest I would pay on 20,000 if it was 25% compounded daily.
Penny Nom lui répond.
Geometric sequences 2004-02-03
Alan pose la question :
hello, I am a junior in precalculus. we started working on geometric sequences today, it makes perfect sense on how it works. but why is it called that? if you could send me an answer to why geometric sequences have that name, I would be much appreciative.
Chris Fisher lui répond.
The volume of a tetrahedron 2004-02-03
Joseph pose la question :

How do I calculate the volume of a bird tetrahedron. I'm trying to find out to get extra credit. I came with this idea while making a origami tetrahedron.

Joseph

P.S. Do you by any chance have instructions for orig ami figures. If you do, please send me some. Thanks!


Penny Nom lui répond.
The incline of an exercise machine 2004-02-02
An exerciser pose la question :
This is a question about incline percentage. On an exercise machine if the elevation is raised 3 and one half inches from a level position then what would be the incline percentage?
Penny Nom lui répond.
Angular speed 2004-02-01
Rachel pose la question :
A 4 inch pulley on a motor makes 1500 revolutions/minute. It is connected to an 8 inch saw blade. a. Find the angular speed of the pulley in radians/minute

b. Find the angular speed of the saw in radians/ minute

Harley Weston lui répond.
Logarithms 2004-02-01
A student pose la question :
Where did the word logarithmic come from? Where/whom did it originate?
Harley Weston lui répond.
Pairing boys and girls 2004-02-01
Terri pose la question :
Suppose 7 boys and 7 girls are assigned to work in pairs of one boy and one girl. Explain what equation can be used and how you would use a simpler problem to solve these types of questions.
Penny Nom lui répond.
The vertex of a cone 2004-01-29
Richard pose la question :
Please help me explain to my fourth graders as to why a cone has a vertex even though it does not have any straight edges.
Chris Fisher lui répond.
Intersecting a line and a curve 2004-01-29
Senthil pose la question :
between line and curve how can i find intersection point? could you write me the formula and explanation also sir.
Penny Nom lui répond.
Is a cylinder a type of prism? 2004-01-29
Rebecca pose la question :
Is a cylinder a type of prism?
Penny Nom lui répond.
Order of operations 2004-01-28
John pose la question :

I am trying to find out any information concerning the development of the order of operations. for example, when (why/how) did it become the case that 2 + 3 x 5 =17, rather than 25.

any insight is appreciated. Thank you.


Penny Nom lui répond.
Sin(3x), cos(3x) and tan(3x) 2004-01-28
Jon pose la question :
What is the identity for cos3x, sin3x, and tan3x? In class, we learned double angel identities and were asked to find out the identity to these three trig functions. If you can help, please do. Also, i know that the cos4x- sin4x is the same as cos2x. Is cos8x-sin8x = cos2x also true? Thank you.s
Chris Fisher lui répond.
Sets 2004-01-27
Susan pose la question :
My child has the following problems to solve, and we are puzzled. 1. Compare the subset symbols to the inequality symbols of less than or greater than.

2. If A, B & C are sets such that A has 47 elements, B has 32 elements, and C is a proper subset of B, what can you say about the number of elements in the following sets: A U B? A intersect B? B U C? and B intersect C?

Penny Nom lui répond.
The London marathon 2004-01-27
Nina pose la question :
After a years training, Minnie Midriffe increased her average speed in the london marathon by 25%. By what percentage did her time decrease?o
Penny Nom lui répond.
Ounces into cubic centimeters 2004-01-27
A student pose la question :
how do you convert ounces into cubic centimeters? Ex: how does 12 oz. change into cc.
Penny Nom lui répond.
Three digit combinations 2004-01-27
Kevin pose la question :
how many 3 digit combinations can be made with 0-9. i have been told only 1,000. when i asked jeeves the response was 750 without using any digit twice. i have entered a raffle and received a ticket with 4 sets of 3 digit numbers.
Penny Nom lui répond.
Lead weights 2004-01-26
Jeff pose la question :
I am making a mold for my decoy anchors. I need 10 - 12 lead ounce weights. How would I determine the liquid measurement for that weight? For example if I melted down 10 ounces of lead how many cups would that be or quarter cups etc?

I would like the formula if I could and good instructions on how to use the formula.

Penny Nom lui répond.
Polynomials 2004-01-25
Bruce pose la question :

A polynomial is defined as
Polynomial functions are functions that have this form:
f(x) = anxn + an-1xn-1 + ... + a1x + a0
The value of n must be an nonnegative integer. That is, it must be whole number; it is equal to zero or a positive integer.
The coefficients, as they are called, are an, an-1, ..., a1, a0. These are real numbers.

Questions:

  1. why must n be positive?
  2. what are some historical facts about the evolution of the definition?

Harley Weston lui répond.
|x^2 - 12x| = 8 2004-01-24
Sherre pose la question :
|x2 - 12x| = 8
Penny Nom lui répond.
Bundles of asphalt shingles 2004-01-24
Larry pose la question :
According to my study material 4:12 multiplying factor for shingles is 1.054. The question reads as follows: A building with a floor plan of 3350 sq. ft. and a roof slope of 4:12 will require _______ bundles of standard asphalt shingles.
Harley Weston lui répond.
x^x^x^x^... 2004-01-23
Ryan pose la question :
you have a number say x and it is to the power of x which is to the power of x and so on infinite times like x^x^x^x^x^x^x^... i have to figure out what x is so that the answer is always 2
Penny Nom lui répond.
A counterfeit coin 2004-01-23
Kim pose la question :
You are considering buying 45 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin?
Penny Nom lui répond.
g on Mars 2004-01-22
RC pose la question :
To measure the acceleration on Mars an object is dropped from a height of 160m. It takes 10s for this object to hit the ground. What is the value for g on Mars?g
Penny Nom lui répond.
A game with some strings 2004-01-22
Trudy pose la question :
A boy holds 6 pieces of strings in his hands with the ends protruding above and below. The top ends are tied together in pairs and then the lower ends are tied together in pairs. What is the probabilty that the pieces of string are all joined in one loop?

What is the probability of obtaining two loops? Can you generalise this to solve the problem for 2n blades of grass?

Andrei Volodin and Penny Nom lui répond.
BEDMAS 2004-01-21
Jessica and her mom pose la question :

my mom and I were wondering 2 things.

1. what is the reason for having bedmas.
2. 5+5-4+[6x3-(6+1-3x2) -5+9]


Penny Nom lui répond.
A problem with sets 2004-01-20
Jason pose la question :

Given that the universal set S is the set of all sports fans, and

F={x|x is a football fan}
B={x|x is a basketball fan}
H={x|x is a hockey fan}
a)Describe (F^B)' (f intersect b)' in words
b)Draw a Venn Diagram and shade the region that represents the set of football fans or both basketball and hockey fans.


Penny Nom lui répond.
What is the speed of the automobile? 2004-01-20
Rita pose la question :
An automobile travels toward Nashville from Cookeville. It takes 33 minutes to travel from Cookeville to Manchester, which is a 36 mile distance. If the driver continues at this pace, what is the speed of the automobile?
Penny Nom lui répond.
A parabolic arch 2004-01-19
Teresa and Robyn pose la question :
A bridge over a river is supported by a parabolic arch...arch is 200 m wide at water level...the maximum height of the arch is 80 m..what is the height of the arch measured from a point on the water 40m from the centre of the arch
Penny Nom lui répond.
The product of any n consecutive integers 2004-01-18
Fazia pose la question :
I have to prove that the product of any n consecutive integers is divisible by n!(eg:the product of five consecutive integers is divisible by 5!) It's easy enough to plug in numbers and prove it is true, but i'm finding it difficult to come up with a proper proof.
Claude Tardif lui répond.
Combinations of 12 numbers 2004-01-18
Cheryl pose la question :
I would like to know the total possible combinations using the numbers 1-12. We would also like to know the formula used to calculate the number of combinations.
Harley Weston lui répond.
Cubic yards in a concrete wall 2004-01-18
Danny pose la question :
I am studing for my contractors exam. I am haveing truble with a few questions. I have the answer to the problems but I dont know how to get them my self.
please help

How many cu. Yds. Of concrete are in a wall that is 150' long and 8'4" high an d 8' thick

Penny Nom lui répond.
Some trig problems 2004-01-18
Weisu pose la question :

I have some questions about pre-calculus.

(1) (2(cos(x))^2)+3sin(x)-1=0
(2) sin(x)cos(x)=(1/2)
(3) 3sin(x)=1+cos(2x)
(4) tan(x)*csc(x)=csc(x)+1
(5) sin(arccsc(8/5))
(6) tan(arcsin(24/25))
(7) arccos(cos(11pi/6))
the last problem uses radian measure.


Penny Nom lui répond.
Two consecutive negative integers 2004-01-17
Amanda pose la question :
Find two consecutive negative intergers whose product is 182.
Penny Nom lui répond.
Six letter words 2004-01-17
Debora pose la question :
An anthropologist discovers an isolated tribe whose written alphabet contains only six letters (call the letters A, B, C, D, E, and F). The tribe has a taboo against using the same letter twice in the same word. It's never done. If each different sequence of letters constitutes a different work in the language, what is the maximum number of six- letter words that the language can employ?
Penny Nom lui répond.
Arrays of pennies 2004-01-17
Kathleen pose la question :
How do I create an array of 100 pennies?
Penny Nom lui répond.
Volume of a tube 2004-01-14
Mike pose la question :
where can you find how to get volume of a tube: 3 in across x 3 inch high
5 in across x 5 inch high
same formula for both. ONE will get the other.

Penny Nom lui répond.
3/8 as a decimal 2004-01-13
A student pose la question :
My Math Midterm is tommorow and I am stumped... how do you turn 1 and 3/8 into a decimal... I know the answer is 1.375 but I just copied down what the teacher wrote on the board.
Oh, and what are the three cases of percents?

Penny Nom lui répond.
What is a Fact Family? 2004-01-13
Keisha pose la question :
I am helping my child with his homework. The worksheet we are trying to do ask the child to choose a number from inside of a circle and then one from inside of a triangle and use the number to build a fact family. The title of the worksheet is "Building a Fact Family House". I noticed that Silver Burdett Ginn,Inc. was the publisher of the book the worksheet came from so I was on the website trying to find an answer to my question. My question is "What is a Fact Family?"
Judi McDonald lui répond.
Polynomial division 2004-01-13
Efrat pose la question :

How do we divide the following polynomials?

(x3 + x2 - x + 2) / (x + 2)


Penny Nom lui répond.
Twelve acres 2004-01-13
Heather pose la question :
I am looking at buying a property that includes 12 Acres of land and I am trying to visualize what this size is equivalent to. I have searched your site and figured out how many square feet it is but I was hoping that you could apply 12 Acres to something tangible, like a football field!
Penny Nom lui répond.
Why is the letter J used for the integers? 2004-01-13
Amanda pose la question :
Why is the letter J used to represent intergers as a symbol?
Penny Nom lui répond.
The square footage of an acre 2004-01-12
Paul pose la question :
What is the square footage of an acre of land assuming all four sides are equal in length.
Penny Nom lui répond.
Permutations and combinations 2004-01-11
A student pose la question :
Are there more permutations than combinations for a series of 4-digit numbers with the integers 0-9? Can you illustrate calculations?
Penny Nom lui répond.
Cubic furlongs 2004-01-11
A student pose la question :
1 mile=8 furlongs, how many cubic furlongs in a cubic mile?
Penny Nom lui répond.
Reflex angles 2004-01-09
Sonya pose la question :
My daughter is searching for examples of reflex angles. We already have the hands of a clock but still need another example. Can you help us.
Chris Fisher lui répond.
Geoboards 2004-01-09
Elissa pose la question :
What is a geoboard? I have a young girl in grade eight math who has a math question using a geoboard.
Diane Hanson lui répond.
The area of a lot 2004-01-09
Lea pose la question :

I have a problem. I am interested in purchasing a piece of property which has the following dimensions. It is 259.10 Feet on the north side x 61.20 Feet on the east side x 217.80 Feet on the south side x 196.70 Feet on the west side. It looks like an irregular rectangle shape. How do you figure out the square footage on this irregular sized property, and what is the correct square footage answer.

I have attached a survey map.


Harley Weston lui répond.
Inequalities 2004-01-08
Michael pose la question :
How do you use inequalities in your job and in your everyday life?
Penny Nom lui répond.
Dividing zero by infinity 2004-01-08
Jason pose la question :
What do you get when dividing zero by infinity? Our Calculus teacher was pretty sure that the expression was indeterminate from. However, if this is so...Why? Zero divded by any number (except zero) is zero, true. Any number (except infinite) over infinite is zero. So, why isn't Zero divided by infinite zero. A simpler way if I had 4 potatoes and was to split them among 2 friends, each friend would get 2 potatoes. However, if I had 0 potatoes and split them a infinite number of ways, each person would still have 0. Explain please!
Penny Nom lui répond.
Unusual occurances 2004-01-08
Martin pose la question :
My wife and I have a question about the probability of something that happened to us a few years ago. So far, no one has been able to give me even an approximate answer. On my 32nd birthday, my wife and I went out to eat at local Japanese hibachi style restaurant. At the restaurant, couples/families are sat together around the hibachi where the cook performs a show. There was a fifteen minute or so wait, so my wife and I sat in the lounge waiting for our name to be called. When they called our names for the reservation, this is what happened. The first group called was the Martin family. Then they called the Francis family. We were the next family to be called, the Ashton family. My full name is Martin Francis Ashton! I think the odds of that happening to someone are very unlikely, but it did, and there is more. Next, we were all sat at the same table in that order, "Martin" family, "Francis" family, then us, the "Ashton" family. Again, it formed my full name!
Penny Nom lui répond.
Is zero even? 2004-01-07
A secretary at an elementary school pose la question :
Is zero an even number?
Penny Nom lui répond.
The sides of a circle 2004-01-07
Helena pose la question :
My name is Helena and I am 10 years old. On a resent math exam I was asked the question" How many sides does a circle have?" and I wrote down none. The teacher said the answer was one side.
Chris Fisher lui répond.
Laying decorative bricks 2004-01-07
Duk pose la question :
Loren is laying decorative brick along both edges of the 21-meter walkway up to his house. Each brick is 0.26 meters long. He is placing the bricks end to end. How many bricks does he need to do the job?
Penny Nom lui répond.
Factoring expressions 2004-01-03
A student pose la question :

I'm having trouble factoring expressions that aren't monic. I can do things like x2-9x+8, but problems like 12x2+5x-3 have me stumped.

I also have a question about factoring out common factors. In a problem like x2-18x+81, wouldn't you divide by 9? But what happens to the x2, is it x2/9?
Penny Nom lui répond.

37 with four 4'2 2004-01-03
Myra pose la question :
Using four fours and only four fours to get an answer of 37.
Claude Tardif lui répond.
Solving an equation 2004-01-03
A student pose la question :
the question is to solve and check equations and the question is
2n + 3n + 7 = -41

Penny Nom lui répond.
Making a windmill 2004-01-02
Matthew pose la question :
I am a farmer in Ontario. It has been almost 20 years since high school. I am toying with making a windmill. The output chart for the the old generator I have is shown below. Before I tear it appart I would like to develop a formula from the chart that can predict the output at various speeds.
Penny Nom lui répond.
Four digit combinations 2003-12-31
A student pose la question :
i need all 4 digit combinations using 0-9 please
Penny Nom lui répond.
Fractions 2003-12-31
Jae pose la question :
Replace the question marks with numbers that will make the sentence true.
1.1/3=?/9=?/6
2.?/18=8/12=4/?
3. 3/?=12/?=9/?
4.?/3=?/21=?/7
5. Which problems have more than one possible answer? Why do you think this is so?

Penny Nom lui répond.
A new way to measure randomness 2003-12-31
Stephanie pose la question :

Last year, I did a science project in which I asked, "Which shuffles better, an automatic card shuffler or shuffling by hand?" To measure this I decided the "best" shuffler was the one to become random first. Last year, to measure randomness, I numbered cards 1-52 and had the subjects shuffle them until they broke up the rising sequences or reached 10 shuffles. (Usually 10 shuffles came first...) Anyway, I did the same thing with the automatic card shuffler, and, as hypothesized, the automatic card shuffler randomized the deck first.

This year, I have decided to continue the project. The problem is, I need a new way to measure randomness without the use of fancy computers or something. I have searched the Internet, I have posted my query on websites based on math, and I have searched the local library.

I have found many useful things on the Internet, but none of them can tell me a new way to measure randomness. I cannot do a perfect shuffle, and I am not terribly gifted in the art of using computers. If you have any information (anything will help) or advice, I would be greatly obliged.


Andrei Volodin lui répond.
The trapezoidal rule 2003-12-31
Prashanth pose la question :
I have a set of XY co-ordinates(say 49 points),I want to find the area enclosed by the curve joining them and the axes.I do not have an equation for the curve and I am not able to fit a curve given the points.I use the trapezoidal rule (Y1+Y2/2)*(X2-X1), Is it right? can I do this with any other method?
Penny Nom lui répond.
Ratios and proportions 2003-12-31
Frank pose la question :
I would like to know how you use 'ratios and proportions' in everyday life.
Penny Nom lui répond.
Some number problems 2003-12-24
Shruthi pose la question :
1. Write 31 using 3 five times
2. Write 100 using all the 10 digits just once
.
.
.

Penny Nom lui répond.
Percent increase 2003-12-24
Frank pose la question :
How does one figure the percent of increase or decrease in the cost of an item?
Penny Nom lui répond.
Making a cone 2003-12-22
Tracie pose la question :

I am working on a craft project at home and I have been given the following information:
16" tall and 13" diameter at base, with 1 and 1/2 " opening at top.

Is there a basic formula for creating a cone with this info?


Claude Tardif and Penny Nom lui répond.
400, 100 and 2500 2003-12-21
A student pose la question :
A person likes 400 but dislikes 300
He also likes l00 but dislikes 99
He also likes 2500 but dislikes 2400

Which of the following does John like
900, 1000, 1100 or 2400


Penny Nom lui répond.
The angles in a regular polygon 2003-12-21
Ernie pose la question :
If i have a measure of one interior angle of a polygon, how can i find the number of sides it has?
Penny Nom lui répond.
Adding percentages 2003-12-19
Paula pose la question :

How do you add percentages

e.g 90% + 80% + 60% + 54% + 25% = ?


Penny Nom lui répond.
Business trip 2003-12-19
Ameer pose la question :
A businnessman drives from Washington, D.C., to Boston, a distance of 442 miles, and then makes the return trip. On the way to Boston, he drives 65 miles per hour, taking an 1-hour rest stop during the drive. After finishing his business in Boston, he make the return trip driving at 60 miles per hour and takes a 45-minute rest stop halfway through the trip. Which leg of the journey, Washington, D.C. to Boston, or Boston to Washington, D.C., takes the longer time?
Penny Nom lui répond.
The area of a plot of land 2003-12-19
David pose la question :
I have a plot of land that I cannot find the square footage of. Actually my home sits on a large lot. Local building codes require that a home is seated on no less than 7500 square feet of land and have no less than 50ft of road frontage (the rear of the lot has 65ft of frontage on another road). I need to know if I have enough square footage to build a second home on the rear lot. The lot has five sides. Only one angle is a 90 deg. angle. The others I cannot determine. Of the 4 remaining angles, all 4 angles are obtuse, or greater than 90 deg. The dementions are 89.19' x 130' x 118.52' x 65' x 170.94'. The two legs that make the 90 deg angle are 89.19' and 170.94'. The measurements fall in order using the 90 deg angle as the point of origin and proceeding clockwise, 89.19', 130', 118.52', 65', 170.94'. I have used all the skill I can muster, however, it has been a long time since school and regretably I cannot find an answer.
Penny Nom lui répond.
Multiplier and multiplicand 2003-12-17
Karen pose la question :
The K-5 curriculum states that at a grade 5 level students should "understand and use the terms multiplier, multiplicand" The curriculum defines 'multiplicand' as " a number being multiplied by another number. A factor." There is no definition given for 'multiplier' Question: Define these words- are they just other words for 'factors'. If so, how important is it that students use these terms? It would seem like 'factors' would be the better choice of words to use. If multiplcand refers to eg. the first factor in the equation and the 'multiplier' the seond term, (if in fact it does)- is this not confusing for students when we teach them that multiplication is commutative?
Penny Nom lui répond.
Binomial distribution 2003-12-17
Lesley pose la question :
my daughter is having difficulty with the following formula P(X=x) = ( n over x) px (1-p) n-x
The teacher has given them the formula but not taught them how to apply it or understand it.

Penny Nom lui répond.
The hour hand and the minute hand 2003-12-17
Minnie pose la question :
When you are looking at the clock at 12:00 the hour hand and minute hand are exactly together. (one on top of the other). Between 1:00pm and 1:15pm there is another time when the hour and minute hands are exactly together again.
Penny Nom lui répond.
Factoring in 2003-12-16
Priscilla pose la question :
How can you use solving by factoring in real life applications?
Harley Weston lui répond.
An elliptical race track 2003-12-16
Judy pose la question :
the inner rail of a race track is a perfect ellipse. the track is a standard width all the way around. how can i prove that the outer rail is a ellipse?
Penny Nom lui répond.
How far can you see? 2003-12-15
Judy pose la question :

How far apart, assuming no obstacles, can two people stand and still see each other?

i know this deals with the curvature of earth, but i can't figure out the formulas involved.


Chris Fisher lui répond.
(2^ 20,966,011) - 1 2003-12-12
Reid pose la question :
Can someone please explain, answer and/or solve this: (2^ 20,966,011) - 1

I don't know what it means, my boss sent it out, I'm assuming it is to be solved but don't know what it is, any prompt help would be appreciated, very much so, in fact, thanks,...........


Penny Nom lui répond.
Math jobs 2003-12-12
Veronica pose la question :
Do you know a couple of jobs I can get when I am older in Math?
Harley Weston lui répond.
A snowball melts 2003-12-11
Adam pose la question :
A spherical snowball has diameter 10cm and density 0.75g/cm3. It is placed in a cylindrical can with diameer 12cm. After the snow melts it turns to water with density 1.0g/cm3. What will be the depth of the water in the can (to 1 decimal place)?
Penny Nom lui répond.
Diamonds and Pearls 2003-12-11
Lauren pose la question :
A crown holds a total of 3080 jewels.
It is made up of diamonds and pearls.
There are 10 times as many diamonds as there are pearls.
How many pearls are there?

Penny Nom lui répond.
1/0 = ?? 2003-12-09
Lisa pose la question :
One of my students asked me a fractions question. She knows that 0/1 equals 0 but does 1/0 also equal 0?
Walter Whiteley and Penny Nom lui répond.
Non-euclidean geometry 2003-12-08
Geoffrey pose la question :
How can you use non-euclidean geometry to navigate on a sphere? What geometers did work in this area?
Chris Fisher lui répond.
Matrices 2003-12-05
Julie pose la question :
I am doing a project and need to find some mathematiciens who had an influence in matrices. I can't seem to find any when I search online. Could you please help me with this?
Judi McDonald lui répond.
Prescription drug coverage 2003-12-04
Khadijah pose la question :
Last week congressional approval was given to legislation involving prescription drug coverage for seniors. One summary of the legislation explains that it is estimated that in 2006 a senior will pay a premium of $35 per month, then pay their first $250 in pharmacy bills. After the bills reach $250, the coverage would pick up 75% of their bills that bring their total bills between the $250 and $2250 mark. After their bills reached a total of $2250, the senior would be responsible for all bills bringing their total annual bills between $2250 to $5100. Then any bills after the $5100 mark has been reached will be 95% covered by the insurance. Using this information, letís analyze the situation of a senior who accumulates $6000 in pharmacy bills over one year and has the insurance coverage. Over the course of this year, how many dollars will the senior pay?
Penny Nom lui répond.
What percentage of 6 billion is 40 million? 2003-12-03
GiGi pose la question :
What percentage of 6 billion is 40 million?
Penny Nom lui répond.
The median 2003-12-03
Christiane pose la question :
how do you find the median of this group of numbers:63,75,29,37,49?
Penny Nom lui répond.
Non-Euclidean geometry 2003-12-03
Geoffrey pose la question :
What are the applications of Non-Euclidean geometry (especially hyperbolic and spherical)?
Walter Whiteley lui répond.
Four digit combinations 2003-12-02
Deen pose la question :

Question:
i have 3 numbers and i have to come up with all the possible 4-digit combinations with those 3 numbers. Is there a formula for it?

Example:
given numbers are 1-2-9 and you need to break a 4 digit code. what are the posiible combinations that u can come up using the 3 numbers?


Penny Nom lui répond.
A locus 2003-12-02
Tash pose la question :

Question:

a)Find the equation of the locus of the point P which moves so that its distance from A(1,2) is always three times its distance from B(5,6)

b) Show that this locus is a circle and states the coordinates of its centre and the length of its radius


Penny Nom lui répond.
Finding angles 2003-12-02
Jason pose la question :
I AM TRYING TO SOLVE A TRIG PROBLEM AND HAVE FORGOT HOW TO DO IT. WHAT I HAVE IS A RIGHT TRIANGLE WITH SIDE A BEING 14 FEET AND SIDE B BEING 3 FEET, USING PYTHAGOREAMS THEOREM SIDE C SHOULD EQUAL 14.318 FEET ON A RIGHT TRIANGLE BUT I AM TRYING TO REMEMBER HOW TO FIND MY ANGLES OTHER THAN THE ONE THAT IS 90 DEGREES.
Penny Nom lui répond.
The area of a triangle 2003-12-01
A student pose la question :
Find the Area of Triangle ABC
A(-3,2)
B(4,0)
C(0,8)

Penny Nom lui répond.
Room and board fees 2003-11-29
Jennifer pose la question :
A certain university wishes to determine room and board fees for the next academic year. For the current year, the fee is $3600 per student and 1800 students are living in the residence halls. Past data suggests that for every $300 increase in the semester fee, 200 fewer students will choose to live in the dorms. There are also costs to the university associated with the residence halls. The fixed costs total $2,000,000 per semester. the variable costs are currently $1000 per student but will fall $100 per student for each decrease of 100 students. Your task is to help the university determine the optimal fee. Assume linear relationships between the number of students and the fee and between the number of students and the cost per student
Penny Nom lui répond.
5.75 acres of land 2003-11-28
Susan pose la question :

We own 5.75 acres of land here in El Paso Tx. Some one wants to buy all or some of our land...to build homes on...but.. I can't figure a few things

1. our land is Almost exactly 500x 500x500 x500 ft square proprty based on this can you tell me the approx perimiter measurements of EACH acre we wish to sell approx 1/2 of this 5.75 acres ...or a tad bit less.. these are all approx measurements what I also need to know is.. how many 50ft x 100ft lots are in each (1 )Acre???


Penny Nom lui répond.
A fish tank 2003-11-26
Bill pose la question :
How do I work out the volume and weight of water in a fish tank that is 36in x 14in x 12in?
Penny Nom lui répond.
Mr.Carter is very cautious 2003-11-26
Bob pose la question :
Mr.Carter is very cautious. He decides to invest in only three stocks: one low stock, one high stock, one medium stock. Given that the expected annual yields are 6% for low stock, 7% for medium stock, and 8% for high stock, he wants his investment in medium stock to be half of his total investment in low and high stock. How much should I invest in each type fo stocks to expect a total annual return fo $650 form my investments?
Harley Weston lui répond.
Area of an equilateral triangle 2003-11-25
Jared pose la question :
Can you help me understand why the area of a equilateral triangle is the square root of 3 divided by 4 times the lenght of the side squared?
Penny Nom lui répond.
An inequality whose solution is all points 2003-11-25
Katie pose la question :

Hi my name is Katie and I am in the 9th grade and I would like help on this question. Is it possible to have a system of inequalities whose solution is all points?

1.I need to know why (explanation)

2.how to do it(example)


Penny Nom lui répond.
The volume of an irregular tetrahedron 2003-11-24
Peter pose la question :
How do I calculate the volume of an irregular shaped tetrahedron where:-
side a = 1.4 m
side b = 1.4 m
side c = 1.2 m
and height = 0.75 m at the junction of sides a and b.

Penny Nom lui répond.
Markup, profit and margin 2003-11-24
Ali pose la question :
I have question regarding Margins, Markups and Profit Purchase price = $ 10.00
Margin or Markup ?? = 40 %
Therefore Selling Price = 10/0.6 = $ 16.67
Profit ? = (16.67-10)/10 *100 = 66.67%
or is the profit = (16.67-10)/16.67*100 = 40 %
Can you please clarify What is Margin, Markup and Profit

Penny Nom lui répond.
Difference of squares 2003-11-24
Susie pose la question :

Factor assuming that n is a positive #

Problem: (I will give it to you in words beacuse I don't know how to do exponents on the computer.) Forty-five r to the 2n power minus five s to the 4n power. I was hoping you could walk me through it not just give me the answer.


Penny Nom lui répond.
An octagon shaped bed frame 2003-11-23
Trish pose la question :
My son and I are making an octagon shaped bed frame. We are going nuts trying to figure out what angle to cut the boards to make an outline of an octagon. It seems that the 8 inside angles of the 8 "corners" are 120*, but what is the angle that the 2x6 wood should be cut so that they will angle together to form the outline of the octagon?
Penny Nom lui répond.
Laws of sines and cosines 2003-11-23
A parent pose la question :
On the one side of a stream lines PA= 586.3 feet, PB = 751.6 feet are measures, angle APB being 167 degrees and 36 min. Q is a point on the opposite side of the stream. Angle PAQ=63 degress and 18 min and PBQ=49 degrees and 24 min. Find PQ.
Penny Nom lui répond.
The volume of a cube 2003-11-22
A student pose la question :
i have a cube, and the line that cuts threough the middle of the cube across to the other side is 4 radical6. what is the volume of the cube?
Penny Nom lui répond.
Aristotle 2003-11-21
John pose la question :

I would like to know how aristotle was related to math.

In all my searches I have found only philosophy etc. But not any math.


Penny Nom lui répond.
AB/AP=AP/PB 2003-11-20
James pose la question :
My name is James McBride. I'm having a difficult time with a pre calculus problem, which goes as follows: "show that AB/AP=AP/PB is equal to (1+5^1/2)/2 (one plus the sqaure root of five with the sum divided by two. I can't do the square root sign, sorry.) I have tried to solve for PB in terms of the other varialbles and then work the quadratic equation. THAT DOES NOT WORK!!!! I am befuddled. Please help me. I am a student of secondary level.
Penny Nom lui répond.
Four digit numbers 2003-11-20
Rob pose la question :
Hello, I sure hope you can answer this question. I got into a discussion at work about how many possible combinations there are for a four digit number using the numbers 0 through 9. This was in reference to a discussion about the lottery. I said there was only 10,000 possible combinations. My friend said that there was many times more, but he could not remember how to figure it out. The answer and the formula would be greatly appreciated.
Penny Nom lui répond.
962 Sq. Ft. is what percent of 2656 Sq. Ft 2003-11-20
Jon pose la question :
962 Sq. Ft. is what percent of 2656 Sq. Ft
Penny Nom lui répond.
4(r-2) = r(2+8) 2003-11-20
Angela pose la question :
I not going to give you the problem that I have, but a problem like it. 4(r-2) = r(2+8) I get mix up trying to solve a problem like this could you help me. So that I will be able to handle the ones on my homework.
Penny Nom lui répond.
A riddle 2003-11-19
Sarah pose la question :
Ok, our teacher gave us this riddle, and I cannot for the life of me figure it out. He said that there are three problems with the following proof:
Penny Nom lui répond.
Systems of equations 2003-11-19
Scott pose la question :

I hope that u can help me....I am a college student taking a class in Pre Calculus.....I have homework due this Friday and it counts a BIG Percentage on my FINAL grade.....I am getting mixed up and can not figure out a few problems.....Please help me.....

Method Of Subsitution

Problem 1. y- 8x = -5
x(squared) + y(squared) = 25

Problem 2. y = x(squared) - 2x - 6
Y = x(squared) - 4

Penny Nom lui répond.

A point and a line 2003-11-19
Meenakshi pose la question :

Given a line segment L(x1,y1) to (x2,y2) and a Point P(x3,y3).
I need the formula to find a point on the line L that is closest to the point (x3,y3).


Penny Nom lui répond.
If 1 is neither prime nor composite... 2003-11-19
Joshua pose la question :
if 1 is neither prime nor composite...what is it called?
Claude Tardif and Penny Nom lui répond.
If 1 is neither prime nor composite... 2003-11-19
Joshua pose la question :
if 1 is neither prime nor composite...what is it called?
Claude Tardif and Penny Nom lui répond.
Unmatched socks 2003-11-17
Shannon pose la question :

i have 6 pairs of socks lying unmatched in my dresser drawer. Each pair is a differnt color (brown, black, red, yellow, green, purple) When i wake up in the morning, I randomly grab 2 of the loose socks and put them on without looking.

If two socks are randomly selected from the drawer, what is the probability that they match?


Andrei Volodin lui répond.
The 4th difference 2003-11-17
Jack pose la question :
If i had a sequence which was the same at the 4th difference, aka difference to the 4th, like:

1 5 14 30 56 96 (sequence)
4 9 16 26 40
5 7 10 14
2 3 4
1 1

then what would be the set formulars to find out a, b, c, d, and e
as i know the equation has to be an4+bn3+cn2+dn+e

Penny Nom lui répond.
Adding fractions 2003-11-16
Ken pose la question :
My name is Ken and I am taking my GED course for my High School and have not been in a class for 35 years. I am doing this for re-training. I am at the part about fractions. Here is an example that I am having trouble with.

1 3/7 + 4 2/3 + 11/21

They have no common denominators. Could you PLEASE help me. If you could send me a step by step explanation it would be greatly appreciated.

Penny Nom lui répond.
Three problems 2003-11-16
Megan pose la question :
My name is Megan and I am a junior in high school. Our teacher gave us a few xtra credit questions and I need some help.
Penny Nom lui répond.
Divisibility by 7 2003-11-14
A student pose la question :
how do you test a number to see if it is divisible by 7 or not?
Penny Nom lui répond.
Lines 2003-11-14
A student pose la question :
What is a name that a group of lines pass through?
Chris Fisher lui répond.
root24 = 2 root6 2003-11-13
Burke pose la question :
I know that all algerbra can be represented visually, for example: Y=9x+3 is a line on a two dimentional plane. Could Math Central please send me a visual representation of the proccess of simplifying square root like root24 equals 2root6
Penny Nom lui répond.
Diagonals in an octagon 2003-11-13
Glenn pose la question :
Question 1.
What is the probability of choosing the longest diagonal in an octagon?

Question 2.
Probability of choosing the shortest?
Andrei Volodin and Penny Nom lui répond.

A trig identity 2003-11-12
A student pose la question :
I can't prove this identity. Can you please help me?
(1-tanx)/(1+tanx)=(1-sin2x)/(cos2x)

Penny Nom lui répond.
What is a number that has exactly 13 factors? 2003-11-09
Mary pose la question :
What is a number that has exactly 13 factors?
Penny Nom lui répond.
Mixing Brazil nuts and cashews 2003-11-09
Bob pose la question :
Cashews are sold for 1.20 per 1/4 pound and Brazil nuts are sold for $1.50 per 1/4 pound. If you mix 20lbs of Brazil nuts, how many cahsews would it take to make a mix that sells for $1.30 per 1/4 pound?
Penny Nom lui répond.
A least squares line 2003-11-09
Michelle pose la question :
Hooke's Law asserts that the magnitude of the force required to hold a spring is a linear function of the extension e of the spring. That is, f = e0 + ke where k and e0 are constants depending only on the spring. The following data was collected for a spring;

e: 9 , 11 , 12 , 16 , 19
f : 33 , 38 , 43 , 54 , 61

FIND the least square line f= B0 + B1x approximating this data and use it to approximate k.
Penny Nom lui répond.

Greatest Common Factor 2003-11-08
Beth pose la question :
How do you use the Greatest Common Factor in addtion and subtraction of fraction?
Penny Nom lui répond.
Equal ratios 2003-11-07
A student pose la question :
In the ratio 3:8=17__, can__be a whole number?
Penny Nom lui répond.
The product of the page numbers 2003-11-07
Morgan and Mom pose la question :
You open a book and the product of the page numbers is 12,656. What are your page numbers?
Penny Nom lui répond.
Chisenbop 2003-11-06
Jaclyn pose la question :
Hi there i was wondering if you would have any information on "counting on your fingers" or " Chisabop".
Penny Nom lui répond.
Intercepts 2003-11-04
A student pose la question :
I am totally confused on how to determine intercepts of an equation and then to graph the line. For example, how to determine the intercepts of 2x-3y-12=0.
Penny Nom lui répond.
X bar 2003-11-04
mary pose la question :
Remind me what this means:

    _    
    X 

Andrei Volodin lui répond.
The length of a chord 2003-11-03
David pose la question :
When Radius=400.00' and Arc=130.58' what is the Cord distance in feet?
Penny Nom lui répond.
A circle around an irregular polygon 2003-11-03
Dale pose la question :
How do I find the properties of a circle that is drawn around an irregular polygon of (n) sides with the lenghts of each side given and all end points of the polygon lye on the circumferance of the circle?
Chris Fisher lui répond.
Solve for Q 2003-11-03
Anwaar pose la question :

The problem is:

QT - X
________ + H = HT
QS


Peny Nom lui répond.
Cubic yards of concrete 2003-11-02
John pose la question :
The foundation is 20' X 20' and the depth is 6", there are also three footings that are 20' X 12" X 12" each. Can you show me the equation to figure out how many yards of concrete I will need to pour the footings and foundation.
Harley Weston lui répond.
Symmetries of a rhombus 2003-11-02
Tonia pose la question :
why cant an equal sided rhombus have 3 lines of symmetry? you have one line of symmetry on each of the diagonals, and there should be one vertically on an angle. can you please explain the rules of symmetry to me?
Walter Whiteley lui répond.
Which one has the most factors? 2003-10-31
Kristi pose la question :
Of all the whole numbers less than or equal to 5000, which one has the most factors?
Claude Tardif lui répond.
Divisibility by 2 or 5 or both 2003-10-30
Abdu pose la question :
How many positive integers less than 1,001 are divisible by either 2 or 5 or both?
Penny Nom lui répond.
1/x + 1/y = 5/12 2003-10-30
Ben pose la question :
1/x +1/y =5/12, what is the sum of x and y?
Penny Nom lui répond.
12 cookies 2003-10-29
Joel pose la question :
there are 12 chocolate, sugar and cinnamon cookies. the probability of choosing a chocolate cookie is 1/3. the probability of choosing a sugar cookie is 1/4 what is the probability of choosing a cinnamon cookie
Penny Nom lui répond.
A rectangle on a disk 2003-10-29
Arthur pose la question :
How do I go about solving the following problem: What is the width of the largest rectangle with a length of 16 inches you can cut from a circular piece of cardboard having a 10 inch radius?
Penny Nom lui répond.
How much time? 2003-10-29
Lori pose la question :
I am a elementary teacher 3-6 math. We have just implemented the Houghton Mifflin Math curriculum. It seems to be quite difficult for most of our students. In order to get through all the material we need to do a lesson a day. Although the students are not getting the material that fast. Should we move on without all the students understanding the material or should we wait and remediate until they get it and be behind for the year. This isn't just a few kids its most of the kids. We are also suppose to teach to all the standards so if we don't get to them the students will not do well on the standardized tests.
Diane Hanson lui répond.
Trees 2003-10-28
Ali pose la question :
Is there any formula for counting the number of trees (graphs)?
Denis Hanson lui répond.
Means 2003-10-28
Abdu pose la question :

Question:
80,80,84,85,88,92,97,98

The average of the 8 numbers listed above is 88. Of the following which pair of numbers could be removed from the list without changing the average.

A. 80 and 97
B. 80 and 98
C. 84 and 92
D. 84 and 97
E. 85 and 92

Andrei Volodin and Penny Nom lui répond.
Solve for x 2003-10-27
Lonnie pose la question :
i need help with solving equations and formulas such as -3x+b=6x, for x. I do not understand how you find x.
Penny Nom lui répond.
Knitting gauge and felting 2003-10-27
Sara pose la question :

I wish to create a pattern to knit an item that will then be felted, thus, shrink as a result. In order to determine the proper gauge to use in creating the item, I produced a gauge swatch, noted the original properties and then the post-felting properties. They are as follow:

Before Felting:

20 stitches(width) x 20 rows(height)yielded:
Gauge: 3.2 stitches(width) and 4 rows(height) = 1"
Dimensions: 6.25"(width) x 5.25"(height)

After Felting:

20 stitches(width) x 20 rows(height)
Dimensions: 4"(width) x 3"(height)

How do I calculate the percentage change in size to accurately determine the number of stitches and rows needed to produce the desired dimensions for the finished (felted) item?


Penny Nom lui répond.
A rock on a string 2003-10-26
A student pose la question :
a rock on a 4' string is rotated at 80 rpm. what is the linear speed in feet per second? in miles per hour?
Penny Nom lui répond.
Maine and Nevada 2003-10-24
Jimmy pose la question :

From 1989 to 1990, the population of Nevada increased b y 157,000, and that of Maine increased by 30,000. In 1990, the population of Nevada was 1,206,152, and that of Maine was 1,233,223. If the populations of the two states continue to increase at the same rates, when will the populations of Nevada and Maine be the same?

Write a verbal model for this problem
Write an equation for the model
Solve the equation and answer the question.


Penny Nom lui répond.
A parabola 2003-10-24
Delores pose la question :
Given the vertex (4, -2) y intercept = -6 find if/where the parabola crosses the x axis?
Penny Nom lui répond.
0.810 and 0.801 2003-10-24
Ahmed pose la question :

could you please tell me what is the greatest decimal fraction formed of the digits 0, 1 , 8?

Is it 0.810 or 0.801, please give me the reason of the answer in details and the references if it possible.


Penny Nom lui répond.
Odd Pythagorean triples 2003-10-23
Kathleen pose la question :
in a triple can a and b be odd numbers
Penny Nom lui répond.
Arithmetic in bases other than 10 2003-10-22
Kim pose la question :
how do you add, subtract, multiply and devide in base 3, base 5, etc?
Penny Nom lui répond.
Squares in a rectangle 2003-10-21
Raj pose la question :

Draw a rectangle with sides of 3 and 4. Divide the sides into 3 and 4 equal parts respectively. Draw squares joining the points on the sides of the rectangle. You will have 12 small squares inside the 3 x 4 rectangle.

If you draw a diagonal of the rectangle, it will intersect 6 of the the 12 smaller squares.

Similarly, if you have a 4 x 10 rectangle, the diagonal would intersect 12 of the 40 squares inside the rectangle.

Is there an algebric equation that determines the number of squares that will be intersected by the diagonal of a rectangle?


Chris Fisher lui répond.
0.3 trillion 2003-10-20
Bill pose la question :
What is .3 of one trillion?
Penny Nom lui répond.
Domain of a function 2003-10-14
Karim pose la question :
Find the Domain of the Function
H(x) = Log3 (4x + 7)-10
H(x) = log base 3 times 4X plus 7 minus 10
i am having problem solving these kinds of problems.

Penny Nom lui répond.
Pairs of prime numbers 2003-10-13
Nikolas pose la question :
Use pairs of prime numbers to find all the numbers less than 50 that have only two prime factors. Make an organized list.
Penny Nom lui répond.
5x - y 2003-10-11
Candace pose la question :
math problem 5x-y for x=12 and y=14 do you mulitilpy 5x12 and than -the answer from 14 which gives you 46? is this right
Penny Nom lui répond.
Points inside a triangle 2003-10-10
Laura pose la question :

is there a way to establish, if a given point at coordinates (x,y) is within an area defined by three other sets of coordinates forming a triangle ABC?

is T(x,y) within triangle A(x,y)B(x,y)C(x,y)


Chris Fisher lui répond.
Statistics from grouped data 2003-10-09
Rebecca pose la question :

I have to use a suitable computer package (ie. Excel) to work out the mean and standard deviation of the following:

 Price Range            No of Houses        No of Houses 
£`000                  Area 1              Area 2   

45 and under 50         4                   5 
50 and under 55        7                   12 
55 and under 60        14                  16 
60 and under 70        19                  18 
70 and under 80        8                   3 
80 and under 100       5                   2 

I have used excel to work out mean and standard deviation before, but not in a more complicated example like this.

Any advice on where to start would be greatly appreciated.


Penny Nom lui répond.
10,000 2003-10-08
Nathan pose la question :
what two numbers make the product of 10,000. Neither number can end in a zero
Penny Nom lui répond.
Interest compounded daily 2003-10-08
Terie pose la question :
If I owe $2000.00 @ 6.25% compounded daily for 54 days. How much do I owe in interest?
Penny Nom lui répond.
Standard Deviation 2003-10-07
Rebecca pose la question :

I have a task to complete, which is to calculate the mean and standard deviation of something. I have done this but am then asked to write a short explanation of my findings.

I know what the mean is about, and I thought I knew what the standard deviation meant too - shows the variation from the mean. However, on a task I completed earlier the feedback I got said 'you need to tell us that it is talking about the middle 66% of the data' - that has thrown me, I don't understand that. Can anyone help me get my head round this???


Penny Nom lui répond.
Two chords 2003-10-07
Lori pose la question :
Chords AB and CD of circle O intersect at E. If AE=4, AB=5, CE=2, Find ED.
Penny Nom lui répond.
The sketch of a graph 2003-10-07
A student pose la question :
I was wondering how do you figure out if a graph has a horizontal tangent line. One of my homework problem was to sketch the graph of the following function; (4/3)x3-2x2+x. I set f''(x) ( the second derivative) of the function equal to zero and got the inflection point:(1/2,1/6). Also i am having trouble finding the concavity for x>1/2 and x<1/2, i am getting a different answer from the back of the book, the graph i draw looks completely different from the correct answer.
Penny Nom lui répond.
Arrangements around a circular table 2003-10-07
Lori pose la question :
How many arrangements can 6 people be seated round a circular table?
Penny Nom lui répond.
Indeterminate forms 2003-10-06
A teacher pose la question :
Is it possible for me to find any geometrical interpretation without using calculus to explain indeterminate forms?
Chris Fisher lui répond.
Functions, graphs and derivatives 2003-10-05
Jathiyah pose la question :
I wanted to know how would you tell (on a graph diplaying two funtions), which funtion is the derivative of the other?
Walter Whiteley lui répond.
The slope of a tangent 2003-10-01
A student pose la question :

find the slope of the tangent to each curve at the given point

f(x)=square root 16-x, where y=5


Penny Nom lui répond.
A rectangle in a circle 2003-09-27
Abdu pose la question :
A rectangle ABCD is inscribed in a circle. If the length of AB is 5 and length of BC is 12, what is the area of circle outside the rectanlge ABCD?
Penny Nom lui répond.
Relatively prime 2003-09-27
James pose la question :
what is the definition a relative prime numbers?
Penny Nom lui répond.
0/0 2003-09-25
Thomas pose la question :
How is 0/0 ever defined.
Penny Nom lui répond.
Absolute value 2003-09-23
Crystal pose la question :
I am trying very hard to understand Absolute Value, and I cannot seem to grasp the idea. I do not know why we use it, what the point of it is. I do not know how to use it. I know that it is always positive or zero, and I assume it relates to distance, but how can you use it in equations. Please explain it to me as simply as possible, thank you.
Walter Whiteley lui répond.
The golden ratio 2003-09-23
Phillip pose la question :
The Golden Section can be made from an equilatereral triangle inscribed within a circle. The Golden Section is achieved by joining the mid points of two arms of the triangle to the circumference. I can prove this by erecting a perpendicular to the line outside the circle, but am interested to see how it can be proved from within the circle.
Chris Fisher lui répond.
Primes 2003-09-23
Julie pose la question :

#1. Suppose you are given a number (n) and told that 1 and the number (n) divide into (n). Does that mean (n) is prime?

#2. Suppose that p is a prime number greater than or equal to 3. Show that p+1 cannot be a prime number.


Penny Nom lui répond.
The Sieve of Eratosthenes 2003-09-18
Lynn pose la question :
My daughter has been asked to find all the prime numbers by using the Sieve of Eratosthenes. I have no understanding what this means.
Penny Nom and Claude Tardif lui répond.
1 + 1 = 10 2003-09-17
David pose la question :
could you please explain to me how 1+1=10 thanks
Penny Nom lui répond.
Applications of logarithms 2003-09-16
A student pose la question :
I have a project due in my algebra two class dealing with logs and where they are used in life, but I am having trouble finding websites that relate. So I would really appreciate it if you couldhelp me.
Penny Nom lui répond.
Notation 2003-09-15
Kim pose la question :

Question:
i have a couple of questions

1. write in standard form
a)4x2x8 b) 5 to the power of 4

.
.
.

Penny Nom lui répond.
Substitution method 2003-09-14
John pose la question :

Hello, my name is john and while I was finishing up my work I stumbled into these problems. a/4-b=-1
a+b=11
and
6a-b=-5
4a-3b=-8

Thanks a lot. I really need some help :)
John


Penny Nom lui répond.
The volume of an earthen pit 2003-09-12
Bruce pose la question :
This shape would occur at the four corners of a rectangular shaped earthen pit with sloping sides (1:1.5). Depth is 14'. Top dimensions are 170' by 158'. After calculating the easy volume components of this shape, we are left with the end corner pieces. 21' base, 14' height, side hypotenuse 25.24' and corner diagonal 32.83'. We're confused. Thank you for any help you may provide.
Penny Nom lui répond.
The digits in 349 2003-09-12
Franik pose la question :
in the number 349, which number has the least value, and why?
Penny Nom lui répond.
Two line segments and a plane 2003-09-11
Laura pose la question :
Do all figures made up of two segments lie in a plane?
Penny Nom lui répond.
Area of a rectangular room 2003-09-11
Kelly pose la question :
The area of a rectangular room is 238 square feet. The width is 3 feet less than the length. What are the dimensions?
Penny Nom lui répond.
The general equation for a sphere 2003-09-11
Jaidev pose la question :
Is there any general equation for a sphere?
Penny Nom lui répond.
The mean house price 2003-09-10
Carol pose la question :

Question:
I have to find the mean from the following example:

Price Range £000 No of Houses
55 and under 60 3
60 and under 65 6
65 and under 70 13
70 and under 80 21
80 and under 100 15
100 and under 130 7
130 upwards 1

I know when calculating the mean you use the mid points of the classes, but how does this work for the 130 upwards class? Also, does this still work given the difference in the classes (ie. 1st class is 5, 5th class is 20, etc). Any help to get me started would be greatly appreciated.


Penny Nom lui répond.
Converting from base 10 to base 5 2003-09-10
Susy pose la question :

My son, who is 9 in grade 5 has been asked to convert base 10 numerals into base 5.

His first question of:

24(10) he has calculated to be 4x5 + 4x1 = 44 (5)

The next question however is the tricky one.Ý We know the answer is supposed to be 100 but we find it difficult to get this in the way he understands it.

25 (10) = _________________ 100 (5)

Can you help us figure out how we reach the answer.


Claude Tardif and Penny Nom lui répond.
How high does the sequence of numbers go 2003-09-07
Shayna pose la question :
My quetion is "How high to the sequence of numbers go"?
e.g. one, ten, hundred, thousand, million, billion, trillion, and from there is my queston.

Penny Nom lui répond.
Making a square 2003-09-07
A student pose la question :
if I am given any number (say 80 for example), how may I determine the smallest whole number integer which when multipled by it will yield a square number ? In other words if I express this as: 80Ý*ÝnÝ=ÝsquareÝnumber, what is the least value of n which will yield a square.
Penny Nom lui répond.
Consecutive integers 2003-09-07
Amy pose la question :
I was wondering if there was a proper way to write the solution to a problem requiring consecutive integers? Is it okay to write the solution as 5,4,3,2,1 or must it be written as 1,2,3,4,5?
Penny Nom lui répond.
Order of operations 2003-09-07
Brian pose la question :

It has to do with the 4 rules of operations, Parentheses first before operations outside/evaluate all exponential expressions/all multiplication and divisions/then all additions and subtractions.

Who made these rules and when did they make them,,, I know its somewhat of an unorthadox question but I must know. I would really appreciate it.


Penny Nom lui répond.
7,473,000,000 divided by 52000 2003-09-06
A student pose la question :
I am having trouble with a question. 7,473,000,000 divided by 52000. Our calculater gets 147311.5385. I come up with 143711.53846, and then the number starts to repeat itself
Penny Nom lui répond.
Can 2 vertical planes intersect? 2003-09-06
Erin pose la question :
My question is can 2 vertical planes intersect?
Penny Nom lui répond.
One million seconds 2003-09-04
Vince pose la question :
If you can write a number each second for one million seconds, how many hours would it take?
Penny Nom lui répond.
Four digit combinations 2003-09-04
Emma pose la question :
I seriously need to find out all the four digit combinations from 0 to 9!!! My name Is Emma Dibitt and I'm going into 8th grade and I'm a student!!!
Penny Nom lui répond.
Grooming the king's horses 2003-09-04
Janelle pose la question :
the stable boy had 90% of the kings horses groomed.the next day the king acquired 25% more horses. Now there was 105 horses not prepared for the kings men. How many horses did the king originally have?
Penny Nom lui répond.
A 16 foot ladder 2003-09-04
Kelly pose la question :
Two buildings are separated by a three-foot alleyway. Fatima wants to use a 16 foot ladder to reach a window in the wall of one of these buildings. If she places the foot of the ladder against the base of the other building, how far up the wall will the top of the ladder reach??
Penny Nom lui répond.
One percent of a billion 2003-09-04
Charles pose la question :
What is one percent of one billion?
Penny Nom lui répond.
Positive, negative and zero 2003-09-04
Brian pose la question :
Can the Value of zero be positive or can it be negative or can it be both.
Penny Nom lui répond.
The game of 24 2003-09-03
A student pose la question :
We have a game where four numbers must equal 24 using addition, subtraction, multiplication and/or division.Ý I am stuck on the following four numbers - 12, 24, 9 and 17.
Penny Nom lui répond.
A boat travels 12 km upstream... 2003-09-03
Sohaib pose la question :
A boat travels 12 km upstream and back in 1 hour 45 minutes. If the speed of the current is 3km/hr throughout, find the speed of the boat in still water, giving your answerÝcorrect to 3 decimal places.
Penny Nom lui répond.
Why percentage? 2003-09-03
Vicky pose la question :
My cousin aske me a question about the use of percentages and I'm not sure how to answer it. He wants to know why when there is a sale in a shop we use percentages and not fractions or decimals.
Penny Nom lui répond.
Percentage markup 2003-09-03
Virginia pose la question :

I am confused and hope you can help. I have looked high and low for a "chart" persay to go by when I am having to calculate markup percentages.

Example if I have a List price of $1838.00 and my cost is $955.76 and I want to mark it up 30%. My colleage says it should be divided by .7

I don't understand how he arrives at .7 from 30 percent.


Claude Tardif lui répond.
Profit margin 2003-09-03
Chet pose la question :

My salesman calculates a customers profit margin by dividing what the customer paid by what he sells for, then subtracting that answer from 1. For example a customer sells a product for $15. He bought it for $10. 15/10=.66 Subtract that from 1 and get a profit % of 33%

Here's my question: If I want to figure what a reseller will sell a product for if he wants 40% margin(by the technique above), what formula do I use? Let's say I want to sell a product for 8.50, and I want the reseller to make 40%


Penny Nom lui répond.
Two row arrays 2003-09-03
Madalyn pose la question :
My question is, what are #'s that can not be arranged in two row arrays called?
Penny Nom lui répond.
A helicopter rises vertically 2003-09-02
Kate pose la question :
A helicopter rises vertically and t seconds after leaving hte ground its velocity is given in feet per second by v(t) = 8t + 40 / (t+2)2 How far above the ground will the helicopter be after 3 seconds?
Penny Nom lui répond.
Water in a tank 2003-09-02
A parent pose la question :
if a tank is 48 inches long 14 inches wide and 18 inches deep if a yardstick was inserted into the tank and measured 2 inches of water in the tank how many gallons of water would be in the tank.
Penny Nom lui répond.
A theorem in geometry 2003-09-02
Diego pose la question :
Please refer to figure in attached file. P is a point on the chord AB of a circle such that the tangent PT which touches the circle at T is equal to AB. How do we prove that PT2 = AP x BP.
Dieter Ruoff and Penny Nom lui répond.
The units digit of 57 to the 28th power 2003-09-01
Maria pose la question :

If 57 is raised to the 28th power, what must be the units digit in the result?

If you raise 7 to the 500th power, what is the numeral that will appear in the units digit position?


Penny Nom lui répond.
A 6 team schedule 2003-08-31
A scheduler pose la question :
I saw that someone put on your web site a team schedule and you helped them figure it out.Ý I have 6 teams that want to play each other once, and believe it or not, I cannot figure it out.
Penny Nom lui répond.
20% of 40% of 500 2003-08-31
A student pose la question :
What is 20% of 40% of 500?
Penny Nom lui répond.
Terminology 2003-08-31
Maria pose la question :
My daughter Veronica is a rising 6th grader and has to complete some Summer Math
assignments and would like to ask you three questions:
  1. ___________ are number pairs that have a product of 1.

  2. You can name any point on a plane with two numbers. These two numbers are called _____________.

  3. A _______________ is the size of a cube that is exactly 1 inch on each edge.
Thanks,

Penny Nom lui répond.
The quadratic formula 2003-08-31
Alex pose la question :
I am using Houghton Mifflin's Precalculus with Limits book, 2nd edition. However, the first chapter encompasses Algebra review, and I am stuck on a problem. All that's required is to solve the following and verify using a calculator:
3y2+6y+2=0
I have solved the problem using the quadratic formula, but from what I remember, the quadratic formula is used in the case of equations following the AX2+BX+C=0 pattern. As the problem I am attempting uses a y-variable, can I still use the quadratic formula? Since I am not sure what route to take in solving this problem, I am hoping you can assist me.

Harley Weston lui répond.
Newton's binomial theorem 2003-08-30
William pose la question :
According to page 126 of Murtha & Willard's "Statistics and Calculus" (Prentice-Hall, 1973), Newton's binomial theorem can proved inductively. I suppose that was his method, which I would like to see.
Penny Nom lui répond.
I can Guess your birthday 2003-08-29
Michelle pose la question :
Hi I am trying to explain to my children how this problem works. It was sent to me on the internet and I can not figure it out. They keep asking me how it works and I can not tell them.

The problem is: "I can Guess your birthday::


Penny Nom lui répond.
How many cubic yards must I purchase? 2003-08-29
Walt pose la question :

I am trying to determine how much top soil I must purchase (by the yard).

The area is 80' x 15' and I want it 3" thick. How many cubic yards must I purchase?


Penny Nom lui répond.
Converting to base 10 2003-08-28
Karen pose la question :
My son is in 5th grade.Ý He is learning how to convert numbers from base 2 to base 10, and base 5 to base 10.Ý Can you explain it to me in the simplest terms?
Penny Nom lui répond.
Graphing a piecewise function 2003-08-24
Amber pose la question :
How do i begin to graph a piecewise function, absolute function or step function?
Penny Nom lui répond.
Simplify 2003-08-24
Jessica pose la question :
I have been asked to simplify the expression (5a2)(-2b2)(3b)+(7a2)(2b2)+(-3a)(-5a)(4b) and the answer is apparently 44(a2)(b2). For the life of me I can't figure out how they derive this.
Penny Nom lui répond.
Why is 5 to the 0 power always 1? 2003-08-24
Crystal pose la question :
Why is 5 to the 0 power always 1?
Penny Nom lui répond.
A rule with a variable 2003-08-24
Crystal pose la question :
what is a rule with a variable
Penny Nom lui répond.
X.9999... and X+1 2003-08-23
David pose la question :
I have read your answers to the questions on rational numbers, esp. 6.9999... = ? and still have a question: The simple algebraic stunt of converting repeating decimals to rational numbers seems to work for all numbers except X.999999.... where X is any integer. The fact that the method yields the integer X+1 in each case seems to violate the completeness axiom of the real numbers, namely that there is no space on the number line which does not have an number and conversely that every geometric point on the number line is associated with a unique real number. In the case of 3.999... for example, it seems that both the number 4 and the number 3.9999.... occupy the same point on the number line. How is this possible???
Penny Nom lui répond.
A golf tournament 2003-08-23
Dale pose la question :
I am running a golf tournament with twelve golfers. We will be playing four rounds of golf. I don't want to schedule the same two players together more than twice (if possible). How would I make a schedule that each player would play at least once with every other player? I would appreciate any help that you can give me.
Denis Hanson lui répond.
A worm on a hill 2003-08-21
Lisa and Samantha pose la question :
A WORM IS AT THE BOTTOM OF A 10 FOOT HILL. HE CRAWLS UP THE HILL 4 1/2 FEET A DAY. AT NIGHT WHEN HE REST HE SLIDES DOWN 2 1/2. HOW LONG DOES IT TAKE THE WORM TO CRAWL UP THE HILL.
Penny Nom lui répond.
Two equations 2003-08-21
Jennifer pose la question :

The following problems have me stuck and any help would be greatly appreciated seeing my text book is doing me no favours:

32a+1 - 283a + 9=0
and
52m - 5m=20


Penny Nom lui répond.
39 consecutive natural numbers 2003-08-19
A student pose la question :
Prove that among any 39 consecutive natural numbers it is always possible to find one whose sum of digits is divisible by 11.
Penny Nom lui répond.
The volume of a fuel tank 2003-08-16
Phil pose la question :
I hope you can help me out with a small problem. My boat has a fuel tank measuring 1680mm long x 630mm wide x 130mm high. Can you tell me how much fuel it will hold in both litres and imperial gallons.
Penny Nom lui répond.
The number of three digit combinations 2003-08-16
Fred pose la question :
There are four close friends having a heated discussion concerning the the number of three digit combinations using the numbers 0 through 9. The discussionÝinvolves the daily lottery.Ý Any assistance you can lend would be greatly appreciated.
Penny Nom lui répond.
Acres 2003-08-13
A landowner pose la question :
Can you please tell me how many total acres the following measurements would equal? 280 feet by 80 feet
220 feet by 70 feet
200 feet by 75 feet

Penny Nom lui répond.
Making a blanket 2003-08-13
Liz pose la question :
Please help me figure this out. I am making a blanket the directions call for a piece of material measuring 72"X45". Instead of one piece I'd like to make a patchwork quilt but the squares need to equal 72"X45". Centered on the bottom of the longest edge is an 18" square.
Harley Weston lui répond.
Water in a cone 2003-08-12
Adrienne pose la question :

Water is poured into a tank in the shape of an inverted right circular cone.ð The height of the tank is 8 m and its radius at the top is 4 m.

a. Draw and label a picture to represent this situation.ð (I know how to do this)

b. Identify all variable quantities. (h = 8m, r = 4m)

c. Find an equation that relates the variable quantities, and reduce the number of variable quantities to two.

I was thinking about the equation V = 1/3 pi r2 h, which is the Volume of a cone, but I am stumped as to how I am supposed to "reduce the number of variable quantities to two." Can you point me in the right direction?


Penny Nom lui répond.
Yards and cubic feet 2003-08-11
Sonya pose la question :
How many cubic feet are in a yard?
Penny Nom lui répond.
A sphere inscribed in a cone 2003-08-10
A student pose la question :
A sphere with radius 5cm is inscribed in a right circular cone 20 cm in height.find

(a) the base radius ,volume of the cone
(b)volume of the shaded space( to 3 sig fig)

Penny Nom lui répond.
The side length of a regular octagon 2003-08-09
Rich pose la question :
If I know the distance between the parallel lines of an octagon and want to find the length of the sides, can I just divide that distance by 2.414 to reveal the length of the sides? I work construction and just curious if I am figuring it right.
Penny Nom lui répond.
Liters in a pool 2003-08-05
A parent pose la question :
I need to know how many litres in a 12 foot diameter, 3 foot deep pool? Any help much appreciated as I need to add the correct amount of chemicals
Penny Nom lui répond.
Diagonals in an octagon 2003-08-04
Amanda pose la question :
How many diagonals are in an octagon??? What would be a drawing of those diagonals???
Penny Nom lui répond.
Two precalculus problems 2003-08-04
Kate pose la question :

Please help me verify the identity:
cos2x(sec2x-1)=sin2x

Also I am having trouble withdetermining whether f(x) is odd, even, or neither
f(x)=x3-x


Penny Nom lui répond.
The incline of a road 2003-08-03
A driver pose la question :
incline- % grade as to degree. ie 6% hwy grade= what degree of incline?
Penny Nom lui répond.
Percentage decrease in sales 2003-07-31
Linda pose la question :
If I had sales in January of 2002 that were $42,493.73 and sales that were $37,281.59.Ý The difference is $5374.50.Ý What is the percentage of decrease in sales?
Penny Nom lui répond.
Inserting a comma ever three digits 2003-07-25
Linda pose la question :
when writing a large number, why do we insert a comma every three numbers instead of every two or four numbers?
Penny Nom lui répond.
Cutting some wood 2003-07-25
Betty pose la question :
My husband is building a six sided wood circle and would like to know the angle to cut the pieces.
Penny Nom lui répond.
The area of an odd shaped piece of property 2003-07-24
Barry pose la question :
What is the formula for figuring the square footage of an odd shaped piece of property?
Penny Nom lui répond.
Surface area of a sphere 2003-07-23
Rob pose la question :
I have a shere with a circumference of 12 feet. What is the total surface area of the shere in square feet and how did you find it?
Penny Nom lui répond.
nine digit numbers 2003-07-23
John pose la question :
With a nine digit number, with each of the nine digits having a possibility of 10 different numbers then what is the total number of possible mathematical variations in the nine digit number. i.e. Social Security numbers have nine digits and if each of the nine digits have a possibility of being any one of ten numbers, i.e. 0,1,2,3,4,5,6,7,8,9. Then what is the formula to calculate the maximum possible number of variations in this nine digit number and what is the mathematical maximum possible number of variations of this nine digit number?
Penny Nom lui répond.
Natural logarithms 2003-07-22
Amanda pose la question :
I'm going into my senior year of high school. I will be taking AP calculus, and my teacher gave us some homework over the summer. However, there are two things that I do not understand how to do. The first is, she wants us to be able to generate a unit circle by hand using 30, 60 and 90 degree triangles. I have used the unit circle in trigonometry, however I was never taught how to draw it. Secondly, I need to know how to do natural logarithms without a calculator. I was not taught how to do this, and the worksheet I was given only showed me how to complete them using a calculator.
Claude Tardif lui répond.
A pyramid with its top cut off 2003-07-21
David pose la question :
What is the name given to a 3D shape that looks like a pyramid with its top cut off?
Penny Nom lui répond.
Slope 2003-07-20
Brian pose la question :

You are placing a pipe 60 feet long at a slope of 1.5%. How would you figure the amount of drop from the inlet of the pipe tot he outlet of the pipe? and what is the answer .

If you are trying to keep a shoulder slope of a road between 3/4'' per foot and 11/2'' per foot . If the shoulder is 10 feet wide, how would you figure how much lower should the outside of the shoulder be than the edge of pavement and what is the answer ?


Penny Nom lui répond.
|x+3| = -15x 2003-07-19
Nathan pose la question :
Without the use of trial and error, is there a way of solving for x where |x + 3| = -15x? I know that x = -0.1875, but how do I find whether x + 3 is positive or not if I did not have this information (In other words, how would I solve whether the x-value was -3 or less, or if it was more than -3)?
Claude Tardif and Penny Nom lui répond.
"cubic feet" of a refrigerator 2003-07-16
Ron pose la question :

Is the volume of a home appliance (e.g. fridge or freezer) calculated in a different way? I am planning to replace both my fridge and my freezer but I'm unable to determine what size replacement to get.

For example, one company descibes their fridge as being 32"(L) x 30"(W) x 66" (H). I converted those measurements to feet (2.67 x 2.5 x 5.5) and I calculate the fridge to be 36.7 cubic feet. However, the company says the fridge is 18 cf.


Chris Fisher lui répond.
Cathy's Clothing 2003-07-15
Cathy pose la question :
I am supposed to write a practical and useful word problem that would use the following algebriac inequality to solve it: 12x + 25 > 15x + 10. State the quanity that represents x and solve the inequality.
Penny Nom lui répond.
Preparing 100ml of a 30% alcohol solution 2003-07-13
Justin pose la question :
My question is how do you prepare a 100ml of a 30% alcohol solution using 95% alcohol?
Penny Nom lui répond.
Sunshine? 2003-07-11
lori pose la question :
It is noon, your lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on your radio you hear the weathercaster predict that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shining in 36 hours?
Claude Tardif lui répond.
A problem with lugs 2003-07-11
Lori pose la question :
A young man's car developed a flat tire as he was driving along a deserted street. He pulled over to the curb and did all the usual things: removed the hub cap, unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them fell down a nearby grate. Peering through the bars of the grate the man thought that he could see the lugs about 6 feet below in a shallow water puddle. He had a problem. How do you think he solved it?
Penny Nom lui répond.
A mixture problem 2003-07-10
A student pose la question :
Having a problem with word problems. example A chemist mixes a 10% acid solution with a 50% acid solution to form 400mL of a 40% solution. How much of each solution should be used.
Penny Nom lui répond.
A triangle in the complex plane 2003-07-10
Scott pose la question :
The vertices O and A of an EQUILATERAL triangle OAB in the complex plane are located at the origin and 3 + 3i. Find all possible values for the complex number representing the vertex B. Give the location of B in both polar and cartesian form (to 2.d.p)
Penny Nom lui répond.
E(X + Y) and V(X + Y) 2003-07-10
Reuben pose la question :

I'm a teacher trying to find a way to make some stats work from first principles. The topic is expectation algebra and it is for the top age level in high school.

By using a set of data I can show how the mean is the same as the expected value ie 2,2,3,4,4 is 15 / 5 = 3 also, 2x0.4+3x0.2+4x0.4=3. I can also show this to work for the variance in the same style but using Sum(x-mean)2/n and the Var(X) version of squaring x then multiplying by the probability ( all this for random independant samples).

Now comes the tricky bit.....when I try to show E(X+Y) = E(X) + E(Y) from setting up two data sets I get it to work only if I add each item from X to each item from Y. However, I can't get it to work for V(X+Y)=V(X) + V(Y) from two sets of data.

There must be something missing in my knowledge of how the sets are required to add together or my knowledge of expectation algebra. I am familiar with proofs but still want to show my students that the basic formulae work from groups of data whether done the long way or by use of formulae. Can you help please?


Penny Nom lui répond.
An onsale DVD player 2003-07-09
Kim pose la question :
I have a DVD player with a regular selling price of $175 and percentage of discount is 10 percent. How to solve for discount amount and sale price? Also, when you figure out the sale price how to figure out commission amount when percentage of commission is 5 percent?
Penny Nom lui répond.
A wooden deck around a pool 2003-07-09
Dat pose la question :
A pond is enclosed by a wooden deck that is 3 feet wide. The fence surrounding the deck is 100 feet long.
  1. If the pond is square, what are its dimensions?

  2. If the pond is rectangular and the length of the is three times its width, what are the dimensions of the pond?

  3. If the pond is circular, what is the diameter of the pond?

  4. Which pond has the most area?

Penny Nom lui répond.
Two cars 2003-07-09
Nicole pose la question :
Two cars start off at the same point on a striaght highway facing opposite directions. Each car drives 6 miles, talkes a left turn, and drives for 8 miles. How far apart are the two cars.
Penny Nom lui répond.
Is 3/5 CLOSEST to 0, 1/2 or 1? 2003-07-09
A student pose la question :
I would like to know is 3/5 CLOSEST to 0, 1/2 or 1. And can 3/10 go either way as to be closest to 0 or 1/2.
Penny Nom lui répond.
A geometry problem 2003-07-08
Chris pose la question :
My name is Chris, I work for a custom fabricator company. I am needing a formula for the Height (H) shown in the attached picture. The picture shows dimensions for my current application. If you could please, assign variables to the dimensions.
Harley Weston lui répond.
Volume of water in a pool 2003-07-06
An other pose la question :
How many litres of water are in a pool that is 16 feet in diameter and 35 inches deep?
Penny Nom lui répond.
The length of fabric in a roll 2003-07-03
Paul pose la question :
We receive rolled fabric as part of our process and I would like to know is there a formula that could be used to estimate the overall length of the roll with out rolling the fabric out and measuring its length.
Harley Weston lui répond.
Contradiction in the Procedural Precedence and the Distributive property 2003-07-03
Arthur pose la question :
When complicated expressions exist on both sides of a fraction, and both these expressions contain like and unlike terms with "literal" coefficients, the procedural precedence suddenly gets extremely confusing and seems impossible to simplify. This seems confusing and impossible to simplify because there is a HUGE contradiction in the way Procedural Precedence and the Distributive property deal with Parentheses. The Procedure says you MUST deal with what's INSIDE the parenthesis FIRST, BEFORE dealing with ANYTHING on the outside where as the Distributive property contradicts that by saying to go ahead and ignore the Precedence and use a factor on the outside of the Parenthesis.
Claude Tardif lui répond.
C is 10 more then the square of... 2003-07-03
Carolina pose la question :

C is 10 more then the square of the quotient of the sum of x and y , and the product of x and y. Which equation expresses this relationship?

A. C=(x+y +10)^2        ___        xy  
B. C=(x+y)^2 + 10        ___        xy  
C. C=(xy)^2+10           ___       x+y  
D. C=(x+y)^2 + 10        ___        xy 


Penny Nom lui répond.
The domain of 1/g(x) - 5 2003-07-03
Barbara pose la question :
If the range of g(x) is ( neg. infinity,4] and the domain of g(x) is ( neg. infinity, infinity), how do I find the domain of 1/g(x) - 5?
Penny Nom lui répond.
How much soil will be removed? 2003-07-02
Amy pose la question :
My site is 1230' (east-west) by 1300' (north-south) and we need to remove 2 feet of soil from the entire site, how much soil will be removed?
Penny Nom lui répond.
Setting up a word problem 2003-06-30
Christie pose la question :
A rectangular corral is forty feet longer than it is wide. If the perimeter is 220 feet, determine the length and width of the corral.
Penny Nom lui répond.
A ruler and compass construction 2003-06-29
Mandy pose la question :
I have been searching for instructions on how to do this using a compass. Can you please send instructions step by step on how to bisect a segment into any given number of segments. (example, a way that it will work for bisecting segment into 3, 4, or even 5 congruent parts)
Penny Nom lui répond.
Solve x = y^z for z 2003-06-28
Nathan pose la question :
If x = y^z is there a way to solve for z, if x and y are given, without guessing or already knowing the answer?

ie: 64 = 2^z
6 is the obvious value for z. Is there a way I could solve for this variable using a formula, which would also apply when more complex values were substituted for x and y?

Penny Nom lui répond.
Polynomials degree 4 and bigger 2003-06-26
Stephen pose la question :

How do I show kids how to find all the zeros for polynomials degree 4 and bigger.

For examples:
r(x) = x5-11x3-7x2+77 = (x2-11)(x3-7) and s(x) = x4-121 = (x2-11)(x2+11)

Also am I correct when I say that the following are irreducible?

f(x) = x2-11
g(x) = x3-7
h(x) = x4-5


Harley Weston lui répond.
Odd powers of sine and cosine 2003-06-25
Antonio pose la question :
Can you please tell me how to integrate a trig function involving sine and cosine? I know if the powers of both the sine and cosine are even and nonnegative, then I can make repeated use of the power-reducing formulas. But for the question I have on my hand, the powers of both sine and cosine are odd: ( sin3x + cos7x ) dx.
Harley Weston lui répond.
Sesame Street on Stage 2003-06-25
Christie pose la question :
Sesame Street on Stage has different ticket prices for adults and for children under 6. Beth and her two children, ages 3 and 4, paid $15 to gain entrance, while Jamie and John Jacobs and their 2-year old daughter got in for $19.50. What is the ticket price for adults?
Penny Nom lui répond.
4-3(m+1)=(-38) 2003-06-25
Jamie pose la question :

I have a problem, like most of your mailers, I do remember BEDMAS but maybe I'm missing the finer points!

It's been a while, he goes

4-3(m+1)=(-38)

Penny Nom lui répond.
Interest compounded daily 2003-06-24
Jeff pose la question :
What would be the amount of interest charged or accrued and how is it calculated on principal balance of $209.12 @ 6% interest rate compounded daily for 70 days?
Penny Nom lui répond.
pst and gst 2003-06-24
Robin pose la question :
I need to find an easy solution to remembering how to calculated the gst and pst once I have the total amount. ex: my total is $154.40, I have to find the gst and then the pst. I live in bc so the taxes are 7% for gst and 7.5% for pst.
Penny Nom lui répond.
Flim 2003-06-24
Dan pose la question :
I have a 4th grader and the word (Flims) came up in her summer text,
Penny Nom lui répond.
An inch and a millimeter 2003-06-21
Greg pose la question :
The conversion factor for inches to millimeters 25.4 It strikes me as very odd that it's not some infinite decimal. I could understand this if one system was derived from the other but as I understand it they were derived independently. Is the conversion 25.4 or 25.4000XXXXXXX? If it's just 25.4 then how did that happen?
Harley Weston lui répond.
Numbers John likes 2003-06-20
Steve pose la question :
John likes 400 but not 300; he likes 100 but not 99; he likes 2500 but not 2400.

Which does he like?
900
1000
1100
1200

Penny Nom lui répond.
The sum of two numbers is 5 and their difference is 2003-06-16
Akhil pose la question :
The sum of two numbers is 5 and their difference is 11. What is the product of the two numbers?
Penny Nom lui répond.
A 40% markup 2003-06-12
Nick pose la question :
I am attempting to determine the Retail price of an item that costs me 11.00. Our company wants to sell it at a markup of 40%. I calculated this two ways, first the way I thought it should be done. Second, the way the calculator does it (and my accountant).

  1. Cost + Cost*(percentmarkup/100)= retail price 11.00 + 11.00*.40 = retail price 11.00 + 4.40 = 15.40 retail price

  2. Using the calculators Mark Up key the answer is 18.33. Or 7.33 more than the cost or 67%.

I am confused by this Mark Up key and how it calculates. I used a cost of $10.00 and marked it up 50%. I thought it should equal $15.00 but the calculator says $20.00? This seems to be 100% markup, yes?

Can you explain the difference between the way I did it and the way a Business calculator does it?


Penny Nom lui répond.
A project about crosses 2003-06-10
Joel pose la question :

I have this project to do about crosses and I can't think of what the answer is for the following questions: What is the area rule of the crosses (the table below will help you)?
Cross NumberArea sq cm
15
213
325
441
561

I also need to know what the formula is for it?


Penny Nom lui répond.
Teaching second grade 2003-06-10
A teacher pose la question :
I am going to be teaching second grade next year. How can I differentiate instruction in mathematics to meet the needs of all of my students, from those who need intervention to those who need challenges? What are some techniques I can try for this grade level?
Diane Hanson lui répond.
Two trig problems 2003-06-10
Bett pose la question :

I have this ongoing trouble with trig and solving triangles with laws of cosines and sines!! For example if it asks to solve triangle FGH, given angle G=102.7 , side f=14.2, and h=18.6. Now do I use law of cosines because I don't have the measure of an angle and length of the opposite side??I don't know where to go from here,I am totally confused!!!

I also have a problem with this word problem I have been doing. It asks: An airplane flies 847.5 km at a bearing of 237.3 degrees. How far south and west fo its original position is it? Huh? Please help!


Penny Nom lui répond.
How many gallons are in 83 liters? 2003-06-09
Anita pose la question :
How many gallons are in 83 liters?
Penny Nom lui répond.
Definitions and descriptions 2003-06-08
Tammy pose la question :
MY DAUGHTERS TEACHER ASKED HER TO GIVE BOTH A DESCRIPTION AND A DEFINITION OF THE FOLLOWING ... CIRCLE, SQUARE, TRIANGLE,HEXAGON...... THE LIST GOES ON. WHAT IS THE DIFFERENCE BETWEEN DEFINITION AND DESCRIPTION ? DO A CIRCLE FOR AN EXAMPLE PLEASE.
Penny Nom lui répond.
The metric and Imperial systems 2003-06-08
Ashlee pose la question :
i am a year 8 student, and i am doing my Maths talent quest on the Metric and Imperial number system.

i was wondering, where did the 2 systems orginate and if possible, a little bit or information.

I also need to know the conversions of ounce, foot, mile..etc..from imperial to metric.

Penny Nom lui répond.
A radio controled car 2003-06-08
Robert pose la question :
I have a radio controled car (scale size 1/43). This car can travel 490 ft. per minute. I would like to know how fast that is at that scale size in miles per hour (and Kilometers per hour)?
Penny Nom lui répond.
Spacing the spindles for a railing 2003-06-06
Jennifer pose la question :

Scott is a homebuilder. He builds railings in which he places spindles. Spindles ar evertical posts taht are equally spaced beneath a horizontal bar. Scott would like a mathematical model to help him determine the amount of space to put between each spindle. The railing must follow the following criteria: The spaces between each spindle must be equal except for the ones at either end. Theses spaces are smaller. They are half the width of a spindle less than the other spaces. The number of spindles needs to be minimized since spindles are costly.

Help Scott determine what width of space to use between the spindles. Create a mathematical model to determine the width of space between each spindle in termso f the number of spindles. Use an 8' (96") railing that has 2 1/2" wide spindles. Explain your thinking. For safety reasons the maximum width of a space is 4"

Generalize you model to determine the width of spaces for total railing of length L and spindle width s


Penny Nom lui répond.
The square footage of a section of land 2003-06-04
Diane pose la question :
We are trying to calculate the square footage of a section of land with the following dimensions:

One end is 100 feet. The other end is 105 feet.. One side is 350 feet and the other side is 372 feet. I calculated the area as 35,875 sq. feet, however, the brochure for the land says the area is 36,200 + sq. feet.

Leeanne Boehm lui répond.
$22,534.56 is what percent of $27,820.00? 2003-06-04
Minnie pose la question :
$22,534.56 is what percent of $27,820.00?
Penny Nom lui répond.
BEDMAS 2003-05-31
Kristie pose la question :
(3x50)+20/5=?

I know bedmas but i forget how to do it.

Penny Nom lui répond.
$1/week for week 1 and then double each week 2003-05-28
A student pose la question :
I AM DOING A PROJECT FOR MATH I AM TRYING TO CREATE A SEQUENCE BASED ON: MAKING A SALARY OF $1/WK FOR THE FIRST WEEK WITH IT DOUBLING EVERY WEEK FOR 52 WEEKS, SO MY SEQUENCE LOOKS LIKE THIS: 1,2,4,8,16,32,64,128,256,512,1024 ETC. THERE WOULD BE 52#'s TOTAL IN MY SEQUENCE.I BELIEVE IT IS CALLED A FINITE SEQUENCE. MY QUESTION IS HOW DO I CREATE A FORMULA/RULE FOR THIS PARTICULAR SEQUENCE? MY GOAL BEING TO FIND THE 52nd TERM IN THE SEQUENCE.
Penny Nom lui répond.
5 to the power n 2003-05-28
Sam pose la question :
What is the integer n for which

5 to the n power + 5 to the n power + 5 to the n power + 5 to the n power + 5 to the n power = 5 to the 25th power?

Penny Nom lui répond.
Millimeters to inches 2003-05-28
Brian pose la question :
I am a music instructor just trying to get a horn repaired. I have been trying to get replacement pearls for a keyboard of a horn. The mechanic needs the measurement in inches. The calibers say that the size is .115 mm can you tell me what that is in inches, I tried your formula of 2.54 mm per inch but this is a smaller size and I cannot seem to figure it out.
Penny Nom lui répond.
George and his goat herd 2003-05-27
A student pose la question :

George the bulgarian goatherd drives his father's goats into a valley each morning and lets them browse there all day before driving them home in the evening.

he notices that each morning the goats immediately separate into groups and begin to feed the number and sizes of the initial groups vary some days there are nine and so days there are three or fewer. there can be groups of one or the whole group.

about every five minites one goat breaks away from each feeding group and these breakaway goats form into a new group.

George has noticed that by the afternoon, even though the goats continue their regrouping the sizes of the groups have stabilised, and there is always seven feeding groups.

How many goats are there in the herd? What are the sizes of the feeding groups once they have stabilised?


Penny Nom lui répond.
Two sequences that agree in the first 4 terms 2003-05-26
A student pose la question :
Is it possible to have two formulas that define sequences that agree on the first four terms but not the rest?
Penny Nom lui répond.
The cross-section of a football field 2003-05-25
Francis pose la question :
Have you ever walked on a football field covered with artificial turf? If so, you probably noticed that the field is not flat. The profile of the surface is arched and highest in the centre, permitting rainwater to drain away quickly.

height from base to highest point- 45.75 centimetres distance of the field- 50 metres

a) The diagram shows the profile of an actual field, viewed from the end of the field. Assuming that the cross-section is a parabola, find the algebraic model that describes this shape.

b) Use your equation to determine the distance from the sidelines where the field surface is 20 cm above the base line.


Harley Weston lui répond.
Two piles of cards 2003-05-24
Sam pose la question :
A standard deck of 52 cards (26 red, 26 black) is separated into two piles, not necessarily equal in size. The first pile contains seven times as many black cards as red cards. The second pile contains a number of red cards that is a multiple of the number of black cards in that pile. How many red cards are in the first pile?
Penny Nom lui répond.
An array of pennies 2003-05-23
Saundra pose la question :
If you have 100 pennies and you are suppose to make an array do you arrange the pennies by date?
Penny Nom lui répond.
The weight of a fish tank 2003-05-20
A ponderer pose la question :
I had a question pertaining conversion units..I have a fish tank at home and the dimensions are 24, 44, and 48 inches, I want to find out how much it weighs in pounds when filled up with water...knowing water is 62.4 pounds per cubic feet...do I just divide the 62.4 pounds to 12 because I"m trying to find out through cubic inches.
Penny Nom lui répond.
The HCF and LCM of polynomials 2003-05-20
Charanpal pose la question :

Question:
Find the HCF and LCM of the polynomials given below. Verify that he productof these HCF and LCM differs from the product of the polynomials, if at all, by a factor of -1

  1. 1-x2 and x3 -1
  2. 1 - x2 and x4 - 1

Penny Nom lui répond.
A trig identity 2003-05-20
Patty pose la question :
Please help with the following

1/ tanx + cotx = sinxcosx

Penny Nom lui répond.
R= 5.3lnx + x. 2003-05-11
A student pose la question :
Reaction R to a dose x is given by: R= 5.3lnx + x. For a certain drug, R must not exceed 21. Show that a dose between 8 and 12 units satisfies this requirement & find, correct to 5 decimal places, the greates value of x which satisfies this condition?
Harley Weston lui répond.
Subtracting rational expressions 2003-05-10
Simone pose la question :
hi, i'm totally lost. i understand that you need to find a lowest common denominator to subtract two fractions (rational expressions) with different denominators. but what if the denominators are "x-1" and "x". is x the common denominator? if so what happens to the "-1"? do you know of any live online help i can get with the following:

3/(x-1) - (1-2x)/x

i've looked through my notes and have no examples that quite match that i can follow to get through it. please help!
Penny Nom lui répond.

x-6square root of x +8=0 2003-05-10
Elizabeth pose la question :
x-6square root of x +8=0
Penny Nom lui répond.
Circumference 2003-05-09
A parent pose la question :
Find the circumference use 3 1/7 for pi

1. r= 28 ft.
2. D=98 cm

Penny Nom lui répond.
Real numbers 2003-05-09
Sirena pose la question :
what is a "real" number
Penny Nom lui répond.
sin theta = 7/8 2003-05-07
Patty pose la question :
If sin0 = 7/8 and 0 is in quadrant 2, find the other five trigonometric functions of 0. (report your answers in radical form)
Penny Nom lui répond.
ABCD*4 = DCBA 2003-05-07
Dee pose la question :

In the following problem, if the letters A, B, C and D represent some number, what numbers would they represent so that:

ABCD*4 = DCBA


Penny Nom lui répond.
2/sqrt(2) 2003-05-07
Mike pose la question :
I was looking at an example of csc 45 deg where

csc = hyp / opp = 1 / (sqrt(2) / 2) = 2 / sqrt(2) = sqrt(2)

I just don't get this. If sqrt(2) = 1.4142145..... How can 2 / sqrt(2) = sqrt(2) as the example shows?


Penny Nom lui répond.
Rules of exponents 2003-05-05
Carl pose la question :
Hi, I am a student who would like to recall how to multiply exponents. Here is such an equation:
6.02569 X 1025 X 5.254 =?

Also, adding exponents. Don't I just add subtract the exponents separately?
Such as 523 +15-12 =??

Penny Nom lui répond.
Write sin(3x) in terms of sin(x) 2003-05-05
A student pose la question :
Write sin 2x in terms of sin x
Penny Nom lui répond.
Four digit palindromes 2003-05-05
Heather pose la question :
How many palindromes were in between the numbers 1000 and 9999?
Penny Nom lui répond.
Integrating e^x sin(x) 2003-05-03
Lech pose la question :
I am having trouble integrating the following expression by parts:

ex sin(x)

I used the integrator at http://www.integrals.com/ to find the solution,

? 1/2 ex cos(x) + 1/2 ex sin(x).

This is easy to confirm by differentiation, however I am confounded as how to arrive at the answer.


Penny Nom and Claude Tardif lui répond.
The volume of air flowing in windpipes 2003-05-02
James pose la question :
The volume of air flowing in windpipes is given by V=kpR4, where k is a constant, p is the pressure difference at each end, R is the radius. The radius will decrease with increased pressure, according to the formula: Ro - R = cp, where Ro is the windpipe radius when p=0 & c is a positive constant. R is restricted such that:
0 < 0.5*Ro < R < Ro,
find the factor by which the radius of the windpipe contracts to give maximum flow?

Penny Nom lui répond.
positive multiples of 10 that are the sum of four consecutive integers 2003-05-01
Taurus pose la question :
How many positive multiples of 10 that are less than 1000 are the sum of four consecutive integers?
Penny Nom lui répond.
A circle, tangent to two circles and a line 2003-04-30
Keith pose la question :
I have a horizontal line (that is treated as a datum line or the X axis), with two circles having their center points at different heights from that line (X1,Y1 & X2,Y2). The two circles are also at different diameters (R1 & R2). Both circles and the line (X-Axis) do not intersect nor are they tangent. My goal is to determine the maximum diameter of an inscribed circle that will fit between all three.
Chris Fisher and Harley Weston lui répond.
A binomial probability 2003-04-30
Erica pose la question :
In a biathlon, athletes shot at 20 targets. A particular athlete had a probability of 0.18 of missing a target. Assuming a binomial distribution, what is the probability, to the nearest thousandth, that the athlete hit exactly 16 targets?
Andrei Volodin lui répond.
Some shapes 2003-04-29
Suzanne pose la question :
  1. What shape has 12 edges all the same length?

  2. What shape has 3 surfaces and 1 is curved?

Penny Nom lui répond.
Profit for a dance studio 2003-04-28
Craig pose la question :
A dance studio charges $80 per student for a series of 2 hour lessons. The studio's costs are $30 per hour for the instructor, $15 per lesson for the room rental, and $3 per student for miscellaneous expenses. If x is the number of students enrolled in the class, express the studio's profit P(x) in terms of x. Find the profit if 10 students are enrolled in the class.
Penny Nom lui répond.
A skill testing question 2003-04-27
Allan pose la question :
it is a contest Labatt Blue can you please give me the answer some people are saying 154 and some 34
Leeanne Boehm and Harley Weston lui répond.
20% of 40% of 500 2003-04-27
A student pose la question :
What is 20% of 40% of 500
Penny Nom lui répond.
The product of four consecutive integers is 3024. 2003-04-25
pillar pose la question :
The product of four consecutive integers is 3024. What are those numbers.
Penny Nom lui répond.
Gallons of rain 2003-04-25
Jocelyn pose la question :
If you have a surface of 6500 square feet and 1 inch of rain falls on the surface, how many gallons of water does this equal?
Penny Nom lui répond.
38 minus 10 plus 12 divided by 4 times 16 2003-04-23
James pose la question :
please help me work this math problem 38 minus 10 plus 12 divided by 4 times 16
Harley Weston lui répond.
Hidden by the curvature of the Earth 2003-04-23
Shirley pose la question :
There are 2 six foot men. What would the distance be between them before one could not be seen because of the curvature of the earth?
Penny Nom lui répond.
Two intersecting graphs 2003-04-23
Patty pose la question :

a) graph the equation

x2 - y - 4 = 0

x2 + y2 = 9
on the same set of coordinate axes.

I did not have a problem with this.

The problem is part (b) of the question ask: Find all solutions of the system in part (a) algebraically. Express answers in decimal form, accurate to two decimal places.


Penny Nom lui répond.
8 faces, 12 vertices, and 18 edges 2003-04-22
Thomas pose la question :
I would like to know the proper name for this geometrical solid. It has 8 faces, 12 vertices, and 18 edges?
Penny Nom lui répond.
One one 2003-04-22
Brad pose la question :
find the next two rows of numbers?
     1                        
    1 1                        
    2 1                      
  1 1 1 2                     
  3 1 1 2                    
1 1 1 2 1 3 

Leeanne Boehm lui répond.
The effectiveness of a drug 2003-04-22
A student pose la question :
A certain drug is found to be effective 80% of the time. Find the probability of successful treatment in two out of four cases.
Andrei Volodin lui répond.
Manipulating exponents 2003-04-21
Denita pose la question :
Rewrite using only positive exponents:

(4a^4b^2)^4 * (4a^ -3 bc^2)^ -3

Harley Weston lui répond.
Chopping trees 2003-04-19
Tamara pose la question :

The master needs some of the trees (twenty, to be exact) at the back of his spooky old mansion cleared to make way for a new evil laboratory, so he decides to send some his slaves to do the work for him.

He initially sends out four of his men, armed with axes, to chop the trees down. Due to the fact he is very impatient, every ten minutes he sends out another man to help with the work.

Assuming that it takes one man 30 minutes to chop down 1/3 of a tree, how long till all twenty trees are chopped down?


Penny Nom lui répond.
A tangent to a circle 2003-04-18
Lech pose la question :
The line with equation y=mx is a tangent to the circle with equation x2+y2-6x-6y+17=0. Find the possible values of m.
Harley Weston lui répond.
Interest compounded daily 2003-04-18
Bruce pose la question :
I recently received $7,987.68. This amount consisted of $7,543.61 invested at 6% per annum, compounded daily. I am trying to find out how many days this investment accrued interest.
Penny Nom lui répond.
The substitution method 2003-04-14
Patty pose la question :

I need help with the following:

5x - 4y = 13

2y + 3x = -1


Penny Nom lui répond.
The square of my age was the same as the year 2003-04-14
Pat pose la question :
Augustus de Morgan wrote in 1864, "At some point in my life, the square of my age was the same as the year." When was he born?
Penny Nom lui répond.
Area of a trapezoid 2003-04-13
A road builder pose la question :
My husband works with asphalt building roads. There are times when one end of the road will be (for example) 100ft wide the other end would be( for example) 200ft wide and he must figure the area in square feet. So far it has been a guessing game because he dosen't have the formula to figure the square feet.
Penny Nom lui répond.
Incremental standard deviation 2003-04-12
Carlos pose la question :
I need to calculate the standard deviation for a group of data, but I don't know in advance what is the mean. Is there a way to adjust the STDV for each datum without keeping all of the previous values? This is needed basicaly for performance, so I won't need to read twice the same data (spend processing time) nor save the previous values (spend memory).
Andrei Volodin and Penny Nom lui répond.
A fractional inequality 2003-04-08
Jessica pose la question :
Solve for x. Write in interval notation.

[(x2)-9]/[x-5] >= 0

Penny Nom lui répond.
The surface area of a cube 2003-04-07
Sarah pose la question :
if the volume of a cube is 64 cm, then what's the total surface area? I also want to know how to show my work.
Penny Nom lui répond.
Jo's books 2003-04-07
Miguel pose la question :
Jo announces, "I have more than 999 books."
Jean says: "No Jo! You have fewer than 1,000 books."
Mary says: "Jo has at least 1 book."
Only one of these statements is true. How many books does Jo own?

Penny Nom lui répond.
The area of a parallelogram 2003-04-06
A student pose la question :
Find the area of the parallelogram with vertices (0,0),(7,2),(10,7),(3,5)
Penny Nom lui répond.
The height of an equilateral triangle 2003-04-06
Rosa pose la question :
If Each side of an equilateral triangle is 10 m. What is the height?
Penny Nom lui répond.
How many hits? 2003-04-06
Jack pose la question :

My name is Jack. I'm a uncle. Student is in the 5th grade email is above.

If a baseball player at sping training had a good season with the following:

one seventh of his hits were doubles.
12.5% of his hits were home runs.
But didn't have any triples.
How many hits did he have?

Can you give me an explanation of you solved the problem.


Penny Nom lui répond.
Divide a circle in 8 equal pieces 2003-04-04
Naomi pose la question :
I have to divide a circle in 8 equal pieces but can only cut 3 times
can you please help me

Penny Nom lui répond.
Uses of conic sections 2003-04-01
William pose la question :
My name is William and I am doing a research paper on conic sections for my 12th grade math class. Part of the project is to find two conic sections in our world today and explain what there purpose is. I really need help in this area because I've been searching the internet for where conic sections are used in our world today and I really can't find anything. If you can tell me specific building or a pyramid that contains conic sections that would be great. Or even something in the universe would be helpful.
Leeanne Boehm lui répond.
Doubling the size of an object 2003-04-01
Dave pose la question :
If I have a known surface area and volume of an unknown object and I want to double the size of the object, how do I find the new area and volume?
Walter Whiteley lui répond.
A handshake problem 2003-03-31
Jaylan pose la question :
Suppose you and your partner attend a party with n other couples. Several handshakes took place. No one shook hands with himself (or herself) or with their partner, and no one shook hands with the same person more than once. After all the handshaking was completed, suppose you asked each person, including your partner, how many hands they had shaken. Each person gave a different answer.

Determine how many hands did you shake and how many hands did your partner shake when n=5

Penny Nom lui répond.
Quadratic word problems 2003-03-30
A student pose la question :
Question:
i think i know the basics of how to solve direct quadratic equations,but how do i go about solving those word problems? i have tried them times and again, but nothing seems to work at all!they are driving me crazy! pls help!:):):):):)

  1. bob & nick earned $1260 each. bob's hourly wage is $3 more than nick's hourly wage. he worked 2h less compared to nick. find the number of hours nick worked.
  2. there are 2 tanks in henry's house. in tank A, the fish are all goldfish. they are bought at a total cost of $259. in tank B, there are only guppies. the guppies were bought at a cost of $1.20 each. a day later,henry bought 3 more goldfish and put them into tank A. the number of guppies in tank B is now twice the number of goldfish in tank A.the total cost of all the fish that henry has presently,i.e. goldfish & guppies, is $355.30. given that the cost of each goldfish is the same,
    a)find the initial number of goldfish in tank A
    b)find the total cost of all the guppies.
  3. a particular disc can be made to rotate at 2 different speeds. if it is made to rotate slower by 135 revolutions per hour, it wld require an additional 2.7 hour to make 315 revolutions. find the higher speed at which it can operate.

Penny Nom lui répond.
12*nC2 = n! 2003-03-30
A tutor pose la question :
Solve for "N"

12*nC2=N!

Walter Whiteley lui répond.
The vertex of a cone 2003-03-27
Holly pose la question :
I read your response to Callie about whether a cone has a vertex or not. Is it ONLY a vertex if both halves of the cone are together or can one half of the illustration have a vertex?
Walter Whiteley lui répond.
Can twice a square be a square? 2003-03-25
Mike pose la question :
The other day it occurred to some students that they could think of no square number which is an integer, which can be divided into two equal square numbers which are intergers, Or put another way, no squared integer when doubled can equal another square integer. For example 5 squared plus 5 squared is 50, but 50 is not a square number.
Walter Whiteley and Claude Tardif lui répond.
A royal flush 2003-03-24
Vikki pose la question :

A poker hand consists of 5 cards selected randomly from an ordinary deck of cards: find the probability of a ROYAL FLUSH : the 10 , jack, queen,king and ace of the same suit.

I was thinking somewhere along the lines of:

*the number of ways to get the suit is 4C1
*the number of ways to get a 10 out of the 13 cards etc....
...but Im not sure I am going about this the right way, could you help?


Andrei Volodin lui répond.
Friends and enemies 2003-03-24
Becky pose la question :

Consider a room that contains six people. Any two people are either friends of each other, or they are enemies.

A. Argue why there are three people, all who are friends, or there are at least three people, all who are enemies

B. Rephrase the situation using graph terminology, using all of these terms correctly: vertex, edge, graph, complement, clique, independent set, and bipartite.


Penny Nom lui répond.
A triangle and a circle 2003-03-21
Jynks pose la question :
We need a formula that we can use to figure this out for work. We aren't math wiz's or students. Basically we know 3 points in space of a triangle, we know the length of each side and the length of the line from apex to base line. Each point of the base line ends upon the circumference of a circle. IS three a way to work out the radius of that circle.
Penny Nom lui répond.
Scientific notation 2003-03-20
A student pose la question :
what is one millionth times one thousand in scientific notation.
Penny Nom lui répond.
Gallons in a tank 2003-03-20
Leslie pose la question :
I am trying to figure the liquid gallons in a water tank that is 19" wide by 29.25" long and is 12.25" high. Could you tell me the formula to figure this out.
Penny Nom lui répond.
Harmonic numbers 2003-03-19
Becky pose la question :
Harmonic numbers are Hn = 1 + ? + 1/3 + . . . + 1/n

Use induction to prove the following theorem:
For all natural numbers n, H1 + H2 + . . . + Hn = (1+n)Hn - n

Penny Nom lui répond.
A recurrence relation 2003-03-19
Becky pose la question :
Solve this recurrence relation, with the initial conditions.

A1 = 10
A2 = 100
An = 10a n-1 + 29a n-2

Penny Nom lui répond.
The origin of integers 2003-03-19
Travis pose la question :
What are the real life usages of integers? Also what is the origin of integers?
Harley Weston lui répond.
1 followed by a million zeros 2003-03-19
David pose la question :
What do you call the number represented by the numeral '1' followed by one million zeros?
Penny Nom lui répond.
Two algebra problems 2003-03-18
Kayla pose la question :
1st question- If a+b divided by a equals 6 and b+c divided by c equals 9, compute the numerical value of a divided by c. ( Your answer will be mumbers only, no variables.)

2nd question- Three adjacent faces of a box (a rectangular prism) have areas of 7, 14, and 18 square inches. Find the volume of the box. (Hint: Choose variables to represent the three sides of the box and then figure out the problem.)

Peny Nom lui répond.
Three proffs of a trig identity 2003-03-18
Nadene pose la question :
Prove the identity. cos [x + (y-pi/2)] = sin (x+y)

A hint was also provided which is: "Apply cos (alpha + beta) first then within that apply cose (alpha-beta)"

Penny Nom lui répond.
An equilateral triangle 2003-03-17
Shirley pose la question :
An equilateral triangle is one in which all three sides are of equal length. If two vertices of an equilateral triangle are (0,4) and (0,0), find the third vertex. How many of these triangles are possible?
Penny Nom lui répond.
A sequence that converges to e 2003-03-16
Dane pose la question :
Something I noticed fooling around with a calculator about 30 years ago.
Considering e = 2.718281828459045....
Using Window's Calculator you will find


1.111 = 2.8531167...
1.01101 = 2.731861...
1.0011001 = 2.71964085...
1.000110001 = 2.71841774...
1.00001100001 = 2.7182954...
1.00000110000011 = 2.178231875...
1.000000110000001 = 2.178219643...


There apears to be a pattern. My conjecture is:


1.'infinite number of zeros'11'infinite number of zeros'1 = e.


Penny Nom lui répond.
Runs 2003-03-16
Diana pose la question :
How many arrangements are there with n 0's and m 1's, with k runs of 0's? (A run is a consecutive set [1 or more] of the same digit; eg. 000 111 0 11 00 has three runs.)
Penny Nom lui répond.
Distributing r identical balls into n distinct boxes 2003-03-16
Diana pose la question :
How many ways to distribute r identical balls into n distinct boxes with exactly m boxes empty?
Penny Nom lui répond.
Working backwards 2003-03-14
Melody pose la question :
Triva went to the ardcade at the state fair to win some goldfish. She already had some goldfish at home, but wanted more. She won enough goldfish to double her stock. Her mom made her give four away. She put her new ones in the tank with the others, by the morning half of the goldfish had died. Triva's friend gave her six more. The next morning two-thirds of her goldfish died. She was left with two goldfish after giving one to a friend. How many goldfish did she start with?
Penny Nom lui répond.
1575 2003-03-13
Sharyn pose la question :
find 6 integers that when multiplied with each other equal +1575 and when the same integers are added together equal zero. there are more positives than negatives and one of the numbers is a double digit between 10 and 20
Penny Nom lui répond.
An arc of a circle 2003-03-12
Melissa pose la question :
A strip of wood is 16 ft. long and is bent in the arc of a circle. Two radii, from the center of the circle to the ends of the arc, form a right angle. What is the approximate distance from one end of the wooden arc to the other?
Penny Nom lui répond.
Harmonic numbers 2003-03-12
Becky pose la question :
What can you tell me about the limit of harmonic numbers as it reaches infinity?
Penny Nom lui répond.
Monomials 2003-03-11
Roxy pose la question :
Explain why (x+y)z is not equal to xz+yz? P.S. Z is an exponent
Penny Nom lui répond.
Surface area of a sphere 2003-03-11
Kim pose la question :
a sphere has a surface area of 128 pi sq. units. What is its exact radius?
formula is 4 pi r2 I believe but how do I get radius

Penny Nom lui répond.
Division names 2003-03-10
A parent pose la question :
what is the answer to a division problem called
Penny Nom lui répond.
Three digit number 2003-03-10
Grace pose la question :
What three digit positive integer is exactly 32 times the sum of its digits?
Claude Tardif lui répond.
A question on combinations 2003-03-06
Jose pose la question :

I'm an architect student and have a question on combinations. I have a grid of 3 x 3, hence a total of 9 spaces. I have 3 elements to place in this grid.

How many possible ways are there of arranging this elements on this grid ? (order, orientation not important)

First putting the elements each in its own space and secondly allowing the elements at a given moment to "share" one space.

Since I got kind of obsessed with this I went ahead and graphically did all the combinations allowing "sharing", a grand total of 729. How could I have known this before hand ?


Penny Nom and Claude Tardif lui répond.
Mary typed a six digit number 2003-03-06
Pillar pose la question :
Mary typed a six digit number, but the two 1's did not show. What appeared instead was 2002. How many different six-digit numbers could she have typed?
Penny Nom lui répond.
(n+17)(n+7) = 0 2003-03-05
Janea pose la question :

What is the answer to 1. (n+17)(n+7)=0

What is the answer to:2. (y-15)(y-100)=0


Penny Nom lui répond.
Can a square be a rhombus? 2003-03-04
Beth pose la question :
Can a square be a rhombus? Some sources say yes, some say no. Some sources define a rhombus as a quadrilateral and parallelogram with equal sides, but without right angles. Some sources say a square is a special case of a rhombus. Clarity, please!
Walter Whiteley lui répond.
y < 2x + 1 2003-03-01
Erika pose la question :
how can I solve and graph y<2x+1 and which side in the graph should i shade after i finish solving my inequality?
Penny Nom lui répond.
Finding the area when the perimeter is known 2003-02-28
Yvette pose la question :
What is the size of an area in sqare feet when the perimeter totals 842 feet.
Sides are 190ft+180ft+200ft+54ft+118ft+100ft.

Penny Nom lui répond.
______cm=0.048km 2003-02-27
Antonette pose la question :
______cm=0.048km
Penny Nom lui répond.
Can a square be considered a rectangle? 2003-02-27
Carla pose la question :

Can a square be considered a rectangle? (since opposite sides are same length and parallel)

Would a regular hexagon or octagon be considered a parallelogram since its opposite sides are parallel? or does a parallelogram HAVE to have only 4 sides?


Penny Nom lui répond.
A number line 2003-02-27
Shery pose la question :

My seventh grader problem of the month

0__________1______________5____>

This is a arrow, the number should be below

A.Mrs Decker created an arrow representing a number line shown above. She wanted to find points and label them with a heart (G) for Valentine's Day so that the fraction 5/g is less than 1. (be sure to mark the G and not the fraction 5/g). She pondered, "Are there any other locations for G?" Is so help her description the location of all these points. If not why not?


Penny Nom lui répond.
A regular polygon 2003-02-26
Melissa pose la question :
The measure of each interior angle of a regular polygon is eight times that of an exterior angle of the polygon. How many sides does the polygon have?
Penny Nom lui répond.
X times Y equals ten million 2003-02-26
Baneen pose la question :
Would you be able to tell me which two numbers would compute ten million without any number having zeros in it?
Penny Nom lui répond.
(xy)z = 64 2003-02-26
Melissa pose la question :
How many ordered triples of positive intergers (xyz) satisfy (x[raised to the y])raised to the z = 64?
Penny Nom lui répond.
A section of land 2003-02-25
Bev pose la question :
How many acres in a section of land? How many square miles is in a secion of land?
Penny Nom lui répond.
The length of an arc 2003-02-24
Gavin pose la question :
does anyone have a formula for calculating the length of an arc if I have the circle radius and the cord length of the arc??
Penny Nom lui répond.
Excluded values 2003-02-22
Josh pose la question :
Why do you think it is necessary to include the "excluded values" when you write your answers to rational expressions?
Penny Nom lui répond.
A trig identity 2003-02-22
Ron pose la question :
We have spent hours trying to solve the following identity without success. Can you give us some hints as to how it is done?

1 + tan(x) tan(2x) = tan(2x) cot(x) -1

Penny Nom lui répond.
The number of possible outcomes with 8 games 2003-02-21
Gianni pose la question :
If 8 basketball games being played(no ties), which means a total of 16 teams, what are the total number of possible outcomes that can occur.
Penny Nom lui répond.
Percentage change in completion rate 2003-02-21
Remo pose la question :
In the year 2000 300 out of a possible 600 completed a phone survey for a total of 50% completion rate.

In the year 2001 20 out of 100 possible people completed the survey when it was re-done. This is a completion rate of 20%

To figure out the percentage change between the years can just use the difference between the percentage figures I already have? Or can I calculate it the same as you would for non-percentage numbers. For example you gave an example here of a salary increase from $20 to $95 being an increase of 375%.

Would I solve my problem the same way expect substituting my percentages (.5 and .2) in place of $20 and $95?


Penny Nom lui répond.
Deduct 60% from $150.00 2003-02-21
Mike pose la question :
How do you get this answer?
deduct 60% from $150.00

Penny Nom lui répond.
Percentage decrease 2003-02-20
Hope pose la question :
What number decreased by 331/3% is 30?
Penny Nom lui répond.
Density 2003-02-19
Rob pose la question :
What is the formula for converting cubic feet to pounds? (with any substance)
Penny Nom lui répond.
Hundreds, thousands, millions,... 2003-02-19
Karissa and Jasmeen pose la question :
hundreds, thousands, millions, - can you help us with the rest of this sequence - we are trying to find the largest number
Penny Nom lui répond.
Sasha's candies 2003-02-18
Pat pose la question :
Tick-tac-toe

Sasha and Trudy are playing tick-tac-toe. Sasha agrees to give trudy two pieces of candy for each game Sasha loses, and Trudy agrees to give Sasha three pieces of candy for each game that Trudy loses. After playing thirty games, Sasha has the amount of candy that he started with. If no ties occurred, how many games did Sasha win?

Paul Betts lui répond.
Order of operations 2003-02-16
A student pose la question :
How is the order of operation used in everyday life other than in a math class or at school? Also .... Can you give me a list of all the mathematician that are still living that uses the order of operation?
Claude Tardif lui répond.
Numbers in base 5 2003-02-16
Lori pose la question :
I'm trying to help my 6th grader with converting numbers like 82 to base 5 and 182 to base 12. We saw your examples on 613, but still are confused.
Penny Nom lui répond.
Order of operations 2003-02-15
Debbie pose la question :
Question: 20-(9+4)x7=?
Possible answer -71 or 49?

Penny Nom lui répond.
A determinant 2003-02-13
A student pose la question :

I have to find the determinant of the following matrix

-2 3 1 2 4
-3 0 -2 5 1
4 2 1 -3 5
2 3 4 -1 2
6 0 3 2 -4

Penny Nom lui répond.
Wrap a rope around the equator 2003-02-12
Ali pose la question :
If you take a rope and wrap it around the equator and then overlap it 6ft. and cut off the extra then you loosen it up so the ends meet how far would it stand off the ground?
Penny Nom lui répond.
Multiples of all four of the numbers 2, 3, 4, and 5 2003-02-11
Stephanie pose la question :
How many of the first 1000 positive integers are multiples of all four of the numbers 2, 3, 4, and 5?
Penny Nom lui répond.
Storyteller figurines 2003-02-10
A student pose la question :
It takes 3/4 of an hour to bake a storyteller figurine. If only one figurine can be baked at a time, how many can be baked in 6 hours?
Penny Nom lui répond.
Splitting weight 2003-02-10
Jin Ho pose la question :
A balance scale has only two weights, 1 ounce and 4 ounces. In only three weighings split 180 ounces of seed in two bags of 40 and 140 ounces.
Penny Nom lui répond.
Finite differences 2003-02-10
Jenny pose la question :

I need to find a formula that will work with any number.
I am finding the volume of a 3d cross- shape. Here are my results so far:

Term Number      0   1    2    3     4      5
nth term         1    7   25   63   129    231
1rst diff           6   18   38   66     102
2nd diff              12    20   28   36
3rd diff                  8     8    8

I can't seem to find a formula that will work with any number. Any help would be much appreciated.

Penny Nom lui répond.

Three consecutive positive intergers 2003-02-09
Yew pose la question :
Prove that when we multiply any consecutive positive intergers, the result is always divisible by 6.

ex. (7)(8)(9) = 504 = 6 (84)

Penny Nom lui répond.
AABBBCCCCAABBBCCCC... 2003-02-09
Patty pose la question :
The pattern AABBBCCCCAABBBCCCC continuously repeats. What is the 2003rd letter in the pattern? Please help, I am trying to figure out.
Penny Nom lui répond.
Millilitres and millimeters 2003-02-09
Iwan pose la question :
I was just wondering whether a millilitre was equal to a millimetre, if not, what is there difference.
Penny Nom lui répond.
BEDMAS 2003-02-09
Stefanie pose la question :
I do remember the rules of BEDMAS, but for some reason this question puzzles me.

6 X 9 - 3 + 44

I started with the Multiplication

54 - 3 + 44

But then I got stuck, do I proceed with adding the 44 and subtracting the 3
or figure out what -3 + 44 is, but then how would that work with 54?

Penny Nom lui répond.
Two investments 2003-02-07
A student pose la question :
you have $7200 in principal and invest different sums @ 10% and 14%. You receive 920 at end of term. (one year)What amounts are invested at what rate?
Penny Nom lui répond.
The area of an isoceles triangle 2003-02-07
A student pose la question :
I have to find the area of an isoceles triangle with one angle side of 30 degrees, and length of base 5. Could you please help me solve this problem?
Penny Nom lui répond.
A 15% markup 2003-02-07
Holly pose la question :
what is 15% markup of 58.89? please show equation and why? which is correct? 58.89 divided by .85 or 58.89 times 1.15
Penny Nom lui répond.
Two equations in two unknowns 2003-02-06
Patrick pose la question :
What are all ordered pairs of real numbers (x, y) for which: yx2 - 7x + 12 = 1 and x + y = 6?
Penny Nom lui répond.
Transformations of pattern blocks 2003-02-06
Cheryl pose la question :
I am trying to help my 8th grade son with Transformations - use of patttern blocks. He has to trace a figure and reflect it across the x-axis, which I can do, but then it indicates include ordered pairs - that confuses me.
Penny Nom lui répond.
Two airplanes leave Dallas 2003-02-06
A student pose la question :
TWO AIRPLANES LEAVE DALLAS AT THE SAME TIME AND FLY IN OPPOSITE DIRECTIONS. ONE AIRPLANE TRAVELS 80 MILES PER HOUR FASTER THAN THE OTHER. AFTER THREE HOURS, THEY ARE 2940 MILES APART. WHAT IS THE RATE OF EACH AIRPLANE?
Penny Nom lui répond.
The sum of the first 1000 even integers 2003-02-06
Jill pose la question :
What is the sum of the first 1000 even integers?
Paul Betts lui répond.
Milliliters 2003-02-04
James pose la question :
What is a milliliter?
Penny Nom lui répond.
Factoring 2003-02-04
Marcin pose la question :
I am having a really hard time with the factor theorem. Can you please help me with the following? (a'3 means a to the exponent 3)

a)8a'3+64b'3c'6
b)8x'4-12x'3-44x'2+24x
c)x'4-21x'2-100

Penny Nom lui répond.
Filling in the back yard with dirt 2003-02-04
Joe pose la question :

We just bought a house and need to start filling in the back yard with dirt to level it out.

I measure 37'x 56' by 2' deep on an angle.

I will be building a retaining wall at the 2' deep portion. The slop will go from the 2' to nothing at the top or near the house. I can't remember how to get the Sq. foot or cubic yards.


Penny Nom lui répond.
A train with 2 cars 2003-02-04
Michael pose la question :
A train with 2 cars is traveling at a speed of 80 km/hr from town X to town y, located 800 km from each other. At the same moment that the train departed, a passenger started to walk back and forth from one end of car B to the other at a speed of 100cm/sec. Arriving in town Y, the passenger had already gone and returned 720 times. The length of car A is that of car B plus one fourth of the length of the locomotive, and the length of the locomotive equals the length of Car A plus one fifth of the length of car B. What is the total length of the train?
Penny Nom lui répond.
Problem solving 2003-02-03
Brigitte pose la question :
My daughter is having lot's of problem with problem solving she is in grade 6. she is using mathematics in action from macmillan/ mcgraw- hill. Do you know of any way she can get help, and if there is any tests on line
Diane Hanson lui répond.
Arithmitic sequence 2003-02-01
A student pose la question :
I am having problems solving this arithmetic sequence... 1, 5, 10, ___, 50, 1.00, ___, 10.00, ... I believe the answers to be 25 and 5.00 but I can't figure why.
Claude Tardif lui répond.
Combinations of 1,2,3,4,5 and 6 2003-02-01
Kyle pose la question :
Today I was aked a question by my geometry teacher. It was, what is the sum of all the possible combinations of the numbers 1, 2, 3, 4, 5, and 6. He said all the possible combinations were 720. I would like to know how u could do this, and what the answer is.
Penny Nom lui répond.
1+2+3+...+500 2003-01-31
Brian pose la question :
What is the sum of the numbers from 1 to 500 inclusive?
Paul Betts lui répond.
Triangle perimeter 2003-01-30
An Aunt pose la question :

Hi I'm the aunt of a middle school child. He need help with two problems and I don't understand how to show he how to do them. Can you help me.

  1. How do you find the perimeter for X=4, X=0.7, and X=5/6?

  2. And an acute triangle that bottom is (3X+1) cm, left side is (X+4) cm and the right is (2X+5)cm.

Can you show me not only the answer but also the steps that you used.


Penny Nom lui répond.
I have three circles... 2003-01-30
Tony pose la question :
I HAVE THREE CIRCLE THAT IS CIRCLE TOGETHER: IN CIRCLE A, THE NUMBERS ARE: 11 I KNOW IS IN CIRCLE A, BUT I HAVE THE: 5 THAT IN A AND C, I HAVE THE 2 IN THE CIRCLE C AND B AND AND A, THE CIRCLE C I KNOW THAT 10 IS IN THE CIRCLE THE 4 IN CIRCLE A: AND B: IN CIRCLE B, I KNOW NUMBER 13 IS IN CIRCLE B; BUT I HAVE THE 3 IN CIRCLE B AND C AND I HAVE THE 2 IN CIRCLE B AND C AND A ,THE 4 IN CIRCLE B AND A.
HOW DO I FIND THE SUM IN CIRCLE C AND IN B IN BOTH CIRCLE A AND B AND B AND C NOT IN CIRCLE B, AND NOT CIRCLE C.

Penny Nom lui répond.
Fibonacci exam 2003-01-28
Mike pose la question :

My son will be participating in the national math contest. He is a grade 4 student but will be writing the Fibonacci exam for grade 5. He has been given last years exam for practice. Parents have been ask to assist for this part. I was therfore hoping for a little "inside" help on several questions with answers & short explanations. This with a would be greatly appreciated.(from last years exam)

  1. With 3 weights, Mathusalem can weigh any object that has a weight which is smaller or equal to 13 kg, but that weighs a whole number of kilograms. He wants to weigh an object of 7 kilograms. To do so, he must place two of the weights on the left side of the scale, and the third one on the right side. Which one will he have to place on the right side

    a)4 b)3 c)6 d)2 e)5
  2. Mathilda uses a rectangular prisms to build stairs. The cross section of each prism is a square which has a side of 1 dm. Mathilda has already put in place 4 steps of a staircase that must have a height of 10 dm. When finished, the staircase will have a volume of 550 dm3. What will the width of the staicase in dm be?

    a)10 b)55 c)11 d)1 e)100
  3. The year 1991 was the last palindrome year of the second millennium. The year 2002 is the first palindrome year of the third millennium. Including 2002, how many palindrome years will there be, altogether, in the third millennium ?
    a)8 b)2 c)10 d)182 e) 9


Greatly appreciated,
Mike


Penny Nom lui répond.
Factoring a trinomial 2003-01-26
A student pose la question :
how do you factor: Xsquared + 8x + 12
Penny Nom lui répond.
Extraneous solutions 2003-01-24
Paul pose la question :

What is an extraneous solution and in what cases do you get one?

How do you know it is extraneous?


Penny Nom lui répond.
Some 5th grade problems 2003-01-24
Sabrina pose la question :

[What is the greatest common factor of 20,28, and 36?] next problem is

[5k+7(k+8)= ] next problem

[Curtis simplified 0.8 divided by 0.2 x 0.04 and got 10. Latoya Simplified and got 1.6. is either correct? Can you explaine how you got the answer please.]


Penny Nom lui répond.
Dorothy and the wizard 2003-01-24
Ken pose la question :

dorothy was going to see the wizard of oz...she stopped at the bakery and bought a box of cookies.

she met the scarecrow and gave him half the cookies. she ate half of the remaining cookies and threw one half cookie away.

she met the tin man and gave him half the cookies. she ate half the remaining cookies and threw one half cookie away.

she met the lion. she gave him half of her cookies. she ate half the remaining cookies and threw the LAST half cookie away.

how many cookies did dorothy leave the bakery with?


Penny Nom lui répond.
6 digit numbers from 0,0,2,2,4,4 2003-01-23
Amanda pose la question :
How many 6 digit numbers can you make from the numbers 0,0,2,2,4,4, giving that 0 cannot come first. The number has to contain 2 twos, 2 fours, and 2 zeros.
Penny Nom and Claude Tardif lui répond.
The cousin of Sally's sister's boyfriend 2003-01-23
Michael pose la question :
Sally went to a farm to buy eggs. Returning home, she gave half of them to her sister who, in turn, gave a third of those she had gotten to her boyfriend. The latter, after eating one third of the eggs that he had gotten, gave the rest to his cousin. Given that each egg weighs 70 grams, that Sally cannot carry more than 2.5kg, and that the eggs were raw, calculate how many eggs the cousin of Sally's sister's boyfriend received.
Penny Nom lui répond.
The area of a regular n-gon 2003-01-22
Sophie pose la question :

We have been given a piece of maths coursework. A farmer has exactly 1000 metres of fencing and wants to fence off a plot of level land. she does not mind what the shape is but it must have a perimeter of 1000m. She wants to fence off the plot of land which contains the maximum area. Investigate the shape, or shapes that could be used to fence in the maximum area using exactly 1000 metres of fencing each time.

I have investigated many shapes, and I feel that a circle will have the biggest area. However we have also been asked to investigate shapes with 20 and 30 sides. My dad said that there is a formula for finding out any area of land. Do you know of this formula, if so I would be very grateful if you were to email it to me.


Penny Nom lui répond.
Rational expressions 2003-01-22
A student pose la question :

// = the main fraction line

1.) a+1/a-1 + a-1/a+1 // a+1/a-1 - a-1/a+1

2.) 2/a(squared)-3a+2 + 2/a(squared)-a-2 // 2/a(squared)-1 + 2/ a(squared)+4a+3


Penny Nom lui répond.
The least common denominator 2003-01-21
Brittan pose la question :
Hi there I need help! My name is Brittany and i am in the 6th grade.

I need help finding the least common denominator(LCD), and the book says Find the LCM of the denominators and i've done that and then it says write equivalent fractions,using the LCM as the least commonn denominator.The directions say Use the LCD to write each pair as like fractions. and the problem is 1/8 and 5/40. Could u explain how in the word u do this? Thanks a lot

Brittany

Penny Nom lui répond.
A penny, a nickel, a dime, a quarter, and a loonie 2003-01-21
Blaine pose la question :
I have 5 coins: a penny, a nickel, a dime, a quarter, and a loonie. How many different amounts of money could I pay using any combination of these coins?
Penny Nom lui répond.
Jo's books 2003-01-21
debra pose la question :
Jo announces: I have no more than 999 books.
Jean says: No Jo, You have fewer than 1,000 books.
Mary says: Jo has at least 1 book.

Only one of these statements is true, How many books does Jo own?

I do not know HOW to approach this problem and solve it.

Penny Nom lui répond.
Why quadratic? 2003-01-21
Dan pose la question :
Why are equations of the form aX2 + bX + c =0 call quadratic? The quad indicates 4 but the power is 2.
Penny Nom lui répond.
Cutting a board 2003-01-20
George pose la question :
A person has a sheet of board which he saws into two (2) pieces. The length of the first piece is two thirds the length of the original board, while the length of the second piece is four feet longer than the first piece. How long was the original board? (the length is defined as the longer of the two sides of the board)
Penny Nom lui répond.
Division by zero 2003-01-19
David pose la question :
I've been to your site and am interested on the subject of division by 0. It's easy enough to give answers, but it's very hard, especially in this case, to make someone understand a mathematical problem.

It's been about a year since my Calc class, and we never went over division by 0, only infinite numbers and such. My question is: How would you work a problem of (real number) / 0 ? As ignorant as it may sound to you, I am having trouble grasping this since I've only begun to understand some of it. Perhaps you could help.


Harley Weston lui répond.
25% more 2003-01-16
Charlie pose la question :
If I buy something for $10 and want to sell for 25% more, do I multiply by 1.25 or divide by .75? Or another way - why do I get $13.33 when dividing by .75 ?
Penny Nom lui répond.
Radians 2003-01-16
Erikson pose la question :
I am a student in the 10th grade and attending advanced math at my high school. I was assign to do a report about the unit circle and the radian. But there seems to be no information available about the history of the radian; who first found out about them, which civilizations used it if any. Well, hopefully you'll assist me in this troubling question. Thank you for your kind consideration.
Penny Nom lui répond.
0.027 acres 2003-01-16
Cory Lee pose la question :
How many square feet are in How many square feet are in .027 acres??
Penny Nom lui répond.
NO RED-HATTED DWARVES ALLOWED 2003-01-14
Dulce pose la question :

There are 1000 dwarves in Dwarfland. Now as you know, dwarves are born with either red or white hats on.

The dwarves in Dwarfland love to party. Every night, they all flock to the same club to dance the night away.

One day, a sign is posted at the club: "NO RED-HATTED DWARVES ALLOWED". A certain number of days pass, after which all of the white-hatted dwarves are in attendance,and none of the reds.

How did the red hats know not to come?

Assumptions:

  1. The number of red and white-hatted dwarves need not be equal. There are at least 1 of each color.

  2. There are no reflections or mirrors in Dwarfland (i.e. the dwarves can't see the color of their own hat), and no dwarf can reveal through direct or indirect means the color of another dwarf's hat.

  3. There is NO COMMUNICATION among dwarves

  4. No white-hatted dwarf ever misses a night of partying


Claude Tardif lui répond.
Collinear Points 2003-01-13
Gary pose la question :

Which of the 4 points are collinear when you construct the following concurrent lines or rays of a triangle?

  1. P(1), the point where the angle bisectors intersect.
  2. P(2), the point where the altitudes (or extensions) intersect (inside or outside of the triangle).
  3. P(3), the point where the medians intersect.
  4. P(4), the point where the perpendicular bisectors (or extensions) of the three sides of a triangle intersect.


This is for my 9-12 high school class in geometry.
My name is Gary


Thanks for your help.
Gary


Harley Weston and Chris Fisher lui répond.
Would it be worth paying $20K for 4 chances... 2003-01-13
Steve pose la question :

If I've got 4 chances to to achieve X goal, and in each chance that I have I've got a 65% chance of achieving this goal, what is my overall probablity of achieving this goal? Also, what would it be after each of my 4 chances (i.e., for my 2nd chance, would it be (.65 * (.65*.65)? I've forgotten some basic probablity theories, and would appreciate any help on this.

With the probablities above, would it be worth paying $20K for 4 chances to achieve the goal or $8.5K for only 1 chance to acheive the goal? (at 65% probability)


Andrei Volodin lui répond.
5x(-2)-32/8 2003-01-13
A student pose la question :
I'm having problems solving this question:
5x(-2)-32/8

Penny Nom lui répond.
What is larger than infinity? 2003-01-12
Dana pose la question :
What is larger than infinity?
Claude Tardif and Harley Weston lui répond.
Cubic yards in a gravel pile 2003-01-10
Ron pose la question :
I am looking to find a way to measure gravel piles to get yards. They are generaly not square.it would be like pouring sand out of a bag into a pile. they generaly are concave in dimension. can you help. I have attached a picture to show a small scale what I am working on is in much larger volume.
Harley Weston lui répond.
A rectangular prism 2003-01-09
Julie pose la question :
How many faces on a rectangular prism and how many bases? Can the base also be a face and can a face also be a base?
Diane Hanson lui répond.
Intercepts 2003-01-08
Nay pose la question :
my name is nay 8th grade student how do i figure out an intercep and does it always have to have (0, ) or ( ,0)?
Penny Nom lui répond.
Repeating decimals 2003-01-08
A student pose la question :
If k=.9repeating, and 10k=9.9repeating then 10k-k=9k, k=1 therefore .9repeating=1 and 1/3=.3repeating 3x1/3=.3repeatingx3, 3/3=.9repeating, therefore 1=.9repeating

It would seem to me that .9repeating approaches one but never quite makes it. Can you clarify?


Penny Nom lui répond.
The area of my lot 2003-01-07
Linda pose la question :
I have a lot that is 210 feet in the front, 240 feet in the back and the sides each measure 150 feet. How many square feet is this all together and how close to an acre is it?
Penny Nom lui répond.
Integration of 1/(2+cos(x)) 2003-01-07
A student pose la question :
integral from pi to 0 of

dx/(2+cos x)

i used the substitution t=tan(x/2) and i ended up with

integral from +infinity to 0 of

2dt/(t2+3)

which looks like an inverse tan function , and i ended up with sqr(27)/2 pi , which is not the same as my calculator's answer , so i suspct i am doing some thing wrong. can some one tell me where i am going wrong please.
Penny Nom lui répond.

Mean and median 2003-01-04
Jan pose la question :

I have a question re: mean and median. I know what the difference is but just need some clarification on when you would use the mean and when you would use the median. Isn't it the case that with a skewed distribution the average (mean) would be higher or lower than the median, but with a normal distribution they would be very similar values?

If you have any examples to help explain this that would be greatly appreciated.

I am a teacher (of sorts!) and the person who is asking me the question is actually my boss!


Penny Nom lui répond.
Constructions of polygons 2003-01-03
Garrett pose la question :
Our teacher just finished the constructions unit, and he mentioned briefly about odd sided figures such as pentagons and septagons, only that they're very hard. My question is, how do you draw, with a compass and a straight edge, a pentagon and septagon?
Chris Fisher lui répond.
Two numbers have a ratio of 5:3 2003-01-01
Patricia pose la question :
Two numbers have a ratio of 5:3. The larger number is 36 more than half the difference of the two numbers. What are the two numbers?
Penny Nom lui répond.
Augmented matrix 2002-12-31
Michelle pose la question :
I am trying to augment a matrix so that i can find the values of the variables a, b, and c. For the life of me i can't find a solution to the matrix: 3 -5 2 ' 22 2 3 -1 ' -9 4 3 3 ' 1 I thank you for your help, Michelle
Penny Nom lui répond.
Successive coefficients in Pascal's Triangle 2002-12-27
Quincy pose la question :
There is a formula connecting any (k+1) successive coefficients in the nth row of the Pascal Triangle with a coefficient in the (n+k)th row. Find this formula
Penny Nom and Walter Whiteley lui répond.
Averages of Averages 2002-12-21
Amy pose la question :
If in the month of October the % of Payments Received was 80.74% and in November it decreased to 69.36%. Can you take the 80.74-69.36/69.36 to get the % of difference. In otherwords can you take the % of difference when the numbers you are comparing are %'s????

Can you also take an average of an average? For example, average number of payments received in October was 25.00%, average number of payments received November was 50.00%, and the average number of payments received in December was 15.00%. Do you average (25.00%, 50.00% and 15.00%) or do you have to go back to the numbers that calculated the averages. For example, October 25.00% was based on 25 payments being received out of a possible 100. So instead of taking the average of the averages, do you take the average payments and the average customers over the 3 months and calculate the average???


Harley Weston lui répond.
20% of 40% of 500 2002-12-19
Richard pose la question :
What is 20% of 40% of 500?
Penny Nom lui répond.
The intersection of conics 2002-12-19
Glenda pose la question :
We are studying systems of equations where two conic sections are the two equations that we are solving simultaneously. We were studying the number of solutions that are possible if you have an ellipse and a parabola. We all agree that there can be none, one, two, three or four solutions. The question that the students had for me was whether or not a portion of an ellipse and a parabola can overlap and thereby allow an infinite number of solutions. What should I tell them?
Chris Fisher and Harley Weston lui répond.
The units digit of 2 to the power of 31921 2002-12-18
A student pose la question :
If 2 to the power of 31921 is multiplied out, what will be the units digit?
Penny Nom lui répond.
Odd and even 2002-12-17
Martin pose la question :
I am a graduate engineer trying to teach single digit addition to my 8 year old grand-daughter. My questions follow.

Assume a child does not know what multiplication and division are.

Assume the child knows how to count from 0 to 10

How do you explain that 2, 4, 6, 8 and 10 are even numbers

And 1, 3, 5, 7 and 9 are odd numbers

And these three facts?

  1. when you add two even numbers, the answer is even
  2. when you add two odd numbers, the answer is even
  3. when you add an even number and an odd number, the answer is odd?

Can all of these be reasoned out, without using the concepts of multiplication or division?


Diane Hanson lui répond.
Calculations 2002-12-15
Mahdi pose la question :
This problem is rather general, but it usually makes a lot of problems. I almost have no difficulty in math and physics questions, but unfortunately I'm not at all accurate in simple one or two digit calculation. I even sometimes make silly mistakes in simple sums like 7+4=12 or 4+5=11! Is there any effective way to reduce these mistakes?
Walter Whiteley lui répond.
A bouncing ball 2002-12-14
Eman pose la question :

Q : When a childís ball is dropped from a height h metres on to a hard, flat floor, it rebounds to a height of 3/5h metres. The ball is dropped initially from a height of 1.2m.

  1. Find the maximum height to which the ball rises after two bounces.
  2. Find the total distance that the ball has traveled when it hits the floor for the tenth time.
  3. Assuming that the ball continues to bounce in the same way indefinitely, find the total distance that the ball travels.

Penny Nom lui répond.
Two modes 2002-12-12
ali pose la question :
I have a math assignment to pick the mode in a set of data. 12 and 21 both appear twice in the data set. What is the mode?
Penny Nom lui répond.
Units 2002-12-12
Debbie pose la question :
The general equation for a parabola is y = ax 2 + bx + c, where a, b, c are constants. What are the units of each constant if y and x are in meters?
Penny Nom lui répond.
Construct a pentagon 2002-12-12
Mary pose la question :
We were wondering what the instructions/formula, step-by-step, is to make a pentagon.
Chris Fisher and Penny Nom lui répond.
A sphere with a hole - cylindrical shells 2002-12-11
Kathy pose la question :
Suppose you make napkin rings by drilling holes with different diameters through two wooden balls (which also have different diameters.) You discover that both napkin rings have the same height, h.
  1. Guess which ring has more wood in it and why.
  2. Check you guess: Use cylindrical shells to compute the volume of a napkin ring created by drilling a hole with radius r through the center of a sphere of radius R and express the answer in terms of h.

Penny Nom lui répond.
Factoring 2002-12-11
Larry pose la question :
Question:

how do u factor trinonmials

EX: X 3 + Y 3

X 3 - 8Y 3

8X 2 - 72

64A 3 - 125B 6

Penny Nom lui répond.
Find a, b and c 2002-12-10
Sameer pose la question :
Question:

a+b+c=180
b=a+(120/2-5)
c=b-(130-10)/6
a=?
b=?
c=?

Penny Nom lui répond.
Fractions 2002-12-10
Jean pose la question :
What are some activities to use with advanced students in grade 7 to apply their knowledge of fractions and decimals. I'm looking for a project type of activity.
Diane Hanson lui répond.
Quadratic equations 2002-12-10
Katie pose la question :
just bugging the hell outta me and I cannot figure it out for the life of me.

1)x-2x-1 =0
Find both roots. You must simplify both of your roots. This equation requires the use of the Quadratic Formula. I have tried everything for this and I am still either getting the wrong answers, and end up getting really frustrated. If you could find the answers and tell me how you did it I would greatly appreciate it! Then the second problem is

2) The square of a certain negative number is equal to 70 decreased by 3 times the number. Find the answer! On this one I set it up but still came out with the wrong answer. So if you could help me on this one I would greatly appreciate it!

Penny Nom lui répond.
y = 1 - sin(x + 60) 2002-12-10
Eman pose la question :
Sketch the graph of y = 1 - sin(x+60). for 0 <= x<= 360, giving the coordinates of the maximum and minimum points and the pints where the curves crosses the y axis.
Penny Nom lui répond.
ALL of the possible 3 digit combinations of 0 - 9 2002-12-09
Melissa pose la question :
I need to find out ALL of the possible 3 digit combinations of 0 - 9. Eg: 000,001,002,003. This is going to take me VERY LONG time. Any suggestions.
Penny Nom lui répond.
How many billions equal one trillion? 2002-12-07
Ryan and Aylah pose la question :
How many billions equal one trillion?
We believe that the answer is one thousand times one billion equals one trillion. Please help us with the answer to this question.

Penny Nom lui répond.
A function that is onto but not one-to-one where f:N-->N 2002-12-06
Lisa pose la question :
A function that is onto but not one-to-one where f:N-->N
Penny Nom lui répond.
Integer arithmetic 2002-12-05
A student pose la question :
Would you please help me with a question?

I am just learning about integers. Can you show me in a way I might understand....My teacher can tell me what is required to do the math, but it just doesn't make sence to me.

(+4) - (-3) =+7

Why is the answer not +1

Diane Hanson lui répond.
A rope trick 2002-12-05
Jerry pose la question :
My name is Jerry and I am a math teacher at the secondary school level in the greater Toronto area. I posed the following problem to my enriched grade 10 math class that I found in the book called "Mathematics and the Imagination" by William Kastner. According to the author, it is posible for two people linked to each other with two ropes around their hands, to separate themselves without letting go of the rope. The students had lots of fun trying to accomplish this problem using skipping ropes from the Phys Ed department, but with no success.
Penny Nom lui répond.
Factoring a cubic 2002-12-05
Dorota pose la question :
I got a problem with factorise the expression
2x3+11x2-5x-50.

Penny Nom lui répond.
Which is the better buy? 2002-12-04
Lynda pose la question :
my question is the big can held 18 ouces and cost $2.52.The small can held only 12 ounces and cost $1.08. Find both unit prices. which can was better buy?
Penny Nom lui répond.
65,125 2002-12-04
Brittany pose la question :
I am a three-digit number.When you reverse my digits,a larger number is formed.the product of me and the new number is 65,125.What number am I.
Chris Fisher and Claude Tardif lui répond.
The dimensions of a box 2002-12-03
Paula pose la question :
My son, who is in secondary school, needs to make a box with the inside dimensions of 1.25 cubic feet. It's supposed to be more in the shape of a rectangle than a square.

I would like to know the equation to use to find the inside dimensions of a box if I know how many cubic feet (or inches) I need the inside to be.


Penny Nom lui répond.
A Normal probability problem 2002-12-03
A student pose la question :
The height of married men is approximately normal with mean 70 and standard deviation 3. The height of married women is approximately normal with mean 65 and standard deviation 2.5. What is the probability that a random married woman is taller than a random married man?
Andrei Volodin lui répond.
A geometric sequence 2002-12-02
Wanda pose la question :
the fifth term of a geometric sequence is 5/16. the common ratio is 1/2. What are the first four terms of the sequence.
Penny Nom lui répond.
Tiffany plays first board for her middle school chess team 2002-12-02
Patty pose la question :
Tiffany plays first board for her middle school chess team. Since she joined the team last year, she has won 27 of 51 tournament games. That's a winning percentage of about 53%.

If Tiffany went on a winning streak, how many games would she need to win in a row to raise her winning percentage to 60% Use variables and equations to communicate the method you've used to solve the problem.


Penny Nom lui répond.
How do you estimate the equation of a parabola? 2002-12-01
Audrey pose la question :
How do you estimate the equation of a parabola? I have a project where a must find parabolas in magazines and then estimate their equation.
Penny Nom lui répond.
Trigonometry 2002-12-01
Lance pose la question :
My question is:

FIND ALL SOLUTIONS cosx=1-sin(x/2) if x[0,2pi)

ALSO:

Given cscx=-5/4 and cot>0, find csc(x/2) and cot(x/2)

Penny Nom lui répond.
Trigonometry problems 2002-12-01
Chiara pose la question :
  1. Find tan 35pi/4
  2. Graph y = cos2x - 2sinx

Penny Nom lui répond.
The height of a triangle 2002-11-29
Dean pose la question :
Could you please tell me the formular for me to calculate the height of a triangle. I have the angles and side lengths. I am trying to calculate the height of an isosceles triangle, does this make a difference from a normal triangle or is the formular the same.
Penny Nom lui répond.
Constructing a tangent to two circles 2002-11-28
Tom pose la question :
I have two circles, different sizes a known distance from each other. We know the radii of the circles. How do I construct a line that is tangent to both circles relative to the segment that connects the centers of both circles?
Chris Fisher and Penny Nom lui répond.
x + y=80 and x + z=100 2002-11-28
PJ pose la question :
x + y=80
x + z=100

can you solve for x, y or z?


Penny Nom lui répond.
Miles per hour 2002-11-28
Liz pose la question :
If a car has traveled 16 miles in 30 minutes, how many miles per hour did they go?
Penny Nom lui répond.
The length of an arc 2002-11-27
Nancy pose la question :
If all I have is the length between 2 ends of an arc (72"), how do I find the length of the arc at its apex and the radius?
Penny Nom lui répond.
Combinations of 1,2,3,...,10 2002-11-27
Gord pose la question :
If I had the numbers from 1-10 how many different combinations would i have.....would it be 100....since that is 10 squared.
Penny Nom lui répond.
[x*(x+2)] + 1 = (x+1)(x+1) 2002-11-27
Melissa pose la question :
While teaching the multiplication table to my daughter I noticed an interesting pattern. It goes something like ...Take a whole number
...add two to it
...multiply the two numbers together
...add one to the resulting number
...it will now be equal to the original number plus one, squared.

Claude Tardif lui répond.
Making 7 2002-11-26
Bill pose la question :
At one time I had the answer to this math equation but I have lost it and can't seem to regain it. I may be going at it wrong but as I recall there were the numbers 1 through 4, and the std operators, +, -, /, *, and parentheses. The object was to make the four numbers with the operators equal to 7. Each number and operator may be used only once. My 9 year old loves these quizzes but I can't give it to her if I can't provide the correct answer.
Claude Tardif lui répond.
A two stage rocket 2002-11-26
Hoda pose la question :
a two stage rocket accelerates in free space by ejecting fuel at a constant relative speed , v(ex). the full fuel load makes up 80% of the initial mass of the entire two stage rocket . the rocket accelerates from rest until at the end of the first stage when 75% of its fuel has been burnt. find an expression for the speed of the rocket at the end of the first stage in terms of v(ex).
Claude Tardif lui répond.
A lampshade from a cone 2002-11-26
Ellsie pose la question :
I need to make a pattern to cover an old lampshade. This is actually the bottom portion of a cone. Please help me figure out how to draw this pattern, so that we can complete our project.
Penny Nom lui répond.
Decimals in everyday life 2002-11-24
Fritz pose la question :
How do you use decimals in your every day life?
Penny Nom lui répond.
Factor completely 2002-11-21
Shelley pose la question :
these two questions are to be factored completely but i have no idea how to factor them
  1. (x-4y) 2 - 3(x-4y) - 4
  2. x 6 + y 6

Penny Nom lui répond.
Filling A swimming pool 2002-11-21
Sarah pose la question :
A swimming pool is being filled by three pumps. Alone pump A would take 6 hours, pump B would take 3 hours, and pump C would take 3 hours. If all three pumps are used to fill the pool, what fraction of the process is pump A.
Penny Nom lui répond.
The volume of a juice jug 2002-11-21
Edward pose la question :
I try to find the measurement for a juice jug. I have the height of the jug and need the jug to hold 2.5 Liter of juice. Can you help me out with the formula.
Penny Nom lui répond.
Performance reviews 2002-11-21
Lara pose la question :
Perhaps you can help.

He's doing performance reviews at work.

The average performance review is 3.92 on a 5.0 scale. This person would receive a 3.5% raise for next year.

The highest performance review is 4.9 and this person would recieve a 6.0% raise for next year.

How do I solve for the other performance review numbers.


Penny Nom lui répond.
What percent is the same as three eighths? 2002-11-21
Katelin pose la question :
What is the percent of three eight's?
Penny Nom lui répond.
Composites, primes, factors and common factors 2002-11-20
Connie pose la question :
My son can't remember what a composite number is, what a prime number is and the explaination of factors and common factors. Help!
Penny Nom lui répond.
Differentiating inverses 2002-11-20
Amy pose la question :
f(x)= x3+x+1, a=1 find g'(a) (g = f -1). I am having trouble finding g(a).
Penny Nom lui répond.
4 x abcd = dcba 2002-11-20
A student pose la question :
Say you have a four digit number (e.g. abcd) and you multiply the number by 4. The answer you get will be the reverse order of the number you started with (dcba). What is the number? The four digits (a,b,c,d) cannot be the same number or cannot be repeated.
Penny Nom and Claude Tardif lui répond.
abc,abc 2002-11-20
Pam pose la question :
Prove or disprove that "every number of the form abc,abc (where a, b, and c represent digits) is divisible by 7,11, and 13"
Penny Nom lui répond.
Round to hundredths 2002-11-19
Brittany pose la question :
Can u tell me how to do a problem like this:

35 divded by 4.8= Round to hundreths.

Penny Nom lui répond.
Why is 5 divided by 1/7 greater than 5 divided by 2/3? 2002-11-19
Elizabeth pose la question :
  1. Without performing the division, explain why 5 divided by 1/7 is a number greater than 5 divided by 2/3.
  2. Is the least common multiple of two prime numbers always their product? Why or why not?

Diane Hanson and Penny Nom lui répond.
The horse race 2002-11-19
Pat pose la question :
The Horse Race Three horses run a race. In how many different ways can the three horses finish the race if ties are allowed?
Penny Nom lui répond.
A cubic 2002-11-18
Jessica pose la question :
"For what values of the constant p does f have 3 distinct real roots?" The function is f(x)= x3 - 6x2 + p, where p is an arbitrary constant.
Claude Tardif and Penny Nom lui répond.
Gears and ratios 2002-11-17
Matt pose la question :
if gear A has 12teeth and Gear B has 16teeth and gear C has 10teeth and gear A turns 40 times how many times will gear C turn
Penny Nom lui répond.
The 24 game 2002-11-16
Michael pose la question :
Hello, my name is Michael and I am in elementary school .. We have a game we play in math class called 24 game. In it each card has 4 numbers on it. Each number can only be used once, in any order, using multiplication, subtraction, division, or addition. We are stuck on one and wondered if you could help. The four numbers are 10-9-16-4. And they must equal 24. Any clues?
Penny Nom lui répond.
A 40% markup? 2002-11-15
Amy pose la question :
Please help? I own a basket and bouquet company, I have two retail stores with a markup of 40% on the price of the items I sale to them. I do not understand their conversion chart and I hope you can help me.

A bouquet that I sale for $12.50 wholesale to the retail is marked up at a rate of 1.675 or (40%). I do not understand how the calculation of 1.675 is arrived at ... how is this 40%. I was told to multiply my wholesale price of $12.50 X 1.675 and I would arrive at the markup price of 40% the retailer would sale the item for.


Penny Nom lui répond.
The product of two consecutive numbers is 41 more than their sum 2002-11-15
A mother pose la question :
THE PRODUCT OF TWO CONSECUTIVE NUMBERS IS 41 MORE THAN THE SUM OF THE NUMBERS. WHAT ARE THE NUMBERS?
Penny Nom lui répond.
The substitution method 2002-11-15
A student pose la question :
Solve by using the substitution method.

x = 3y - 1
x + 2y = 9


Penny Nom lui répond.
A pattern in a table 2002-11-14
Thamar pose la question :
how do you solve for pattern in a table like

the top row is261217z
the bottom row is9131924blank

question ask in each blank space write a rule to find the next number in the table

Penny Nom lui répond.
Algebra 2002-11-13
Carol pose la question :
I am a confused parent trying to help my dau hgter solve some math problems and I need help.

3[x-4]=27


Penny Nom lui répond.
For what divisors can you get a remainder of 8? 2002-11-13
David pose la question :
When dividing a 3-digit number by a 1-digit number, for what divisors can you get a remainder of 8?
Penny Nom lui répond.
The volume of water in a hose 2002-11-13
David pose la question :
I trying to find out how much water 500 ft of 3/4 inch hose will hold. I'd also like to know how you figured the answer.
Penny Nom lui répond.
Subdividing a circle 2002-11-11
David pose la question :
Say you have a cirlcle.

Then you draw 2 dots on the circle.

Then you connect the dots with lines.

The circle is divided into 2 parts.

If you do the same with 3 dots and connect each dot to each dot with a line then you get a circle with 4 parts.

4 dots with lines connecting all (6 lines) = 8 parts....


Claude Tardif lui répond.
Fuel consumption 2002-11-11
Guy pose la question :
When a car is driven 'normally' the feul consumption is 7.5 per litres per 100km. On a particular journey the car was driven in 'hard' and the consumption changed to 9.1 litres per 100km. Fuel cost 80p per litre. Calculate:

a) The extra feul consumed.
b) The extra cost of feul, in pounds, for the journey when the car was driven in 'hard'.

Penny Nom lui répond.
Radicals with fractional radicands 2002-11-11
A student pose la question :
how do I simplify radicals with fractional radicands?

ex. 7sqrt(2) + sqrt(50) - 2sqrt(18)

10sqrt(3/5) - 24sqrt(5/3)

3sqrt(2/9) + 1/2sqrt(32) + sqrt(9/8)


Penny Nom lui répond.
x intercepts 2002-11-10
Laura pose la question :
Find the x intercepts for the graph of the equation.

x 2 - x - 12 = 0


Penny Nom lui répond.
(93+n)+158=93+(28+158) 2002-11-10
Parents pose la question :
(93+n)+158=93+(28+158)
Penny Nom lui répond.
A bus is 60% occupied 2002-11-09
Joe pose la question :
A bus with a seating capacity of 60 people is 60% occupied. At the next stop one-third of the people get off the bus and 3 people get on the bus. The bus is now ___% occupied.
Penny Nom lui répond.
Three bags of marbles 2002-11-08
A student pose la question :
I have 3 bags of marbles

1 bag is labeled blue; 2nd bag is labeled red; 3rd bag is labeled blue & red

all the bags are mismarked

your job is to take one marble from 1 bag look at it and correctly label all the bags


Penny Nom lui répond.
Prime numbers 2002-11-08
Lonna pose la question :
Is 2 a prime number or not??
Why is 1 not considered a prime number?

Penny Nom lui répond.
Two tanks of water 2002-11-08
A student pose la question :
A 2000 L tank containing 550 L of water is being filled with water at the rate of 75 L per minute from a full 1600 L tank. How long will it be before the two tanks have the same amount of water?
Penny Nom lui répond.
Cubic centimeters 2002-11-07
Rita pose la question :
Was in emergency room yesterday-MD aspirated 40cc of fluid from my knee--what does a "cc" equate to?
Penny Nom lui répond.
G = 3H - 5 2002-11-07
Kash pose la question :
G=3H-5, for H solve for the given variable
Penny Nom lui répond.
The identity property 2002-11-07
Stephanie pose la question :
I am a student teacher this semester in the third grade. I was looking at our math competencies and saw that we needed to teach the identity property. Is this the same as the distributive property? If not, what is it?
Penny Nom lui répond.
Chisanbop 2002-11-07
Paul pose la question :
I'm trying to find the book/books that explain this system? I have one small book that explains the very beginning of the system, but covers only about 10 to 20%. I'v tried several book sellers and have had no luck.
Diane Hanson lui répond.
Substitution 2002-11-06
John Paul pose la question :
I took a math test last week, and there was a problem which the teacher checked as incorrect. It was:

Solve: (a)RcTc=360;(b)RmTm=480;(c)Rm=2Rc; (d)Tm+Tc=15

I solved the problem and I got the following values for each variable.

For Rc=40 For Tc=9
For Rm=96 For Tm=5

I don't see nothing wrong, but the teacher checked it as wrong. Could it be a checking mistake?


Claude Tardif lui répond.
Determining a parabola 2002-11-06
Shelley pose la question :
let (0,3) and (1,9)and (-1,1) be given points in a parablola. Determine a b and c
Penny Nom lui répond.
What is nth term? 2002-11-06
Joga pose la question :
What is nth term:

First sequence:
2, 4,7,11, 16, nth term

Second sequence:
4,10, 28, 82, nth term


Penny Nom lui répond.
18m-11+ -7 2002-11-06
Sophia pose la question :
what is 18m-11+ -7 (m = to 12)?
Penny Nom lui répond.
A house's selling price 2002-11-05
Tanisha pose la question :
a CERTAIN REAL-ESTATE AGENT RECEIVES $6 FOR EVERY $100 OF A HOUSE'S SELLING PRICE. HOW MUCH WAS A HOUSE SOLD FOR IF THE AGENT $10,725._
Penny Nom lui répond.
Compass points 2002-11-05
Mhairi pose la question :
I was asked this in maths but I am not sure if it is geography. Name all the compass points? We have been given 8 but he told us there is more and we have to name them.
Chris Fisher lui répond.
The percentage grade of that hill 2002-11-05
Cathy pose la question :
If there is an 80ft climb over a kilometer(about 3280ft) what is the percentage grade of that hill?
Penny Nom lui répond.
An octagon of perimeter 1,000 meters 2002-11-05
Stephen pose la question :
my son has to work out the area of a octagon with a outside perimeter of 1,000 metres,
Penny Nom lui répond.
Clown has eight steps to climb 2002-11-05
A mom pose la question :
I'm a parent of a grade two student. What is the best way to help my son figure out a math comprehension problem?

Clown has eight steps to climb, is shown in a picture with front foot on third step and behind foot on first step. Each time he climbs three steps, he falls back two. How many times did he have to climb up to reach the top.

Should I get him to do a line graph or math equations. On his own he came up with the answer seven. I think the answer is six. I did 0+3=3, 3-2=1, 1+3=4 and so on, In think my why is alittle confusing to him. Is there a simplier why to explain it to him.


Diane Hanson lui répond.
A twelve-volume set of encyclopedias 2002-11-04
Ron pose la question :
A novice librarian shelved a twelve-volume set of encyclopedias in the following order from left to right. Volumes 8, 11, 5, 4, 9, 1, 7, 6, 10, 3, 12, and 2. Using her system, where will volume 13 go?
Penny Nom lui répond.
Rounding 27.27 2002-11-03
A parent pose la question :
If you have a problem 27.27 and you need to round to the first 7 the answer would be 27

Would 27.0 be acceptable as well or is it completely wrong.


Penny Nom lui répond.
Mathematics and Music 2002-11-01
Hannah pose la question :
I am looking for a science fair project to compare math and music and how they relate. If you have any project ideas for me, they would be greatly appreciated.
Walter Whiteley lui répond.
How would you find the length of the chord? 2002-10-31
A draftsperson pose la question :
If given the length of an arc and the distance from the midpoint of the arc to the midpoint of a chord, how would you find the length of the chord and the radius of the arc. The chords endpoints are the same as the the arcs endpoints.
Penny Nom lui répond.
A coin is tossed 11 times 2002-10-31
A student pose la question :
There are 2 people that are playing a game in which a coin is tossed 11 times. The first player gets a point for a toss of heads. The 2nd player gets a point for a toss of tails. whoever gets 6 points wins. Suppose that so far the first player has 2 points and the second player has 4 points. What is the probability that the first player wins the game?
Andrei Volodin and Penny Nom lui répond.
Mrs. Klein has been losing 1 pound a week for the last year 2002-10-30
Brett pose la question :
On her diet, Mrs. Klein has been losing 1 pound a week for the last year. Her husband weighs 110 pounds more than she does now. If his weight is twice what her weight was 6 weeks ago, how much does mrs. Klein weigh now?
Penny Nom lui répond.
An isosceles triangle 2002-10-30
Stan pose la question :
What two different base lengths can an isosceles triangle have with sides on both remaining at 13 inches? How do I show this?
Paul Betts and Peny Nom lui répond.
A triangular prism 2002-10-30
Daniel pose la question :
I was wondering what a triangular prism was.
Diane Hanson lui répond.
How many empty seats are there? 2002-10-29
Ronnie pose la question :
Three new students arrived in class. Teacher says there are 210 ways you can set. How many empty seats are there in the classroom? After new student are assigned seats, how many empty seats will remain?
Penny Nom lui répond.
Variance 2002-10-29
Ade pose la question :
I am trying to solve a standard deviation question, I have 30 data points to use, should I group the data before solving for variance or should I just use the raw data.
Andrei Volodin lui répond.
Simplifying Variable Expressions 2002-10-28
Erika pose la question :
i would like to ask you a mathematical question on Simplifying Variable Expressions. The question is 2(n-4)+3.
Penny Nom lui répond.
Jimmy's hits 2002-10-27
Patty pose la question :
One seventh of Jimmy's hits were doubles
12.5% of his hits were homeruns
Jimmy had 82 singles
He did not have any triples

How many hits did Jimmy have? (Be sure to include the equation that represents the number of hits)

Penny Nom lui répond.
10 hours before 7:15 2002-10-27
Jessica pose la question :
It is evening 7:15. What time would it be 10 hours earlier?
Penny Nom lui répond.
An identity? 2002-10-27
Jenna pose la question :
I can't prove
 
1-sinQ     1 ---- = tanQ + --- 1+sinQ      cosQ 

Penny Nom lui répond.
The four colour theorem 2002-10-27
Rhonda pose la question :
is there an actual equation for the four colour map theorem??? i cannot find it anywhere!! if so can you give a breif description on how it works!!
Penny Nom lui répond.
x 4 + x 5 = 100 2002-10-27
Bill pose la question :
One of my students has stumped me. He asked how to solve the equation 4 x + 5 x = 100

All I can think of are graphing methods to get an approximate solution. What am I missing?


Harley Weston lui répond.
What are the digits? 2002-10-24
Ebenezer pose la question :
There are three digits. The middle digit is zero and the sum of the first and last digits are is 13. When the number is reversed it is increased by 297. What are the digits?
Penny Nom lui répond.
Averaging grades 2002-10-24
Richard pose la question :
I'm using a grading program for the first time this year. (ok, that's not a question) I require my students to record their grades in a Scorekeeper when they get them back. I'd like to know if my students can keep up with averaging their grades just as the grading programs automatically averages them when I put them in the spreadsheet.
Penny Nom and Claude Tardif lui répond.
How many trees were planted in March? 2002-10-20
Allison pose la question :
The number of trees planted by the Alpine Nursery in April was 3 more than twice the number of trees planted in March. If 71 trees were planted in april, write and solve an equation to find how many trees were planted in March.
Penny Nom lui répond.
Is a square a rectangle? 2002-10-20
Nona pose la question :
Are squares rectangles? Third grade math teacher told a student this was true. Grandmother needs confirmation on this!
Claude Tardif and Harley Weston lui répond.
At the zoo 2002-10-20
A student pose la question :
The number of adults at the zoo was 2/9 the number of children. there are 700 more children than adults. The number of men was four times the number of women. The number of girls was four times the number of boys. Find the total nymber of men and boys at the zoo.
Penny Nom lui répond.
Simplify 2002-10-19
A student pose la question :
well i need to simplify this problems out and i cant do it so here is one
 3x^2+6x-45 ------------ = 3x^2+21x+30 

Penny Nom lui répond.
Exponential notation 2002-10-19
Ivy pose la question :
I understand how to figure out for example 4 to the power of 3,what I don't understand is how to figure it out using both negative numbers and negative exponents,as an exaple -4 to the power of 6 and what makes this different that (-5) to the power of 7,please help me if you can.I am an adult taking correspondence and finding it quite frustrating.
Penny Nom lui répond.
Is it a prime? 2002-10-19
JV pose la question :
6x to the third power plus 5x plus 15, is that prime or not prime, and whichever it is, how can you prove it? ya dig?
Claude Tardif lui répond.
Use each digit 1-9 only one time each,... 2002-10-19
Megan pose la question :
Use each digit 1-9 only one time each, divide the numbers into 3 groups, make one 2 digit number, one 3 digit number, and one 4 digit number. There are 6 combinations of these numbers in which you can multiply the 2 digit and 3 digit number together to get the 4 digit number (using each digit 1-9 one time each). What are they!!!!!!!!!????????????
Claude Tardif lui répond.
An identity in trigonometry 2002-10-17
Alex pose la question :
I really need help with proving this identity. (1+cosx+sinx)/(1+cosx-sinx) = secx + tanx
Penny Nom lui répond.
The orthocentre 2002-10-17
Elsie pose la question :
  1. Find the orthocentre of the triangle with vertices at A(-3,4), B(10, -3) and C(3,-2).

  2. Find the distance of point X(3,8) from the line that passes through Y(-2, -2) and Z (3, -2).

Chris Fisher lui répond.
The repetition of doing many straight forward problems 2002-10-16
Dan pose la question :
I am the father of a very bright 9 year old girl. She is very interested in math and she grasps concepts very quickly. I am concerned that she may become bored with the repetition of doing many straight forward problems. Her current math teacher has her working in a challenging math book and she is doing 3+ digit multiplication. She misses 2 or 3 out of ten of these problems due to simple addition errors. Should she continue to practice these problems until she can get them all correct? Or, should she move on?
Kathy Nolan and Claude Tardif lui répond.
Integers in real life 2002-10-15
Rica pose la question :
What are the real life usages of integers?
Peny Nom lui répond.
A sale price 2002-10-15
Chester pose la question :
A jacket is on sale for 32% off. Find the original if the sale price is $89.00
Penny Nom lui répond.
6% grade 2002-10-15
Micheal pose la question :
When I am driving down the road and see a sign that says for example steep grade ahead 6% grade etc etc what does this mean?
Penny Nom lui répond.
Two problems 2002-10-14
Seçkin pose la question :
i am from turkey i am a teacher in a collage i have two difficult question which i havent solve yet these are very important for me....
Claude Tardif lui répond.
A functional equation 2002-10-14
Rob pose la question :
Let f be a function whose domain is a set of all positive integers and whose range is a subset of the set of all positive integers with these conditions: a) f(n+1)>f(n)

b) f(f(n))=3(n)

Claude Tardif lui répond.
Two problems 2002-10-14
Eva pose la question :

a) How many different equivalence relations can be defined on the set X={a,b,c,d}?

b)Show that 6 divides the product of any 3 consecutive integers. I know it is true that 6 divides the product of any 3 consecutive integers. However, i have problem showing the proof.


Leeanne Boehm and Penny Nom lui répond.
Pythagoras in three dimensions 2002-10-14
Miki pose la question :
A room is 6m long, 5m wide and 3 m high. Find the distance from the corner of the floor to the opposite corner of the celing.
Peny Nom lui répond.
Three algebra problems 2002-10-13
Veronica pose la question :
Solve the following inequality:

5(xsqured-4)/(xto the 5th(2x-5)to the 3rd) < or equal 0

Solve the following equations for all roots

square root of x+2=-1+square root of 2x+3

what's ZERO FACTOR PROPERTY???

The hypotenuse of an isosceles right triangle is 7cm. long. Determine the lenghts of the other sides.


Leeanne Boehm lui répond.
Tree diagrams 2002-10-12
Denean pose la question :
  1. For lunch, students can choose juice or milk; hamburger or pizza; and a banana or apple. How many lunch combinations can the students make?

  2. In an experiment, Monty can use paper towels or cloth. He can choose red, green, or yellow food coloring. How many combinations are there?

Penny Nom lui répond.
Statistics 2002-10-11
Ed pose la question :
Suppose 25 percent of all U.S. workers belong to a labor union. What is the probability that in a random sample of 100 U.S. workers, at least 20 percent will belong to a labor union?
Claude Tardif lui répond.
Kilometers to miles 2002-10-09
A student pose la question :
how many miles are in 16 kilometers?
Leeanne Boehm lui répond.
Nixon, Jefferson, and Madison 2002-10-08
Lisa pose la question :
The longest-lived US presidents are John Adams(age90), Herbert Hoover (also90), and Harry Truman (88). Behind them are James Madison, Thomas Jefferson, and Richard Nixon. The lattter three men lived a total of 249 years, and their ages at the time of death form consecutive odd integers. For how long did Nixon, Jefferson, and Madison live?
Penny Nom lui répond.
8 squares from 12 sticks 2002-10-08
A student pose la question :
If you have 12 sticks the same size, how do you make them into 8 squares?
Claude Tardif lui répond.
Baseball, basketball and football 2002-10-08
Debbie pose la question :
The school newspaper is interviewing 6th grade students to see what sports they follow regularly on TV. Of the 70 students interviewed; 40 enjoyed basketball; 40 enjoyed baseball; 40 enjoyed football; 20 enjoyed basketball and football; 22 enjoyed baseball and basketball; 27 enjoyed football and baseball; and 12 enjoyed all three sports. How many students out of the 70 interviewed didn't follow any one of the three sports?
Leeanne Boehm, Penny Nom and Walter Whiteley lui répond.
A complex quadratic 2002-10-06
Michael pose la question :
I would like to know, how to solve this Complex number: quadratic equation. ix 2 + x -i = 0
Harley Weston lui répond.
Relatively prime 2002-10-04
Natasha pose la question :
I really need help with this middle level math question. My little brother is asking me and I have no clue what the answer is. Explain what it means when two numbers are negatively prime. (?)
Kathy Nolan and Penny Nom lui répond.
$100 is split between four guys. 2002-10-03
Stephan pose la question :
$100 is split between four guys. A,B, C, and D. How much money does if person get if B has four more dollars than A, C has 8 more dollars than B, and D has twice as much money as C?
Penny Nom lui répond.
Rational expressions 2002-10-03
Ashley pose la question :
1/x(squared) + 5/xy
Penny Nom lui répond.
Exponent 0 2002-10-02
Debbi pose la question :
can you please tell me what the exponent 0 is (i.e. 70)
Penny Nom lui répond.
The interrelations of the propositions in Euclid I 2002-10-01
Rob pose la question :
I'm a student at St. John's College in Santa Fe New Mexico, are school is devoted to the great books and we're now reading Euclid's Elements in english and Attic Greek. We have an assignment to show a frequency or flow chart of how all the propositions of book one are interrelated.
Chris Fisher lui répond.
Two rate problems 2002-09-30
Rebecca pose la question :
  1. There are two small holes in the bottom of a tub filled with water. If opened, one hole will empty the tub in three hours; the other will empty it in six hours. If both holes are opened at the same time, how long will it take to empty the tub?

  2. An airplane flies 400 miles per hour in calm air. It can cover 900 miles flying with the wind in the same time that it can cover 700 miles against the wind. What is the speed of the wind?

Penny Nom lui répond.
A geometry problem 2002-09-29
Sonia pose la question :
Given AB||CD; m a. Find the measures of
b. Is there enough information for you to conclude that

Penny Nom lui répond.
0.99999... 2002-09-26
Erica pose la question :
Yesterday in my 8th grade math class we were being taught how to convert a Repeating Decimal into a fraction. Since I, for some odd reason, seem to understand math better than the rest of my classmates, i began to drown out my teachers explaination for the rule. While she was about half way through with explaining mixed decimals i came up with an unsolvable question. Like I said before, I understand how to turn a repeating decimal into a fraction, but how would I turn a repeating .9 into a fraction? We all know it would equal 9/9, but doesn't 9 over 9 also equal 1? Even though it comes very close to one, it never really equals one. I'm very confused about this and i would love it if you could clear this up for me.
Penny Nom lui répond.
Proof by induction 2002-09-26
Pooh pose la question :
Use induction to show that

1 2 + 2 2 + .....+n 2 = (n 3)/3 + (n 2)/2 + n/6

Paul Betts lui répond.
Painting a car 2002-09-24
A student pose la question :
Dan can paint a car in 4 hours. Luke can pain the same car in 6 hours. Working together, how long would it take them to pain the same car?
Penny Nom lui répond.
Number play 2002-09-24
Julie pose la question :
Organize these numbers and the operations so that each equation is correct. Use each coice only once per equation.

36 18 12 6 - + ( ) /

_________________________ = 22

_________________________ = 41

Claude Tardif lui répond.
Dividing fractions 2002-09-23
Angie pose la question :
When I was taught to divide a fraction, I was told to multiply the reciprocal. Many times I find I can just divide the fraction, and it saves all the simplifying after.

For example, 4/6 x 9/14 divided by 2/4

I would say 4x9divided by 2=18 over 6x14divided by 4 =21, so the answer is 18/21 but if I multiply the reciprocal, I would end up with 4x9x4 over 6x14x2 which equals 144/168.

So, why are we taught to do it this way? Is it necessary?


Chris Fisher lui répond.
A cone that is cut off at the top 2002-09-23
Stuart pose la question :
I have to work out the dimensions and arcs of a cone that is cut off at the top.

I.e Top diameter is 33mm to bottom diameter is 43mm and the depth is 80mm

Are you able to work what the flat of this cone would be as I need to design within the flat area and then have it cut out.

I really need to know what the flat of it is before it is cut and curled to form the above cone.


Walter Whiteley lui répond.
Solving an equation 2002-09-22
Emanuel pose la question :
how do u solve these problems?:

30/x=7+ 18/2x

3m+1/4 = 2- 3-2m/3

Penny Nom lui répond.
Ceiling 2002-09-22
Joe pose la question :
Does the ceiling of a number mean the ceiling of 1.3 is 2 and
the ceiling of 1.5 is 2 and
the ceiling of 1.8 is 2.

Or the ceiling of 1.3 is 1.5?


Penny Nom lui répond.
A max/min problem 2002-09-21
Evelina pose la question :
A window is the shape of a rectangle with an equilateral triangle on top. The perimeter of the window is 300 cm. Find the width that will let the maximum light to enter.
Penny Nom lui répond.
Fractional exponents 2002-09-20
Jill pose la question :
The problem is with fractional exponants:
10 1/3 mult. by 10,000 The 1/3 is an exponant of 10.

Penny Nom lui répond.
The entire earths' population would fit in the state of Texas 2002-09-18
Roz pose la question :
I have been told that the entire earths' population would fit in the state of Texas and each person would have 1/2 acre. Is this true.
Chris Fisher lui répond.
How long will it be before you reach your friend? 2002-09-16
Margaret pose la question :
Your friend runs at 8 miles per hour and you drive at 40 miles per hour, hence the diatance between you is decreasing at 32 miles per hour. You firend left 2 hours before you so how far has he gone in that 2 hours? How long will it take for the distance between you to decrease to 0 miles if the distance is decreasing at 32 miles per hour?
Penny Nom lui répond.
A Circle is evenly divided into six equal triangles 2002-09-16
Marilynn pose la question :
A Circle is evenly divided into six equal triangles leaving an area between the outside of the circle and the one side of the triangle. This area is measured as 3.14. What is the length of the radius, one line on the triangle?
Paul Betts lui répond.
A million sheets of 30 cm long paper 2002-09-15
Jennifer pose la question :
if you put a million sheets of 30 cm long paper end to end, how many kilometer long would the paper be from begining to end?
Penny Nom lui répond.
Formulating equtions 2002-09-14
Theresa pose la question :
Hello. In math class we have to formulate equations for certin questions for extra credit. We are allowed to ask anyone and anyone can do it for us and explain it to us. Could you please do that? Here are the questions
  1. Jordan has 3 times as much money as Reva. Together they have $44. How much money does each have?

  2. The Tigers played 48 games. They won twice as many as they lost. How many did they win?

  3. There are 900 students in Sewickley Academy. There are 20 more girls than boys. How many girls are there?

  4. A board 400 cm long is cut into 2 pieces. One piece is 66 cm longer than the other. Find the lenght of the shorter piece.


Penny Nom lui répond.
Sums of evens 2002-09-14
Rosa pose la question :
How do I find a geometric way to easily compute sums of consecutive even numbers 2 + 4 + 6 + ....
Leeanne Boehm and Harley Weston lui répond.
Mixing solutions 2002-09-13
Margaret pose la question :
In a chemistry laboratory the concentration of one solution is 10% hydrocholoric acid (HCl) and that of a second soulution is 60% HCl. How many mL of each should be mixed to obtain 50 mL of a 30% HCl solution??
Penny Nom lui répond.
Base 5 numbers 2002-09-13
Vera pose la question :
? how do you change a base 10 number to base 5
Penny Nom lui répond.
How many dominoes? 2002-09-13
A student pose la question :
Dominoes are split into two halves. If you were allowed up to 6 dots on each half, how many options of dominoes could you get?
Penny Nom lui répond.
The number of decimal places in 1 over a power of 2 2002-09-12
Allan pose la question :
Does anyone notice that the maximum number of decimal place of the number 2 dividing 1 and its increment (4, 8, 16...etc) is the same as the power of number 2? eg. 22=4, thus the max number of decimal of 1/4=0.25 which is 2 decimal place and 2 is the number of power of 2 take 64 as example: 26=64, and take 1/64=0.015625 which has 6 decimal place (and is the power 6)

Is there such a law in math? If yes, can you tell me what it is? Or is this my discovery?


Paul Betts lui répond.
Use a 4 four times 2002-09-12
Amanda pose la question :
The question is what is if you can only use a 4 four times and get the answer 12, 10, and 6
Claude tardif lui répond.
7+8+9+...+1000 2002-09-11
Shirley pose la question :
My question is what is the formula for adding up numbers when you don't start with number 1? For example 3 + 4 + 5 + 6 = 18. But how could you arrive at the answer without adding all the numbers?
Penny Nom lui répond.
The quadratic formula 2002-09-11
Kathleen pose la question :
im having a problem trying to understand quadratic formulas can u please help me

i have problems like

3x2 - 4x - 11 = 0 how do i work out that problem? i have the formula written down but it doesnt seem to register for me.

Penny Nom lui répond.
The sum of the first one hundred even numbers 2002-09-10
Arthur pose la question :
What is the sum of the first one hundred even numbers?
Penny Nom lui répond.
A fish weighs 10 pounds more than half its weight. 2002-09-10
Rebecca pose la question :
A fish weighs 10 pounds more than half its weight. How much does it weigh?
Penny Nom lui répond.
The factor theorem 2002-09-10
Yael pose la question :
Prove (x - a - b) is a factor of x3 - a3 - b3 - 3ab (a + b)
Penny Nom lui répond.
How do start from 2700 and get 35% back out? 2002-09-09
Dennis pose la question :
2000 x 0.35 = 700 + 2000 = 2700
How do start from 2700 and get 35% back out? If I have 2700, how do I figure out that 35% of 2000 is 700 and adding the two them together will get me 2700?

Penny Nom lui répond.
A linear function 2002-09-09
Chad pose la question :
If y = 9x - 13 does it represent a linear function? And if it does what is its slope and is it a direct variation?
Peny Nom lui répond.
The community garden 2002-09-08
Michele pose la question :
Bryce, Duanne, Juliana and Sonya share a 40ft by 48 ft rectangular portion of the community garden in the neighborhood. With this space each has their own rectangular garden plot.

-Bryce is the only one with a square plot. its are is 1/2 the area of Duanne's -The area of Bryce's plot is 2/3 the area of Julianna's plot. Their plots have one side in common.

-Sonya's garden has an area twice that of Julianna's garden.

What are the dimensions of each person's garden plot?


Leeanne Boehm lui répond.
Algebra 2002-09-08
Heather pose la question :
This question is from an 8th grade Algebra classs. I am a parent asking for help to explain to my child. Q: d=25t2.
Leeanne Boehm lui répond.
Mean, median and mode 2002-09-08
Ramona pose la question :
  1. How do you calculate the mean, median, and mode?

  2. what are each of their definitions?

Leeanne Boehm lui répond.
Weighing pumpkins 2002-09-08
Jennifer pose la question :
Suppose five pumpkins are weighed two at a time in all possible ways. The weights in pounds are recorded as 16, 18, 19, 20, 21, 22, 23, 24, 26, and 27. How much does each individual pumpkin weigh. NO FRACTIONS!
Penny Nom lui répond.
The area of a triangle 2002-09-07
Phill pose la question :
How do you find the area of a equilateral and other triangles?
Penny Nom lui répond.
Sanding a wooden block 2002-09-07
Wanda pose la question :
If a wooden block, 2in height, 3in width, and 6in length is sanded and 1/8 of an inch is removed from the top and from the bottom, how much is the volume of the block decreased?
Penny Nom lui répond.
Subsets of the Real Number System 2002-09-07
Christine pose la question :
In looking for a French equivalent of the word "integer", I found that the word seems not to actually exist in French, and that Canadian schools use the term "natural number" to describe what we have been trained to call "whole numbers," while using the term "whole number" to describe what we have been trained to call "integers."
Claude Tardif lui répond.
Social security numbers 2002-09-06
Chris pose la question :
How many different number combinations are there for the social security system? We know that there are only a certain ammount of combinations available and the current US population is at 281 million. The number system should include as many nine digit combinations as possible using the numbers 0-9 in multiple different spots.
Penny Nom lui répond.
I am a 3 digit number. 2002-09-06
Jasmine pose la question :
I am a 3 digit number. My last digit is 3 times my first digit. My firat digit is twice my middle digit. What numbers am I? There are at least 2 correct answers?
Paul Betts lui répond.
8,27,64 . . . 2002-09-05
Mike pose la question :
We have been trying with no luck all night to complete the following math pattern (next 3 entries) 8,27,64 . . . Any ideas??
Penny Nom lui répond.
What really is pi? 2002-09-05
Rachel pose la question :
what really is pi? 3.1444
Penny Nom lui répond.
Dan is 4 inches taller than Mike. 2002-09-04
A parent pose la question :
Dan is 4 inches taller than Mike. Together they are 8 feet 8 inches tall. How tall is each boy in feet and inches.
Penny Nom lui répond.
1/8 in decimal form 2002-09-04
A student pose la question :
explain how you put 1/8 in a decimal form
Penny Nom lui répond.
Intercepts 2002-09-04
Tamara pose la question :
Why is it that the x intercept the value of y is 0 and at the y intercept the value of x is 0?
Leeanne Boehm lui répond.
1, 2, 4, 8, 16, 32, etc. 2002-09-04
Ginger pose la question :
I've been working with finding the nth term for a few weeks, and i can't seem to figure this one out!

1, 2, 4, 8, 16, 32, etc.


Leeanne Boehm lui répond.
Monthly rent 2002-09-04
Al pose la question :
How do you figure monthly rent if the charge is 11.00 per sq. ft. and there are 1,000 sq. feet?
Leeanne Boehm lui répond.
A limit 2002-09-03
Circe pose la question :

Lim 3x 3+ax+a+3 /(x 2+x-2), X->-2


Penny Nom lui répond.
Addends can be grouped differently but the sum does not change 2002-09-03
Jodia pose la question :
I have been searching the web for over an hour & a half now for the answer to the following question:

The _____ states that addends can be grouped differently but the sum does not change.


Penny Nom lui répond.
A schedule for a fantasy football league 2002-09-01
Steve pose la question :
i am in a ten(10) team league, split evenly into two five team divisions. we play a thirteen(13) game schedule and would like to play each team in your own division twice, and each team in the other division once. according to my rudimentary mathematics that equals 13 games. a good schedule should look somthing like this: team 1-5 = division 1 team 6-10 = division 2 team 1 should play teams 2-5 twice and teams 6-10 once.
Claude Tardif lui répond.
A group of 9 2002-08-31
William pose la question :
what is the mathmatical name for a group of nine like a group of 3 is called 'triplets'
Penny Nom lui répond.
Proof by induction 2002-08-31
Tabius pose la question :
Use mathematical induction to prove that the following formulae are true for all positive integers:

a) 1 + 3 + 5+...+(2n - 1) = n 2

b) 2 n > n.


Penny Nom lui répond.
How many cubic feet are in a cubic mile? 2002-08-30
William pose la question :
How many cubic feet are in a cubic mile?
Penny Nom lui répond.
A square of tiles 2002-08-30
Rosa pose la question :
How do I go about finding a formula for the number of tiles I would need to add to an arbitrary square to get to the next sized square?
Penny Nom lui répond.
38-10+12divided by4multiplied by 16 2002-08-30
Brenda pose la question :
my math question is as follows: 38-10+12divided by4multiplied by 16=?
Penny Nom lui répond.
< and > 2002-08-30
Kelsey pose la question :
What is the origin of the greater (>) than and less (<) than signs?
Harley Weston lui répond.
A solution to an equation 2002-08-28
A student pose la question :
How do you determine whether a pair of numbers is a solution for an equation?

If you could identify the specifics steps I need to take to determine whether it is a solution or not would be appreciated! Thanks

i.e. x-4=0 Pairs of numbers as possible solutions (4,7) (3,4) (0,-4).


Penny Nom lui répond.
Student to teacher ratio 2002-08-28
A student pose la question :
central middle school has 2470 students and the ratio of students to teachers is 26:1 how many new teachers are needed to reduce this to 19:1?
Penny Nom lui répond.
Mixing gas and oil 2002-08-27
Sherry pose la question :
how do I calculate the correct fuel ratio for a boat motor? 50:1 the oil containers only say how many ounces to add to 5 gallons of fuel to make a 50:1 ratio.(13 ounces to 5 gallons of fuel) I have a 20 gallon tank so what if I add 11.6 gallons of fuel, what formula would I apply to get the correct measurement of oil to add?
Penny Nom lui répond.
Common Denominator 2002-08-26
Slobodanka pose la question :
What is a Common Denominator?
Penny Nom lui répond.
The tangent to a curve and the tangent of an angle 2002-08-26
A teacher pose la question :
Is there a relationship between the tangent of a curve(line touching the curve at one point) and tangent (the trigonometric function)?
Chris Fisher lui répond.
Divisibility of 5 2002 2002-08-25
Simon pose la question :
I need to ask you a question if 5 2002 and 3 2002 are divisible by 26.
Penny Nom lui répond.
Express 5120 as a sum of consecutive numbers 2002-08-25
Todd pose la question :
Express 5120 as a sum of more than 1 consecutive number.
Leeanne Boehm lui répond.
When does an inequality represent the area above the line? 2002-08-25
Tamara pose la question :
How do you determine that an inequality represents the area above the line and when do you include the line in the solution?
Penny Nom lui répond.
Cubic yards of concrete 2002-08-24
Michael pose la question :
if you have a 10" dia pipe 8' long how many cubic yards would it take to fill with concrete. how how would you go about figuring it out.

and also if you would how many cubic feet, cubic inches in a cubic yard. i know you don't need to answer, seeing i am not in school, but would appreaciate it.


Penny Nom lui répond.
Sets and elements 2002-08-22
Dianne pose la question :
I want to know why its okay to say that, for example, 6 is an element of the set of integers, but you get counted off for saying that the set of 6 is an element of the set of integers. How come?
Judi McDonald lui répond.
Gallons in a cylindrical tube 2002-08-21
Heidi pose la question :
IF I HAVE A 12" DIA TUBE WITH 1/4" WALL AND 72" IN LENGTH HOW MANY GALLONS OF WATER WILL THIS HOLD
Penny Nom lui répond.
Parallelograms 2002-08-21
Moorthy pose la question :
11 parallel lines are intersected by another 9 parallel lines.Then how many parallelograms are formed?
Walter Whiteley lui répond.
The 20 kilometer walk 2002-08-20
A student pose la question :
THE 1996 OLYMPIC GOLD METAL WINNER FOR THE 20 KILOMETER WALK WAS JEFERSON. HIS TIME WAS 1HOUR, 20 MIN,AND 7SECONDS. HIS TIME WAS NOT GOOD ENOUGH TO BEAT THE WINNER IN 1988 BY JOSEF. HIS TIME WAS 1 HOUR,19 MIN, 57 SECONDS. WHAT WAS THE WALKING RATE OF EACH PERSON?
Penny Nom lui répond.
Sole Mates Shoes 2002-08-19
Robert pose la question :
Sole Mates Shoes has expenses of $9,592 per month. What must the store's total income be if it is to make a profit of 12%?
Penny Nom lui répond.
When is 1! + 2! + 3! + ... + x! a square? 2002-08-19
Sarathy pose la question :
Solve :

1! + 2! + 3! + ... + x! = y 2

How do i find the solutions ?


Claude tardif lui répond.
Combination locks 2002-08-17
John pose la question :
How many combinations of three number codes can occur with a standard combination lock? The range of possible numbers is 0-39 which allows 40 different possible choices each turn of the dial. Each combination requires exactly three numbers (i.e. three turns of the dial). E.g. 35-40-5. Allow for reuse of the same number three times e.g.10-10-10. I don't think there is any preference shown for certain number combinations. Can you explain how the total is derived? Someone at the YMCA this week put this question to me and I gave an answer but I am not sure I am right--so I have come to you.
Penny Nom lui répond.
Volume of a sphere 2002-08-16
Rahul pose la question :
How do i find the volume of a sphere without the knowledge of calculus?
Walter Whiteley lui répond.
Distance in 3-space 2002-08-16
David pose la question :
The question is: how do I figure out the distance of one object in 3D space to another object in 3D space? I have an object at say x = 5.872, y = 2.876, and z = 7.290; and the other object is at x = 1.129, y = -8.213, and z = -11.127. I have been suggested to use the pythagorean theory on this, but since there are three variables, I don't understand how.
Penny Nom lui répond.
Probability 2002-08-16
Chris pose la question :

There are two possible outcomes for a random event, A and B.

The probability of A being the outcome is 63%, and B 37%.

What is the likelihood that B will be chosen twice, consecutively? Three times, ten?


Andrei Volodin lui répond.
Variable expressions 2002-08-15
Brittany pose la question :
I am just learning variable expressions. My homework is to write a variable expression for each word phrase;

example :

the number of minutes in s seconds
the cost of x cartons of juice at $.75 each
And etc.

I don't understand it

Penny Nom lui répond.
A paper model of a cone 2002-08-14
Bruce pose la question :
I have made a paper model of a cone, cut a sloping section, and removed the top. I have drawn the major and minor axis on the paper surface of the section. The major axis is not symmetrical about the minor axis. To me, this is not an ellipse. To me, an ellipse is a tubular section, because this gives a symmetrical major axis. What is your opinion?
Walter Whiteley and Chris Fisher lui répond.
The circumference of a 72 2002-08-14
Linda pose la question :
What is the circumference of a 72" diameter circle?
Penny Nom lui répond.
Two equations 2002-07-26
Derek pose la question :
1. 3x + 2y = 4
2. -7x + 2y = 24

finding x and y.


Penny Nom lui répond.
Some inequalities 2002-07-25
A student pose la question :

1)-5 <= -3X+1 < 1

2)4X-2 < 6 OR X+2 > 9


Penny Nom lui répond.
Musical Scales 2002-07-24
Terence pose la question :
Given that there are 12 notes in a musical octave, what is the maximum number of musical scales possible within that octave, if each scale has a minimum of 5 notes and a maximum of 9 and we start all the scales from the same note?

In case you don't know anything about music, a scale is a progression of notes where you start on a specific note and end on that same note an octave higher. There are twelve different notes between these two similar notes. Which notes you choose to play determine the sound of the scale. Anything less than five notes would not make for a very interesting scale. Anything more than nine and you would be playing almost 'every' note in the scale, not leaving much room for distinction in how you organize these notes.

I assume you first have to figure out the maximum number of variations possible in a 5-note scale (with 12 notes at your disposal). Then do the same for a 6-note scale, then a 7-note, then an 8-note, and so on. Then add up the results. How to find this maximum number of variations for each scale size though is what I don't know.


Leeanne Boehm lui répond.
20 men dig 40 holes in 60 days 2002-07-24
Lindsey pose la question :
20 men dig 40 holes in 60 days. So, 10 men can dig 10 holes in how many days?
Penny Nom lui répond.
x + 5 + x, if x = 4 2002-07-23
Elisa pose la question :
x + 5 + x, if x = 4
Leeanne Boehm lui répond.
7th grade math lesson plans 2002-07-23
Peter pose la question :
Where can I get samples of 7th grade math lesson plans and curriculum for the whole year?
Leeanne Boehm lui répond.
As much greater than 47 as it is less than 105 2002-07-23
Joe pose la question :
To find the number in question you need to find the number exactly half-way between 47 and 105. Another way of thinking about the number that is half-way between two other numbers is as the average of the two numbers given.
Leenaan Boehm lui répond.
Domain of a function 2002-07-20
Andy pose la question :
I'm having difficulty in finding the domain of

1/(x2 -2x + 4)

one over x squared minus 2 x plus 4.


Penny Nom lui répond.
Percentage 2002-07-20
Sally pose la question :
If 20% of 100 is 80, then why is the percentage difference between 80 and 100 25%.
Penny Nom lui répond.
Place six numbers around a triangle 2002-07-19
Monika pose la question :
I need to place six numbers around a triangle, as such that one number is on each corner, and one number on each side making three numbers in one line, adding up to two hundred exactly. The number I have to use are, 40, 50, 60, 70, 80, 90. I have to use each one once, there for, each number cannot be repeated.
Claude Tardif and Chris Fisher lui répond.
Can you make up a word that adds up to 1000000? 2002-07-19
Adrie pose la question :
My question is elementary and I am a student Please help me with the following conundrum, as it is driving me crazy.

'When the letters in the alphabet are given values from 1 to 26 for A to Z, can you make up a word that adds up to 1000000 ( one million )-used as a multiplication?'

Like 'cat' would be 3*1*20 = 60

Claude Tardif lui répond.
Order of operations 2002-07-18
Danna pose la question :
I would like to know how to solve this type of problem; I already have the answer.

Problem: 2 [5 (4 + 6) - 2] = 96

Also, what do you call this type of problem? Thanks a lot.


Penny Nom lui répond.
Division by zero 2002-07-18
James pose la question :
Why is division by zero undifined (i have to proof that division by zero is undifined)
Chris Fisher lui répond.
A rope around a post 2002-07-15
Nic pose la question :
My daughter who is in the 10th grade asked me this ?, you have a pole 45 inches high, 22inches around. You have a rope 1/2 thick, how many feet of rope would you use to go from top bottom of pole to top.
Penny Nom lui répond.
A probability problem 2002-07-12
Yvonne pose la question :
What is the probability of 38 people choosing the same five options, given a choice of 15?

Perhaps you could just give me the formula with an explanation.

I am an English teacher doing educctional research, but am stuck because I don't have the math experience to help me.


Andrei Volodin lui répond.
Two cubes 2002-07-12
Vanessa pose la question :
The edges of a cube are 50% as long as the edges of another cube. What percent of the volume of the larger cube is the volume of the smaller cube?
Peny Nom lui répond.
Pigs in pens 2002-07-10
Shannon pose la question :
A farmer has 21 pigs and 4 pens, he must put an odd number of pigs in each pen, how does he do it?
Penny Nom and Chris Fisher lui répond.
The Praxis II test 2002-07-09
A student pose la question :
I am taking the Praxis II test and I can't seem to answer certain styles of questions. Please help!!!!!!
  1. In a class of 29 children, each of 20 children has a dog and each of 15 has a cat. How many of the children have both a dog and a cat?

  2. If there are exactly 5 times as many children as adults at a show, which of the following CANNOT be the number of people at the show? a. 102 b. 80 c. 36 d. 30

  3. In order to estimate the population of snails in a certain woodland, a biologist captured and marked 84 snails there were then released back into the woodland. Fifteen days later the biologist captured 90 snails from the woodland, 12 of which bore the markings of the previously captured snails. If all of the marked snails were still active in the woodland when the second group of snails were captured, what should the biologist estimate the snail population to be based on the probabilities suggested by this experiment? a. 630 b. 1,010 c. 1040 d. 1080.

Paul Betts lui répond.
A polygon inscribed within an ellipse - Part 2 2002-07-08
Steven pose la question :
I recently sought your advice about a problem that I have been working on for eight years or so concerning a polygon inscribed within an ellipse. I think that I may have confused matters by the way in which I put the question and hope that the enclosed diagram will clear matters up. In the ellipse below I have drawn three chords inscribed within one quadrant ( this would pertain to a twelve sided figure within the whole ellipse). These chords are exactly the same length as each other, for example if the major axis of the ellipse was 360 and the minor axis 240 I have worked out that a twelve sided figure would have sides of 78.2487. However I worked this out empirically with a method that could only be described as gruelling I would be most grateful if you could tell me of a method that would work for any ellipse and any number of sides.
Chris Fisher lui répond.
The base 10 multipliction table 2002-07-07
A student pose la question :
These are two questions from Math for Elementary Teachers and they have me stumped.

You have two coins that are worth 30 cents. One of the coins is not a nickel. What are the two coins?

The product of the diagonals of any 2x2 matrix in the base 10 multiplication table are equal. Why?


Penny Nom lui répond.
A box that holds 22.4 liters 2002-07-07
Jon pose la question :
How do I find the measurements required to make a box that holds 22.4 liters of something?
Penny Nom lui répond.
Equivalence relations on a set of cardinality n 2002-07-06
Siddhartha pose la question :
what is the no. of equivalence and transitive relations on a set of cardinality n?
Penny Nom lui répond.
An equalateral polygon inscribed within an ellipse 2002-06-30
Steven pose la question :
How would you calculate the length of one of the sides of an equalateral polygon (of n sides) inscribed within an ellipse ( of any eccentricity ) where all of the vertices exactly touch the perimeter of the ellipse?

I know that when the eccentricity is zero ( i.e a circle ) the formula: r * (sin(180/n) * 2) will suffice. But what about when the eccentricity is greater than zero?


Chris Fisher lui répond.
Math test 2002-06-28
Dustin pose la question :
I have a really important placement test to take in 2 weeks. I need to have a strong comprehension of algebra and I have't taken a math class in about for years.

I'm 24 and am going back to school. I want to get ahead and into math 96, and must pass this test to do that.

Do you know of a book or a wab site that can teach me a few formulas that will give me the edge I need. If I have the right text for the job i'll study day and night to pass.


Leeanne Boehm lui répond.
Future value 2002-06-27
Susan pose la question :
If one were to invest $115 a month for 20 years and expect a 4% annual return, what is the value of this money in 20 years?
Leeanne Boehm lui répond.
What is the next term? 2002-06-21
A student pose la question :
What is the next term in the sequence:

1, 5, 14, 30.....


Penny Nom lui répond.
Counting 2002-06-21
Rachel pose la question :
How many different numbers of 2 different digits each can be formed using the digits (1,3,5,7,9)?

How many triangles are formed by the vertical of a regular hexagon?

Penny Nom lui répond.
Jack and Jill wrote letters 2002-06-19
Angel pose la question :
jack and jill each bought a stationary
# of sheets of paper in each box were the same
# of envelopes were the same
jill wrote letters consisting of 3 pages
jack wrote letters consisting of 1 page

when they wrote all letters jill had 50 envelopes left and jack had 50 sheets of paper left how many pieces of paper and how many envelopes?

Leeanne Boehm lui répond.
Integrating x^x 2002-06-18
Jeremy pose la question :
I am a student at the University of Kansas and I am wondering if there is a general anti-derivative for x x (i.e. the integral of x x dx)? I've looked in a bunch of Table of Integrals and have found nothing (can you guys find it?), so I'm sort of wondering if this may be a research type question.
Claude Tardif lui répond.
A good rule of thumb when driving 2002-06-13
Lisa pose la question :
A good rule of thumb when driving is that you should be about one car length away from the car in front of you for every 10 miles per hour that you are travelling. Suppose you follow this rule perfectly (so you are exactly the correct distance away). You are waiting at a stop light with your front bumper just touching the car in front of you. The light turns green and the car in front accelerates at a constant rate "r". Calculate how you should accelerate in order to follow the rule.
Penny Nom lui répond.
The cross country team 2002-06-12
Denae pose la question :
In cross country, a team's score is the sum of the first five finishers on the team. The captain of the team finished 2nd in the meet. The next four finishers on the team placed in consecutive order. The team score was 40. in what places did the other members finish?
Penny Nom lui répond.
An equilateral triangle 2002-06-11
Sarah pose la question :
Hi. My name is Sarah. I'm a secondary student taking a Math 30C course by correspondence. The question has two parts.

The first part is: Draw an equilateral triangle XYZ. Draw the altitude from X to YZ. Choose any point P inside the triangle or on the triangle. Draw perpendiculars from P to the sides of the triangle. The Second part is:

Measure the altitude h and the 3 perpendiculars s, t, and u to the nearest mm. Repeat as many time as is necessary until you can state a generalization concerning h, s, t, and u. If you could help me, it would be greatly appreciated.

Penny Nom lui répond.
Drawing cards 2002-06-11
Ed pose la question :
What is the probability of drawing without replacement from a standard deck of 52 cards the following 5 card hand ...... the ace of spades, 2 tens and 2 face cards

Solution 1: 1/52 x 4/51 x 3/50 x 12/49 x 11/48

Solution 2: Using Combination theory ..... (1C1 x 4C2 x 12C2) divided by (52C5)

Can you help us understand which answer is correct and why the other is not?


Penny Nom lui répond.
Successive coefficients in the nth row of Pascal's Triangle 2002-06-10
Tim pose la question :
There is a formula connecting any (k+1) successive coefficients in the nth row of Pascal's Triangle with a coefficient in the (n+k)th row. find this formula.
Penny Nom lui répond.
0.63 of an acre 2002-06-08
Sherry pose la question :
how many square feet are in 0.63 of an acre
Penny Nom lui répond.
Regular polyhedra 2002-06-07
Sandra pose la question :
The other day a colleague and I were talking about polyhedra. Is regular a term applied to polyhedra or just polygons? If so, then what would define a regular polyhedron? Would it mean all faces are regular or would it mean that all faces are identical and regular? That is, could a pyramid with equilateral triangles for lateral faces and a square base be considered regular or must the base also be an equilateral triangle?
Chris Fisher lui répond.
The mean distance travelled 2002-06-07
A student pose la question :
If Rosalia travels 1000 km
Sheree travels 280 km
Daniel travels 50 km
Mica travels 200 km
Connor travels 500 km
Eric travels 250 km
Hillary travels 300 km

What was the mean distance travelled?

How do you arrive at the answer?


Penny Nom lui répond.
Constructing the square root of 3 2002-06-07
Allan pose la question :
I am a Math 7/8 teacher. I was wondering how you would show a student how to find the exact location of the square root of three on the number line using just a compass and a straight edge.
Penny Nom lui répond.
Perimeter 2002-06-05
Tava pose la question :
I'm a grade four student from St. Mary school. In class we've been dicussing perimeters. So this is what we did; First we each got a piece of paper in the shape of the geoboards and our teacher told us to find as many different shapes of area of 12 square units. During this time we were given to find perimeters of shapes that had twelve square units one of our classmates discovered the biggest perimeter possible with twelve square units of 26 units. Another classmate discovered the smallest perimeter of fourteen units. Here's a question: Why are all the shapes with fourteen units all the same shape? and why are all the shapes with twenty-six units can be different? After we found the biggest and smallest shapes our teacher told us we each had to find at least one shape of the biggest and smallest. After we each foud a shape with a perimeter of twenty-six and fourteen we had to find different shapes with different perimeters. During that time we discovered different perimeters.

What we found was fourteen all the way up to twenty-six, but they all went by two's. Why didn't they count up by 14, 15, 16, 17, 18 etc? I think it's because the area is an even number. See if you added one "block" or "square" to it you always add three because at least one of the sides is together with another side. Whyare all the perimeters all even numbers?


Penny Nom lui répond.
A polynomial 2002-06-05
Melissa pose la question :
I'd like to know what is a polynomial( the definition and an explication)? And is 7x a polynomial? and why?
Penny Nom lui répond.
The area of a circle 2002-06-03
Jessica pose la question :
I am doing a maths assigment for university, which is aimed towrds primary school students(k-6). I was wondering if you could give me some information as to how I could describe to students the rule for finding the area of circle, using a circle cut up into equal sectors (like a pizza). I know it has something to do with the fact that you can make these shapes into a parallelogram, but I am a bit uncertain as to how I can express this idea clearly and articulately to students.
Penny Nom lui répond.
Ratios and weights on Neptune 2002-06-03
Janice pose la question :
The ratio of an object's weight on earth to it's weight on Neptune is 5:7. How much would a person who weighs 150 pounds on earth weigh on Neptune.
Penny Nom lui répond.
Ounces and cubic centimeters 2002-05-30
Martin pose la question :
How many ounces are in 600cc of liquid?
Penny Nom lui répond.
11........1 2002-05-29
Un eleve pose la question :
Démontrer que tout nombre impair non multiple de 5 admet un multiple de la forme:11........1
Claude Tardif lui répond.
Conics 2002-05-29
Brooke pose la question :
Which conic cannot be generated by an intersection of a plane and a double napped cone?
Chris Fisher lui répond.
Overlapping circles 2002-05-29
Naman pose la question :
There are two circles, big circle with radius R and small one with radius r. They intersect and overlap in such a way that the common area formed is 1/2 pi r 2 (half the area of the small circle) If r=1, find the Radius of the big circle (R)?
Harley Weston lui répond.
The sum of the areas of two regular decagons 2002-05-27
A parent pose la question :
The sum of the areas of two regular decagons is 39 square inches, and their radii are in the ratio of 2:3. Find the area of the larger decagon.
Paul Betts lui répond.
Linear programming 2002-05-27
Jes pose la question :
A machine shop makes two parts, I and II, each requiring the use of three machines, A, B, C. Each Part I requires 4 minutes on Machine A, four minutes on Machine B and five minutes on machine C. Each Part II requires five minutes on Machine A, one minutes on Machine B and six minutes on Machine C. The shop makes a profit of $8 on each Part I and $5 on each Part II. However, the number of units of Part II produced must not be less than half the number of Part I. Also each day the shop has only 120 minutes of machine A, 72 minutes of Machine B, and 180 minutes of Machine C available for the production of the two parts. What should be the daily production of each part to maximize the shop's profit?
Claude Tardif lui répond.
Cubic feet and cubic yards 2002-05-27
John pose la question :
how do you find the cubic feet/cubic yard of area 10 feet wide by 15 ft long by 2 inches high
Penny Nom lui répond.
One-fourth of a number is added to one-third of the same number 2002-05-26
A student pose la question :
When one-fourth of a number is added to one-third of the same number, the result is 28. What is the number?
Penny Nom lui répond.
A spotlight shines on a wall 2002-05-25
Barb pose la question :
A spotlight on the ground shines on a wall 12m away. If a man 2m tall walks from the spotlight toward the bldg at a speed of 1.6 m/s, how fast is his shadow on the bldg decreasing when he is 4m from the bldg?
Penny Nom lui répond.
A schedule for 24 golfers 2002-05-25
John pose la question :
I am working on a schedule for 24 golfers. 6 groups of 4. I have 8 golf days (twice per week for a month).

Ideally, I would like to schedule all 24 golfers in 6 different groups of 4 on each day. Here is the catch.....no golfer in any group can be grouped togther more than once. Every group of 4 each day will have 4 new golfers that have never played together before. Is this possible?


Chris Fisher lui répond.
| n + 4 | + | 3 - 2n | = 16 2002-05-24
Randall pose la question :
I don't seem to be able to solve this: | n + 4 | + | 3 - 2n | = 16
Penny Nom lui répond.
Blood donations 2002-05-23
Fiza pose la question :
One particular high school encourages students to donate blood. the high school gym is set up for purpose. the distribution of blood type in north america is as follows.

Type O:44%
Type B:10%
Type A:42%
Type AB:4%

(a) what is the probability that the first two people in the line up have the same type of blood?

ANSWER: I donn't know how many people are in the line. so how can I answer this question.

(b) what us the probability thar none of the first five people in the line up have type AB blood?


Andrei Volodin lui répond.
3 radians subtends an arc of 27 meters 2002-05-22
Kyle pose la question :
In circle O, a central angle of 3 radians intercepts an arc of 27 meters. Find the number of meters in the length of the radius.
Penny Nom lui répond.
Bob swam across a river 2002-05-22
Torri pose la question :
Bob swam across a river 420 ft wide. A strong current carried him 580ft downstream as he swam. Find x, the distance bob actually swam.
Penny Nom lui répond.
Telephone banking 2002-05-22
Fiza pose la question :
To use telephone banking to pay bills, the customer has to enter the last three digits of each bill. the numbers 0 to 9 can be used. if the number happened to be the same on more tan one bill, the customer has to enter the first three digits as well.

(a) what is the probability that a person has 2 bills to register with the same last three digits?
ANSWER:P(2 bills to register)=1/10P3 1/(10!/7!), 1/(10*9*8)=.001389

(b) what is the probability that a person with 10 bills to register has at least 2 bills with the same last three digits?
ANSWER:P=1/(10*10*10) =0.001


Andrei Volodin lui répond.
The average of two averages 2002-05-22
RJ pose la question :
in a class with 22 students, the average garde on an exam was 68%, in another class with 32 students, the average grade on the same exam was 78%, what was the overall for the two classes? round your answers to the nearest whole number.
Leeanne Boehm lui répond.
Un octogone 2002-05-21
Yves pose la question :
Si j'ai un octogone ayant 8 pieds de diamètre,comment fais t'on pour trouver la mesure de un de ces cotés et quel est cette grandeur.
Claude Tardif lui répond.
A popular television game show 2002-05-19
Amrita pose la question :
On a popular television game show, contestant must first answer a question by placing 4 given events in ascending or desending order in the quickest time.

(a) if a contestant does not know how any of the events should be arranged, how many different ways could the question be answered?

Answer: 4!= 24

(b)a contestant has to arrange the events that correspond to A, B, C, and D. one contestant is positive that event D follows directly after avent B, but does not know about the other s. how many different ways could this contestant arrange the letters A, B, C, and D, list the possibility

Answer: which I didn't get


Penny Nom lui répond.
Probability and investment 2002-05-19
Bally pose la question :
Investors do not invest all their money in the investment predicted to be the best beuause it is too risky. an investor holds shares in three independent cmpanies. company A, Company B, compnay C. an analyst predicts the probability of profit increases for each company as follows. Company A:0.70 Compamy B:0.50 Compnay C:0.65

(a) If the analyst's predictions are true, what is the probability that all three comapanies show a profit incresse?

ANSWER: I try using vin diagram but it did'nt work, I dont know any other ways to solve this question

(b) if the analyst's predictions are true, what is the probability that at least one comany shows a profit increase?


Andrei Volodin lui répond.
Conditional probability 2002-05-19
Manny pose la question :
In a certain school, it is known that 80% of the students use the internet for school projects, 60% use e-mail on a regular basis, and 90% use the internet for school projects or for e-mail on a regular basis. a student from this school is selected at random

Determine thge probability that the student used e-mail, given that the student used the internet for school projects.
ANS: how can i solve this question by useing the vin diaagram


Andrei Volodin lui répond.
Flying with the wind 2002-05-19
SaraJean pose la question :
It takes 6 hours for a plane to travel 720 km with a tail wind and 8 hours to make the return trip with a head wind. Find the air speed of the plane and the speed of the wind current.
Penny Nom lui répond.
How far apart are the transmitters? 2002-05-18
Jeff pose la question :
A ship at sea is 70 miles from one transmitter and 130 miles from another. The measurement of the angle between the signals is 130 degrees. How far apart are the transmitters?
Penny Nom lui répond.
Find the angle measures 2002-05-18
Amanda pose la question :
In triangle ABC; the measure of angle A is 20 degrees more than twice the angle B. The measure of angle C Is five times angle B. Find the angle measures.
Penny Nom lui répond.
Chord length 2002-05-17
Ashlie pose la question :
How do you find the chord length of one section of a chord if you only have the diameter length and the other whole chord length.

WV is the diameter and equals 16. XY is perpendicular to it, and equals 10. They intersect at pt. Z. I need to know what WZ equals. Please help!


Penny Nom lui répond.
On which assignment did I do better 2002-05-17
Denise pose la question :
I have 2 writing assignments in class. The first assignment, which had a mean of 10 and a standard deviation of 2, I got a score of 12. The second assignment had a mean of 18 and an s.d. of 3, I got a 21. I need to know which assignment did I do better, relative to my classmates?
Andrei Volodin lui répond.
Sequences that agree on their first four terms 2002-05-16
Mike pose la question :
Are there two formulas that define sequences that agree on their first four terms, but differ on the fifth term and all succeeding terms?
Chris Fisher lui répond.
Thank you gifts 2002-05-15
Navi pose la question :
Children usually attend birthday parties where a thank you gift is given to the children who attent the party. a family likes to hand out books at thank-you gifts.

(a) One child invited to the party is given 2 books as gift. if there was 15 different books to choose from, how many diffrent gifts were possible?

Answeer: I did this way 15C2=105

(b) if the 15 books consisted of 8 nonfiction and 7 fiction, how many diffrent gifts were possible if at least 1 of 2 books were fiction?


Penny Nom lui répond.
Day care 2002-05-13
Sonam pose la question :
In many familes, both parents work. as a result, there is increasing need for day care. data was collected; and in one year in Canada, approximately 32% of children aged 0 to 11 years were in day care for at least 20h per week.

(a) what is the probability, in a random poll of 60 children form the age of 0 to 11, that more than 15 children are in day care at least 20 h per week? nearest tenth of one %

ANSWER:
P(children are in daycare at least 20h)= 60/60C14 = to the answer

(b) what is the probability, in a random pool of 60 children that fewer than 20 are in day care at least 20 h per week?

ANSWER:
P= 20/60= 33.3% stay in day care for 20h per week,

I dont know if these answers are right please help me out.


Andrei Volodin lui répond.
What is Calculus About? 2002-05-13
A student pose la question :
I am a high school senior and have to write an essay answering the question "What is Calculus?" I need some ideas. Thanks
Walter Whiteley lui répond.
A game of dice 2002-05-13
Mika pose la question :
To play a game a dice is rolled to see who plays first. four players are going to play the game. what is the probability that at least two people roll the same number?

ANSWER: P(least 2 people roll the same #)=number of player/total outcome

P = 4!/4C2 = 24/4C2 = 4 the answer is 40%


Andrei Volodin lui répond.
An award ceremony 2002-05-13
Mika pose la question :
Five students are equally qualifide their school at an award ceremony. two students will be randomly chosen to go to the ceremony.

(a) if Tony is one of the five student, what is the probability that he will be chosen?
Ans: 2/5C2=0.2 which is 20%

(b)Tony's friend, Allecia, who was also eligible to go, has been chosen. what is the Tony's probability of being chosen after he learns that allecica is going:
Ans: 1/5C1=0.2

I think the answes are wrong please help me with these questions


Andrei Volodin lui répond.
Some algebra 2002-05-11
A student pose la question :

/x - 2 ^4/x = 8

/ = square root sign
^ = 4th root of x

also, dividing
2x3 -3 -6x
__________
4 + 2x

the 2x3 is 2x to the third


Penny Nom lui répond.
A ski trip 2002-05-10
Navi pose la question :
A ski trip at the school has been arranged. there are 30 students that have paid for the trip and 6 parents that have volunteered to chaperone. to transport the students and parents easily, they are to be divided into two group. one group has 10 students and 2 parents, and the other group has 20 students and 4 parents.

(a) How many different group of 10 students can be formed?
ANSWER:

(b) How many different groups consistinmg of 10 students and 2 parents are possible?
ANSWER:

(c) kelly is one of the students going on the ski trip, and kelly's mother volunteered to be one of the chaperones. kelly's mother would prefer to be in the smaller group and not in the same group as kelly. if this wish is honoured, how many ways can the smaller group and its chaperones be chosen?
ANSWER:


Harley Weston lui répond.
The law of cosines and obtuse angles 2002-05-09
Bryant pose la question :
The question that I am pondering is that I need to derive the law of cosines for a case in which angle C is an obtuse angle.
Penny Nom lui répond.
A rectangular marquee 2002-05-07
Alyaa pose la question :
a marquee with rectangular sides on a square base with a flat roof is to be constructed from 250 meters square of canvas. find the maximum volume of the marquee. i find this topic so hard
Harley Weston lui répond.
Forming a committee 2002-05-06
Navi pose la question :
A committee is to be formed to investigate what activites teenagers have available in small communities. the committee is to have 7 members, chosen randomly form interested community members. there are 10 parents, 5 teenagers, and 4 adult without children who have all expressed an interest in serving on the committee.

what is the probability that the adults without children are all on the committee?


Andrei Volodin and Penny Nom lui répond.
Oven lights 2002-05-06
Manny pose la question :
Q.A manufacturer of stoves has to buy oven lights from from two diffrent companies because one company alone cannot meet its demand. the manufacturer purchases 60% of the oven lighs from comany A and the rest form Company B. Past experiecnce shown that 1% of Company A's oven are defective oven and 2.5% of Company B's oven light are defective.

Determine the probability that a defective oven light is supplied by company A.


Andrei Volodin lui répond.
How will I use calculus in my career? 2002-05-06
Meridith pose la question :
How will I, hopefully a future secondary mathematics teacher, use calculus in my career if I'm not teaching calculus?
Walter Whiteley lui répond.
3 = -2x 2002-05-05
Timothy pose la question :
My question is 3 = -2x

How do I isolate the variable here?


Penny Nom lui répond.
A probability tree 2002-05-04
A student pose la question :
Karl and Naomi roll three dice. Karl gives $10 to Naomi if the number 5 turns up once, twice or three times. Naomi gives Karl $3 in all other cases. A) construct the probability tree for this situation.

B) Does Karl have an advantage in this game? Justify your answer.
My problem is I am unfamiliar on how to draw this probability tree and seem to be having a lot of difficulties, when you have a chance please answer this math problem and get back to me with the results.

Penny Nom lui répond.
An identity(?) 2002-05-02
A student pose la question :
prove identity sin 2x/1-sinx= secx+1/secx


Paul Betts lui répond.
8/13*26/27 2002-05-01
Arias pose la question :
8/13*26/27=
Penny Nom lui répond.
Square numbers 2002-05-01
Sally pose la question :
Is one considered a square number?
Penny Nom lui répond.
oneths 2002-04-30
Logan pose la question :
why are there tens-tenths hundreds-hudreths, but not oneths

if that made no sense then how about this why does everything have two ways of saying things like tens and tenths but not a oneths


Claude Tardif lui répond.
Factor 12x^2 - 20x - 8 2002-04-30
Crystal pose la question :
Factor Completely: 12x2 - 20x - 8
Penny Nom lui répond.
The Dugout, Don's Basement, Cd Corner,... 2002-04-30
A student pose la question :
The Dugout, Don's Basement, Cd Corner, Harry's Deli, Bill's Software, Anne's Footwear, and Joanne's House cleaning.

The gift certificates are each in multiples of $5. There is a $100 range in the value of the gift certificates, which start at $25. The mean value of all seven gift certificates is $80, and the median and mode are both $70.

The certificate from The Dugout is worth the most and the one from Joanne House cleaning is worth the least.

The total value of the gift certificates from CD Corner, Harry's Deli, and Anne's Footwear is $270, but Anne's Footwear certificate is worth $50 more than the one from Harry's Deli. The Cd Corner gift certificate is equivalent to the mean for this group of three.

What is the value of the gift certificates from each store?


Penny Nom lui répond.
What's the next term? 2002-04-29
A student pose la question :
Find the nth term for the following:

1) 12, 30, 56, 90, 132
2) 6, 30, 84, 180, 330
3) 8, 15, 24, 35, 48
4) 10, 17, 26, 37, 50
5) 24, 40, 60, 84, 112
6) 24, 60, 120, 336, 504

Please show the FULL working out.


Penny Nom lui répond.
Trains and cracker boxes 2002-04-29
Lindsay pose la question :
1)Two trains are 250 miles apart on the same track heading towards eaxh other at 7AM- The first train travels at 55mph, the second at 75mph. At what time would they crash?

2)A cracker box measures 12 by 2 by 18 inches. The company wants to double the amount of crackers, but keep the shapes the same[similar] Find the new length[nearest tenth of an inch]


Penny Nom lui répond.
Conversion of units 2002-04-29
Matt pose la question :
I am having trouble finding a workable equation for the following problem, particularly the conversion of two systems of measurement.

The question states that there are 27 grams of salt in a kilogram of seawater. And it asks how many tonnes (1 tonne = 1000 kilograms) of salt are there in one cubic kilometer of ocean. It also says that the density of seawater is 1.1 g/cm3.

What is the equation and how do I figure out how many kilograms there are in a cubic kilometre?


Harley Weston lui répond.
A 6,000 gallon tank 2002-04-28
Someone with a big tank pose la question :
I was wondering if you can find out information about how much liquid fuel can fit in a 6,000 GAL. tank. Right now I do not have the exact dimensions of this tank but I will have it the 29th of April. Could you please E-mail me and let me know if you can answer this question after I have the correct specifications.
Penny Nom lui répond.
0/4 = ? 2002-04-28
Danielle pose la question :
I am embarrased to be asking this question, but... is it possible to have a fraction with a zero? For example, 0/4. This does not make sense to me and I do not know what it would be representing, other than nothing! Is it proper to express such a fraction?
Peny Nom lui répond.
A triangular prism 2002-04-28
A student pose la question :
Need the formula for the surface area of a triangular prisim?
Penny Nom lui répond.
a+b=10 and ab=40 2002-04-27
April pose la question :
What two numbers add to ten and multiply to forty?

(a+b=10, a*b=40)

I think the answer includes radicals and/or imaginary numbers.


Penny Nom lui répond.
Designing a ballot 2002-04-26
Kelley pose la question :
I want to design a ballot for four elections. Actually all the candidate races are on 1 ballot. I need to know how many different ballot styles would be needed for all of the candidates to be in each rotation an equal number of times.

For example:

  • A,B,C & D are running for mayor

  • E,F,G & H are running for congress

  • I,J & K are running for senate

  • L,M & N are running for governor

They are all on the same ballot. But in each race their name (for instance A) has to be in the #1 rotation, #2 rotation, #3 rotation, and #4 rotation for his race on this ballot an equal number of times as B,C and D.

The same goes for the other candidates for their perspective races.

How many total ballot styles will there be?


Penny Nom lui répond.
Triangular numbers 2002-04-26
Anika pose la question :
Can you please tell me what a triangular number is?
Penny Nom lui répond.
Functions and relations 2002-04-25
Erin pose la question :
Here's a few math problems that might drive a person insane ;)
  1. If 2f(x) - 3f(1/x) = x^2 what is f(2)?

  2. What are the domain and range of the following relations?
    • x^2 - 4y^2 = 25
    • 4x^2 + 9y^2 = 36

  3. The port of Swan Harbor is 200km away from Merry Town Inlet on a bearing of N50E from Merry Town. A ship leaves Merry Town at 8am and sails N15W at 15 km/h. At the same time, a second ship leaves Swan Harbour on a course of S80W at 20km/hour. How close, to the nearest km, are the two ships at 13:00?

  4. Prove the identity. 1+sinx + cosx/ 1-sinx + cosx = 1+sinx / cosx

Penny Nom lui répond.
How much of that total is G.S.T? 2002-04-24
Darlene pose la question :
If I have $1700.00 how much of that total is G.S.T?

not 1700.00 + gst

____ + _____ gst = 1700.00


Patrick Maidorn lui répond.
Arithmetic progressions 2002-04-24
David pose la question :
I have been searching everywhere for the formula to mathamatical progression.
Penny Nom lui répond.
An Olympiad problem 2002-04-23
Aurora pose la question :
I wrote a mathematical Olympiad the other day and there was one question that I could not work out.

The question was If ab = 1, bc =2, cd =3, de =4 and ea = 6, what does a + b + c + d +e =

It was a multiple choice and the answers were : 43/6; 47/6; 49/6; 53/6; 61/6 The correct answer was 61/6, but how can do you get to that answer?


Anrei Volodin lui répond.
A test drive 2002-04-23
Jennie pose la question :
At 9 A.M. a test car driving at a constant speed passes a marker 50 miles from it's starting point. At noon the car is about 130 miles from the marker. If the test drive ends at 1:30 P.M., how far will the car be from its starting point?
Penny Nom lui répond.
25m = 100 2002-04-22
Megan pose la question :
If 25m = 100, Then m equals what number?
Penny Nom lui répond.
Lines of symmetry 2002-04-22
Cindie pose la question :
How many lines of symmetry do the following figures contain?

trapezoid:

rhombus:

hexagon:

pentagon:


Walter Whiteley lui répond.
Problem solving 2002-04-20
Kathy pose la question :
  1. Zachary wanted to run the shore-to shore marathon next month, a 26 mile race from one side of the island where he lived to the other. He decided to work up to 26 miles by running five days a week for the next five weeks. Each day he'd run one mile longer than he did the day before, except for the first day of the week, when he'd run the same number of miles he ran on the last day of the previous week. He wanted his last two practice runs to be 26 and 27 miles long.

    How many miles would he have to run on his first practice run?

  2. A school just bought a new set of encyclopedias. The front and back covers are 1/8 inch thick, and the pages are 1/100 inch thick (in other words, there are 100 pages per inch). the 26 volume set has a total of 5,250 pages. If you assume there is no extra space left between books, then .........

    What length of bookshelf will the encyclopedias take up?

Penny Nom lui répond.
Solve for x 2002-04-20
A student pose la question :
solve for x.
  c-x      2x+b ----- = --------   a        c 

Peny Nom lui répond.
Cubic yards 2002-04-20
Pat pose la question :
I HAVE AN AREA 10'x6'I WOULD LIKE TO PUT LOAM ON IT 5" DEEP HOW MANY CUBIC YARDS OF LOAM DO I NEED?
Harley Weston lui répond.
An augmented matrix 2002-04-20
A student pose la question :
Hi my math teacher asked us to solve an augmented matrix. I am in twelfth grade and need help. The book we are working on is college algebra. Here it is

a+2b+c=0
2a+5b+4c=-1
a-b-9c=-5


Penny Nom lui répond.
Solving for x 2002-04-19
Susan pose la question :
I'm having a little trouble solving these equations for x. I can't seem to separate x fully from the other numbers. Please help! Here are the problems:

(2x-1)/(x-2)(x 2+3) = 0 and

y/(x+1)=z/x
Penny Nom lui répond.

Moving a triangle 2002-04-18
A student pose la question :
find the verticles of a triangle after it is translated 2 units to the left and then is reflected across the graph of y=x+2. The original verticles of the triangle are (2,0), (3,2), and (6,2).
Peny Nom lui répond.
How many different account numbers are possible? 2002-04-18
Andrene pose la question :
how many different account numbers are possible if the account numbers consist of a letter of the alphabet, followed by five numerical digits, and followed by another letter.
Penny Nom lui répond.
Arc length 2002-04-17
Vix pose la question :
Find the point on the curve r(t)=(12sint)i-(12cost)j+5tk at a distance 13pi units along the curve from the point (0,-12,0) when t=0 in the direction opposite to the direction of increasing arc length.
Harley Weston lui répond.
Ratios 2002-04-17
A student pose la question :
  1. Medication is givin at 1cc. per 20 pounds of body weight. A dog weighs 16 pounds how many ccs. of medication does the dog get?

  2. Dr. Lee wants you to prepare 1000 ml. of a 10% dextrose solution in lactaed ringers for diuresis or a patient you have a 1 L bag of lactated ringers and 500 ml of 50% dextrose for injection. How would you prpare the solution?

Penny Nom lui répond.
Related rates 2002-04-17
Molly pose la question :
A tanker spilled 30 ft cubed of chemicals into a river, causing a circular slick whose area is expanding while its thickness is decreasing. If the radius of the slick expands at the rate of 1 foot per hour, how fast is them thickness of the slick decreasing when the area is 100 feet squared?
Penny Nom lui répond.
Two algebra problems 2002-04-14
Ashley pose la question :
Question 1: For all values of a, let < a > be defined as < a > = 4a - 4 . Which of the following equals < 6 > - < 5 >? A: < 2 >
B: < 3 >
C: < 4 >
D: < 5 >
E: < 6 >

Question 2: If 5n + p = 3 and 2m - 10n = 2, what is the value of m + p?


Penny Nom lui répond.
A polynomial 2002-04-14
A student pose la question :
A polynomial function is described by the following conditions: f(x) has two real zeros at x= -2 and x= 1, each of multiplicity 2 f(x) has two complex zeros as x goes to -infinity, f(x) goes to +infinity as x goes to +infinity, f(x) goes to +infinity f(x) has a y-intercept at (0,2)

Sketch a polynomial function that satisfies the above conditions.

Write an equation for function f(x)

Write another function g(x) that also satisfies the above parameters.


Penny Nom lui répond.
How many gallons of water in a cubic foot? 2002-04-14
Richard pose la question :
I am tring to find out how many gallons of water in a cubic foot.
Penny Nom lui répond.
The vertex of a cone 2002-04-13
Callie pose la question :
Does a cone have a vertex?
Penny Nom lui répond.
The square root of four 2002-04-13
Frank pose la question :
In a recent quiz we where asked the square root of four. The quizmaster gave the answer as not only 2 but also -2. Being pedantic I queried this. Although -2 squared is 4, does it follow that the root of 4 is -2 Can you enlighten us?
Claude Tardif and Penny Nom lui répond.
The bleep test 2002-04-13
Lorraine pose la question :
I am currently undergoing training and have asked about a fitness test called the bleep test. The bleep test involves running continuously between two points that are 20m apart. These runs are done in time to a pre-recorded bleep sounds on a pre-recorded audio cassette. The time between the recorded bleeps decrease after each minute. I would like to do my own personal version for training but I have to work out the following before doing this:

I need to find out the time in-between the beeps at least for the first level so I can work out the difference for the other levels:

The information given to me for the first level is :

A 20 meter run at 8.5km/hr (how long would it take?)

Please let me know if there is any way in working out this query with the information given.


Leeanne Boehm lui répond.
Calculate profit 2002-04-13
Allison pose la question :
If I sell something for $75; and my cost is $40, I make $35 profit. How do I calculate the profit percent I made on that transaction?
Penny Nom lui répond.
Diagonals in a polygon 2002-04-10
Murray pose la question :
If you have a regular polygon with n sides and you draw all (n-3)n/2 diagonals how many intersection will they form with each other and how many sections will they devide the polygon into.
Caude Tardif and Chris Fisher lui répond.
n +1, n+2, n+3, and n+4 are all composite 2002-04-09
Jonathan pose la question :
Find the small integer n such that n +1, n+2, n+3, and n+4 are all composite
Penny Nom lui répond.
The Proof in the Pudding 2002-04-09
A student pose la question :
The host at a party turned to a guest and said, "I have three daughters and I will tell you how old they are. The product of their ages is 72. The sum of their ages is my house number. How old is each?" The guest rushed to the door, looked at the house number, and informed the host that he needed more information. The host then added, "The oldest likes strawberry pudding." The guest then announced the ages of the three girls. What are the ages of the three daughters?
Claude Tardif lui répond.
Sodding the yard 2002-04-08
Craig pose la question :
my parents want to lay sod in our back yard.

the sod cost $2.00 per square foot.

The size of our yard is 20x20 and 26x41


Penny Nom lui répond.
Area of a triangle 2002-04-07
Puzzled pose la question :
What is the surface area of a triangle 13 ft x 13 ft x 18 ft?
Penny Nom lui répond.
3/4n-6=12 2002-04-07
Diane pose la question :
I am in 6th grade advanced math and I just started Algebra. My teacher tries to explain it to me but I just can't get it. I am having difficulty understanding it. Please HELP!!! I will type a problem, if you could answer it and show your work so i can understand it that

would be great. Please explain in simple terms.

here is a couple problems I am having trouble with,

PROBLEM #1

3/4n-6=12


Penny Nom lui répond.
Composition of functions 2002-04-06
Yvonne pose la question :
In our new text book, the following question occurs: State the domain and range of g(f(x))given that f(x) = -x2 - 4 and g(x) = sqrt(x)

The range of f(x), x<=-4, is the domain of g(x). BUT, there is no solution in the Real numbers for g(f(x))= sqrt(-x2 - 4).

In the solutions it says that this is not a function and therefore does not have a domain or range. Is it a relation? Is it anything?


Claude Tardif lui répond.
Pairs of equations 2002-04-04
A student pose la question :

high school level
student is asking

y=4x x=-4y 
x+y=5 3x+2y=20   

y=x-1 3x-y=4 
x+y=3 2x-3y=-9   

x+5y=4 
3x+15y=-1 

. . . 

Penny Nom lui répond.
Two triangles 2002-04-03
Scott pose la question :
Consider 2 triangles: Triangle PMB and Triangle PLA.

Triangle PLA is contained within Triangle PMB.

Side LA is parallel to Side MB.

Point L is located on Side PM. Point A is located on Side PB.

If the ratio PL:LM = 5, then what is PB:PA ??


harley Weston lui répond.
Take It! 2002-04-03
Bryan pose la question :
You are playing Take It! for $180,00 with a total stranger. There are 180 identical balls in a big vase. Each player in his turn, reaches into the vase and pulls out 1,5,or8 balls. These balls are discarded. The player who takes the last ball from the vase wins the $180,000. A flip of the coin determines that you will go first. Are you glad? How many will you take out on the first move, and how will you proceed to win the prize?
Claude Tardif lui répond.
Common fractions to decimal fractions 2002-04-02
Natalie pose la question :
My questions are: "how can I change 23/60 into a decimal. and give my answer to 2dp."??????????

2nd question:for each of these pairs, which is bigger?

4/7 or 36%____________
3/11or 0.29____________
14/24 or 0.57___________


Penny Nom lui répond.
Pascal's Triangle 2002-04-02
Brian pose la question :
It's about (a+b)x. I remember there a triangle with numbers to remember for a faster solution. Can you please teach me?
Penny Nom lui répond.
If you conect all the vertices of a regular n-gon... 2002-04-01
Murray pose la question :
If you conect all the vertices of a regular n-gon with lines you will have (n-3)(n/2) lines inside the polygon. I want to find out how many sections these lines divide the polygon into and how many intersections they have with each other.
Claude Tardif lui répond.
Area of an octagon 2002-04-01
Someone pose la question :
What is the actual square footage of a 12' octagon?
Penny Nom lui répond.
All four eights in three consecutive hands 2002-04-01
Blair pose la question :
What are the odds against the same person holding all four eights in three consecutive hands.
Brian Alspach lui répond.
Meg's biscuits 2002-03-29
Tami pose la question :
Meg's biscuits recipe calls for 4 cups of flour for every 1.5 cups of milk. If Meg uses 6 cups of flour, how many cups of milk will she need?
Penny Nom lui répond.
The reciprocal of a decimal mixed number 2002-03-29
A student pose la question :
How do I find the reciprocal of a decimal mixed number?
Penny Nom lui répond.
Some 5 card hands 2002-03-28
A student pose la question :
From a standard deck of cards how many 5 card hands are possible consisting of a. exactly 4 hearts

b. two cards of one kind and three of another(like a full house).

Penny Nom lui répond.
100 from four 9's 2002-03-27
A student pose la question :
My teacher gave us a math problem to try and figure out and I am stumped. The problem was this.... by only using four nines, how can you get an answer of 100? You can add, subtract, multiply or divide...anything you need to do ,but you can only use four nines.
Leeanne Boehm lui répond.
If the matrix A is inverible and AB =AC, then B = C 2002-03-27
Vikki pose la question :
i hope you can help i am soooo stuck here goes:

a)

 A= 0 1 B= 1 1 c= 2 5    0 2    3 4    3 4 
A,B and c are matrices

Evaluate AB and Ac (which I can do)

then

b)
I need to prove that if the matrix A is inverible and AB =AC, then B = C. Why does this not contradict what happened in part a)?
Leeanne Boehm lui répond.

Cube roots 2002-03-26
Kathy pose la question :
My son is in 4th grade and needs to simplify the cube roots of 216, 512 and 64. How does he do this with a regular calculator or without?
Penny Nom lui répond.
A triangle in a circle of radius 6 2002-03-26
Marko pose la question :
In a circle of radius 6, a triangle PQR is drawn having QR = 8 and PQ = 10. Determine the length of PR
Chris Fisher lui répond.
A lottery question 2002-03-25
Noel pose la question :
I want to take all numbers in a Lotto game from 1 to 45 and ditribute them between 9 boxes each containing 5 numbers. Each number is used only once.
  1. What is the probability that I derive the correct combination of 5 numbers in the draw?

  2. What is the probability if I take a systems game and now distribute 9 numbers into each of 5 boxes? Once again, the numbers are used only once.

  3. Can you explain what formulae are used and how the answer is derived? Is this a distribution or combination problem? Or is it a combination of both distribution and combination?

Andrei Volodin and Penny Nom lui répond.
Unit fractions 2002-03-23
Laura pose la question :
Write 1/2 as the sum of ten different unit fractions.
Claude Tardif lui répond.
A hamburger and a soft drink 2002-03-23
A student pose la question :
A GROUP OF FRIENDS WENT OUT TO LUNCH. EACH BROUGHT A HAMBURGER AND A SOFT DRINK. TOGETHER A HAMBURGER AND A SOFT DRINK COST MORE THAN A DOLLAR. THE TOTAL COST FOR THE GROUP WAS $17.81. THERE WAS NO TAX OR TIP INCLUDED.

IF A HAMBUGER COSTS 2 CENT MORE THAN TWICE A SODA, FIND THE COST OF THE HAMBURGER.


Leeanne Boehm lui répond.
A probability problem 2002-03-23
Kate pose la question :
If I have a spinner and then spinner has the numbers 1,2,3,4 on it and it is spun 3 times, what is the probability that the spinner will stop on 4,3,and 1 ? In that order?
Leeanne Boehm lui répond.
A trigonometric identity 2002-03-22
Debby pose la question :
I am stuck on a problem and wondering if you can help?? It is: Prove the following:
sec2(X)+csc2(X) = sec2(X)csc2(X)

Harley Weston lui répond.
Mr. Byrd's drive to work 2002-03-22
Mr. Bollen pose la question :
Mr. Byrd leaves his house at 7:00am to go to work. If he drives 40 mph he will arrive 3 minutes late and if he drives 60mph he arrives 3 minutes early. At what speed will Mr. Byrd have to drive in order arrive exactly on time. Please describe how you arrived at your answer.
Claude Tardif and Penny Nom lui répond.
Range of values for standard deviation 2002-03-22
Susan pose la question :
What is the range of values for standard deviation? Is it between 0 and +3? Is it between +1 and +3?
Andrei Volodin lui répond.
What fraction of the world's motor vehicles are built in Canada? 2002-03-20
A student pose la question :
About 1/4 of the world's motor vehicles is built in Canada or the United States. About 1/5 of the world's motor vehicles are built in the United States. What fraction of the world's motor vehicles are built in Canada?
Claude Tardif lui répond.
Adding algebraic fractions 2002-03-20
Dolores pose la question :
I get totally confused with this problem. I get confused with the getting the lowest terms.

4/x-5 + -2/x -10/x^2-5x


Penny Nom lui répond.
A cone in 3 space 2002-03-20
Matthew pose la question :
Let C in R3 be the cone defined by x2 + y2 - z2 = 0

(A) Let P be the plane described by x + 2z = 1

(i) Find a description of P in terms of two parameters s and t

.
.
.

Walter Whiteley lui répond.
F = -3 + 3 2002-03-19
Jessica pose la question :
F= -3 + 3 WHAT IS F?????
Penny Nom lui répond.
A set of points in space 2002-03-18
Victoria pose la question :
Describe the given set with a single equation or a pair of equations:

The set of points in space that lie 2 units from the point(0,0,1) and at the same time 2 units from the point (0,0,-1).


Penny Nom lui répond.
24x^4 + 3x 2002-03-18
gary pose la question :
24x 4 + 3x
Penny Nom lui répond.
Interest owing 2002-03-17
Dean pose la question :
I am an investor. If I lend to someone on January 1, 1999, $1000 to be paid back interest at 2% per year (simple interest, ie not compounded), and on July 15, 1999, I lend the same person $1,500 more (total loan is now $2,500) but at 18%, and once again on October 15, 1999, I lend to the same person another $1,500, and the person pays me back the principle($4,000) and interest on January 1,2001: What is the total (principle plus interest) due me? The tougher question is: what was my blended rate of return on my total outlay of money? Is there a formula you can give me so that I can perform my own calculations?
Harley Weston lui répond.
Combinations? 2002-03-16
Sara pose la question :
A combination lock has three dials numbered 0 - 9. Give a mathematical reason why "combination" is a bad name for this type of lock.
Penny Nom and Chris Fisher lui répond.
How much olive oil? 2002-03-15
Annie pose la question :
Joe used 1/3 cup of olive oil, which was 3/4 of the amount that he had. How much olive oil did he have!
Penny Nom lui répond.
Testing a hypothesis 2002-03-14
A student pose la question :
A large distriutor of cosmetics has kept his outstanding accounts receivable to a mean age of 18 days over the past year. This average is considered a standard by which to measure the efficiency of the credit and collections department. Management wishes to check if receivables in the current month is over standard and will do this at a significance level of 0.50. A random sample of 100 accounts yields an average of 20 days with a standard deviation of 9 days. what should management conclude?
Andrei Volodin lui répond.
The square root of i 2002-03-14
Arlene pose la question :
what is the square root of i, if i=x+yi?

what is the square root of 1-i? i'm getting problems like these in which I do not understand.


Harley Weston lui répond.
3 5/8 and 2 1/4 2002-03-13
Shirley pose la question :
3 5/8 and 2 1/4 what is the percentage of 2 1/4 to 3 5/8.
Penny Nom lui répond.
15 miles at 13 miles per hour 2002-03-12
Rich pose la question :
If I were traveling 15 miles at 13 miles per hour how long will it take?
Penny Nom lui répond.
My 1978 Chevy has a 350 cubic inch engine 2002-03-11
Sharon pose la question :
If my 1978 Chevy has a 350 cubic inch engine, about what size engine would that be in liter?
Penny Nom lui répond.
x and y-intercepts 2002-03-10
A student pose la question :
I have the problem- f(x)= X-5/X2+X-6 and I have to find the vertical asymtope, horizontal asymtope, x-intercept, and y-intercept. And graph the problem. I am having problems finding the y-intercept.
Harley Weston lui répond.
The best time to teach math 2002-03-10
West pose la question :
My name is West. I teach 4th grade. I would like to know if there is any research which tells about the best time to teach math. Should it be taught in the a.m. or p.m.
Walter Whiteley lui répond.
Multiplying decimals 2002-03-10
Kaitlin pose la question :
I just recently had a test on multiplying decimals and I did not do really well on it. Only 5 kids out of 19 got a passing grade. My teacher says that she will give us a different test and we can take it again, but I'm still not sure of it. My teacher has taught me a lot and she had done a wonderful job of it but I'm just confused with where to put the decimals and stuff like that. I have a math practice workbook that I do for fun and they have nothing on decimals in it. I have checked on websites to try to find worksheets but I really couldn't find a good one. Can you please help me either give me some tips or clues or send me a worksheet.
Penny Nom lui répond.
The isosceles triangle of smallest area 2002-03-08
Lettie pose la question :
can you find the isosceles triangle of smallest area that circumscribes a circle of radius of one?
Walter Whiteley lui répond.
Percentage difference 2002-03-08
Tedd pose la question :
Can you give me the formulas for calculating percentage differences between two numbers? For example: if the first number is 10 and the second number is 15, then the second number is 50% larger than the first number. However, the formula to calculate that percentage won't work if the first number is greater than the second number as in the following example: The first number is 15 and the second number is 10, with the second number being 33.3% less than the first number. Or maybe I'm mistaken and the same formula will work in both situations.
Penny Nom lui répond.
Factor completely 2002-03-07
Taylor pose la question :
I'm supposed to completely factor this but I don't know what to do with all the variables.

a3b5 - a2b5 - 12ab5.

Does it have anything to do with b5 being a common factor or am I completely off?
Penny Nom lui répond.

A sequence 2002-03-07
Caroline pose la question :
hi, here is the problem,

1
11
21
1211
111221
_ _ 2_ _ _

we can't get the sequence of the last line ,with the 3rd number being 2,thanks


Walter Whiteley lui répond.
The square root of 2 2002-03-05
Roger pose la question :
Does two (2) have a square root or do the numbers just keep going? Are there any other numbers that behave like two when it comes to extracting the square root?
Penny Nom lui répond.
A circular wading pool 2002-03-04
Patrick pose la question :
The community of melfort is planning to build a circular wading pool in the park. The pool will cover an area of 1000m2. The building committee has decided to put a 5m cement pad around it. How much additional area will the cement pad take up?
Harley Weston lui répond.
The slope of a tangent line 2002-03-04
Ridley pose la question :
Suppose a function f(x) has the line 3x+4y=2 as its tangent line at x=5. Find f'(5).
Harley Weston lui répond.
Percentage 2002-03-03
Nathan pose la question :
I have two questions:
  1. 25% of what number is 195?
  2. 42 is what percent of 112?

Penny Nom lui répond.
Mixed numbers, whole numbers and improper fractions which are less than 2. 2002-03-03
Dawn pose la question :
Change each mixed number to a whole number and an improper fraction which is less than 2. 3 1/2 = 2 /
Penny Nom lui répond.
What number am I? 2002-03-03
Samantha pose la question :
I am an even number that has more ones than tens. My thousands digit is the quotient of 9 divided by 3 and my tens digit is the sum of 3 and 3. I have no hundreds. What number am I?......Please answer this for me...The answer I come up with is 3,060...Is this right?..
Penny Nom lui répond.
The median with ties 2002-02-27
Marcel pose la question :
What, exactly, is the proper way to determine the median of a set of numbers when doubles or triples of a number are part of that set? Do the doubles count as two and the triples three, or does each count only as one toward determining the median.
Harley Wston lui répond.
Two circles inscribed in a rectangle 2002-02-27
Amina pose la question :
Given a rectangle with dimensions L=6, H=5. Two circles are inscribed such that they touch each other(circles are adjacent to each other) and also their circumferences touch 2 sides of the rectangle. One of the circles has radius=4. Find the radius of the other circle.
Penny Nom lui répond.
Simplify this expression 2002-02-26
Francine pose la question :
2X power 5 Y power 3 times 18 X power -5 Y power -3 divided by X power 1/3 Y power 1/4.

I came up with
     36 ---------- X 1/3 Y 1/4 
The book says 36 x1/3 y1/4.
I don't get it.

Penny Nom lui répond.
sin 2x = cos 3x 2002-02-25
Allan pose la question :
solve:

sin 2x = cos 3x

Primary question: how do you handle the cos 3x?


Paul Betts and Chris Fisher lui répond.
The substitution method 2002-02-24
Joe pose la question :
whats the answer to this question? 3x+y=11
x+2y=-3

its substitution method i am having alot of trouble figuring it out. send the answer as soon as possible. thank you


Penny Nom lui répond.
A hat of a different color 2002-02-24
Kirstin pose la question :
A teacher made a deal with 3 of his students. He said that if you can guess what color hat you have on your head without looking, I will pass you. There were 2 red hats and 3 blue hats. The deal worked like this: The three students would close there eyes, and the teacher would put a hat on each of their heads and then hide the other 2. Then one at a time, the students would open their eyes and try to figure out what color hat was on their head. The student could guess or pass. This is what happened when they put their deal to the test: A boy named Arturo was first and opened his eyes but wasn't sure so he passed so he didn't get it wrong. Belicia was next and she passed too because she wasn't sure. Also she thought about the fact that Arturo didn't know. Carletta was last and without even opening her eyes, she knew for sure what color hat she was wearing and her answer was right. So i have to figure out what color hat she's wearing for sure.
Claude Tardif lui répond.
350 students took the math A exam 2002-02-22
Jim pose la question :
at a high school 350 students took the math A exam. 82% passed the test. 40 students that failed the exam in june, took the exam in August. 70% of this group passed the August test. How many of the original 350 students have passed the exam before september?
Paul Betts and Penny Nom lui répond.
1,4,27,____,_____46656 2002-02-21
Brenda pose la question :
1,4,27,____,_____46656..... please find the fourth and fifth numbers in this sequence.
Penny Nom lui répond.
Alfredos house number 2002-02-21
Aunt Patty pose la question :
Alfredos house number is between 20 and 35. The sum of the digits is less than 5. If you subtract 1 from it you would get a multiple of 3. If you add three, you get a multiple of 5. What is Alfredos house number.
Penny Nom lui répond.
Proof by induction 2002-02-20
Tamaswati pose la question :
How do I prove the assertion that "the determinant of an upper triangular matrix is the product of the diagonal entries" by mathematical induction? (Before I check this assertion for a few values of n how do I rephrase the assertion slightly so that n appears explicitly in the assertion?)
Penny Nom lui répond.
An octagon-shaped deck 2002-02-20
An instructor pose la question :
How can you solve for finding the side measurements of an octagon-shaped deck that is 10 feet long and 10 feet wide.
Penny Nom lui répond.
When will the calendar be the same as 2002? 2002-02-20
John pose la question :
When will the calendar be the same as 2002? I know the answer is 2013, but I don't know how to answer this mathematically, or if it is possible to do so. This is a ninth grade level algebra question my daughter received from her teacher. Any ideas?
Chris Fisher, Patrick Maidorn and Penny Nom lui répond.
Shipping charges 2002-02-19
Sohail pose la question :
A mail order company charges a fixed fee for shipping merchandise that weighs 1 pound or less, plus an additional fee for each pound over 1 pound. If there shipping charge for 5 pounds is $4.80, and for 12 pounds is $6.20, find the fixed fee and the additional fee.
Penny Nom lui répond.
A farmer takes 100 animals to the market to sell. 2002-02-19
Ann pose la question :
A farmer takes 100 animals to the market to sell. All are sold and $100 is earned. The prices were $5.00 per cow, $1.00 per sheep and $.05 per pig. At least one of each kind of animal was sold. How many of each kind of animal did the farmer take to market?
Penny Nom lui répond.
Sampling distributions 2002-02-18
A student pose la question :
  1. given: n = 40, standard deviation is not known, population of individual observations not normal. does the central limit theorem apply in this case? why or why not?

  2. for an estimation problem, list two ways of reducing the magnitude of sampling error?

  3. What will happen to the magnitude of sampling error if the confidence level is raised all other things remaining the same? justify your answer?

Harley Weston lui répond.
Double square roots 2002-02-17
Ali pose la question :
i have a question about how to do double square roots with variables and powers.

example : v/"" v/"" 81y8


Harley Weston lui répond.
A degree 5 polynomial 2002-02-17
Carla pose la question :
Write an equation for a polynomial of degree 5 given the following zeros:
-7+3i, -2+sqrt(13), 6

Penny Nom lui répond.
Can the standard deviation ever = 0? 2002-02-16
Karen pose la question :
If given a class of 30 people who take a test with a mean of 80. Can the standard deviation ever = 0? If so, why?
Penny Nom lui répond.
Diameter of a pipe 2002-02-16
Landry pose la question :
I am trying to calculate the dia. of a pipe 60 inches long that will hold a gallon of water. What is the formula?
Penny Nom lui répond.
The perimeter of an ellipse 2002-02-14
Harry pose la question :
I am planning to build a coffe table with an ellipse of 24x36 for the top. I wish to decorate the edge and need to know the lenght of the perimeter for lay out purposes. Is there an easy way to approximate this figure with out using intergal calculus?
Penny Nom lui répond.
Nets for pyramids 2002-02-14
Michelle pose la question :
I want to have my students create nets for pyramids and I need to know how to find the correct range of degrees for the interior congruent angles of the isosceles triangular faces. For example, I know for a square-based pyramid that 77 degrees will work; however, I know other angle measures will also work. I'm just not sure how to find the minimum degree measure to have the net actually "work". I'm assuming the maximum would be 89 degrees, although that would make for a very tall pyramid.
Penny Nom lui répond.
36 is 20% less than _____? 2002-02-13
Lori pose la question :
36 is 20% less than _____?
Walter Whiteley lui répond.
A man and his wife walk up a moving escalator 2002-02-13
Monty pose la question :
A man and his wife walk up a moving escalator. The man walks twice as fast as his wife. When he arrives at the top, he has taken 28 steps. When she arrives at the top, she has taken 21 steps. How many steps are visible in the escalator at any one time.
Peeny Nom and Claude Tardif lui répond.
What is 20 to the thousandth power? 2002-02-12
Kristi pose la question :
What is 20 to the thousandth power?
Paul Betts lui répond.
Three bugs on a line 2002-02-12
Murray pose la question :
  1. Three bugs are crawling on the coordinate plane. They move one at a time, and each bug will only crawl in a direction parallel to the line joining the other two.
    • If the bugs start out at (0,0), (3,0), and (0,3), is it possible that after some time the first bug will end up back where it started, while the other two bugs switch places?
    • Can the three bugs end up at (1,2), (2,5), and (-2,3)?


    AND

  2. A single peg is placed at the bottom left-hand corner of a grid that extends infinitely far up and to the right. You play a game in which you are allowed to make the following move: if the hole immediately above and the hole immediately to the right of a peg are both empty, you can remove the existing peg and place pegs in those two holes instead.
    • Show that, no matter how you move, you can never remove all the pegs from the 3-by-3 square at the bottom left-hand corner of the grid. (b)
    • Is it possible to remove all the pegs from the six holes closest to the bottom left-hand corner of the grid (the region indicated in the picture below)?

Claude Tardif lui répond.
The slopes of the sides of the Great Pyramid 2002-02-09
Christina pose la question :
The Great Pyramid is the largest of the Egyptian pryamids. When it was built, it was 481 feet tall and had a square base with 755-foot sides. The pyramid has two different slopes-one along its sides and the other along its edges. Which slope is steeper?
Penny Nom lui répond.
The number of hidden cubes 2002-02-05
Katie pose la question :
This problem is about finding the number of cubes visible and hidden in a cube.

In a cube that is 3x3, 19 cubes can be seen. 8 are hidden.
In a cube that is 4x4, 37 cubes can be seen. 27 are hidden.
In a cube that is 5x5, 61 cubes can be seen. 64 are hidden.
In a cube that is 6x6, 91 cubes can be seen. 125 are hidden.

The question is:
Explain how you could find the number of small cubes that are visible and hidden in a cube of any size.


Paul Betts and Penny Nom lui répond.
Parabolas 2002-02-03
Kuang pose la question :
-Who is credited for working with or studying the Parabola?

-What is a conic section?

-What does a parabola look like?

-How is a parabola formed?

-Where and how are parabolas used today in the real world?


Harley Weston lui répond.
Number conversions and averages 2002-02-03
A student pose la question :
A table has the measurements of 1.6m by 2m, how much material is needed to cover table? I converted to cm then multiplied but got an answer of 32000cm ,so I divide by 100 to get to metres - the answer was 320 which I know is wrong - please explain!!

Also I need to explain in my own words what an 'average' is and I am struggling.


Penny Nom lui répond.
Square arrangements of clovers 2002-02-03
Cassie pose la question :
Clyde had a strange fascination with numbers. One day he decided to mount his 4 leaf clover collection in groups of square numbers.he took a long piece of butcher paper and glue and began this arduous task.There was 1 clover,4 clovers.and then 9 clovers in the third set. what would be in the seventh set of 4 leaf clovers?
Penny Nom lui répond.
Zeta[2]=(Pi2)/6 2002-02-02
alex pose la question :
Can you please tell me a proof that Zeta[2]=(Pi2)/6
Chris Fisher lui répond.
I am a fraction 2002-02-01
Anthony pose la question :
I am a fraction that is greater than 1 but less than 2. The sum of my numerator and denominator is 11. My denominator subtracted from my numerator is 1. What fraction am I?
Paul Betts lui répond.
The Euclidean Algorithm 2002-01-31
Murray pose la question :
Can you please explain to me why the euclidean algorithm works?
Penny Nom lui répond.
Baseball and sit ups 2002-01-31
A student pose la question :
A baseball team won 8 more games than it lost. If it played 56 games, how many games did it win?

On the first day of practice, Paul did 3 sit ups. On the second day he did 5, and on the the third day he did 8, and on the fourth day he did 12. If this pattern continued, how many sit-ups did ihe do on the sixth day of practice?


Penny Nom lui répond.
The size of a lot 2002-01-26
Claudia pose la question :
I own a piece of property that I need to know the square feet for assessment purposes. The figure they came up with is wrong. They measured from one point to another and halved the sums but that means I own the cul de sac and we don't. My lot is 55 feet wide and one side is 108.96 feet and the other side is 146.04 that extends all the way to a circle. The front of the lot on the cul de sac is stated on the survey like this. 78.21 feet where R=40 feet. This large arc is taken off the size of our land. How many square feet is our lot.
Harley Weston lui répond.
Logico mathematical knowledge 2002-01-23
A teacher pose la question :
How does young children's logico mathematical knowledge develop?
Walter Whitely lui répond.
Adding algebraic fractions 2002-01-23
Francine pose la question :

Hello, I've come up with an answer for the following problem but it's not the same as the book's answer. However, the book has a lot of mistakes in it and I don't know if I'm doing it properly or not. Your help would be soooo appreciated. It's driving me crazy.The problem is:

   
  2             + 3          + 4 
---------  +  ---------  +  ---------- 
(x-1)^3        (x-1)^2       (x-1) 

[(x-1)^3 is (x-1) to power of 3 etc.]


Penny Nom lui répond.
Some trig problems 2002-01-22
Grant pose la question :

Solve each problem for theta(there is no sign on my computer)for 0 is less than or equal to theta which is less less than 360

  1. 2cosx-1=0
    cosx=1/2
    Anwser 60,300

  2. tanx-2sinxtanx=0
    tanx(-2sin+1)=0 (factor ?)
    tanx=0 and sin= 1/2 (solve from there?)

  3. 2sinx-cscx=0
    2sinx-1/sinx=0
    3sinx-1=0
    3sinx=1/3(?)

  4. 4cos(2x)+2cosx= -1
    8cosx+2cosx+1=0
    10cosx+1=0
    10cosx= -1/10 (?)

  5. cos(2x-30)=1/2
    cos2x-cos30=1/2
    cos2x-cos30-1/2=0
    i don`t know what to do know

  6. Sinx+cosx=0
    Square both sides?

Claude Tardif lui répond.
Miles and kilometers 2002-01-22
Dennis pose la question :
I'm in the middle of purchasng a vehicle and it was built in Canada. Therefore it is in kilometers and not in miles. I forgot how many kilometers are in a mile. It registers as 183,049 kilometers.
Penny Nom and Judi McDonald lui répond.
Normal distribution 2002-01-21
Danielle pose la question :
A teacher gave a test on which the students' marks were normally distributed, but the results were pathetic. The mean was 52% and the standart deviation was 12%. The teacher decided that the top 10% of the students should get A's, the next 20% should get B's, the next 40% should get C's, the next 20% should get D's, and the bottom 10% should get F's. To the nearest percent, what are the cutoff marks that will result in an A, B, C, D, and F?
Penny Nom lui répond.
Successive differences 2002-01-20
Linsey pose la question :
what is the rule for working out the formula for a sequence with three lines of difference? eg.
                      
                     1, 3, 7, 15, 29 
1st line differences:  2, 4, 8, 14 
2nd line differences:    2, 4, 6 
3rd line differences:     2, 2 

Penny Nom lui répond.
Rolling 5 sevens before rolling a six or an eight 2002-01-20
Tony pose la question :
When rolling 2 dice, what is the probability of rolling 5 sevens before rolling a six or an eight?
Andrei Volodin and Penny Nom lui répond.
The distance across a circle 2002-01-18
Douglas pose la question :
If you know how far around a circle is (say earth) 25000 miles how do you calculate the distance across?
Penny Nom lui répond.
Making 24 2002-01-17
Renee pose la question :
My 4th grade daughter and I need to find a simple math sentence using 5, 5, 3, & 7 to equal 24. You can add, subtract, divide or multiple.
Penny Nom lui répond.
A sale on eggs 2002-01-17
A student pose la question :
A store had a sale on eggs, selling 13 eggs for the usual price of a dozen eggs. As a result, the price of the eggs was reduced by 4 cents a dozen. What is the original price for a dozen eggs?
Penny Nom lui répond.
My salary is doubled everyday for 30 days 2002-01-17
Kanishk pose la question :
I recieve 1 penny the 1st day, 2 pennies the 2nd day, and my salary is doubled everyday for 30 days. How much money will I have by the end of the 30 day time period? (Is there a way of solving this problem without a chart?)
Penny Nom lui répond.
A sequence 2002-01-16
Chris pose la question :
I have spent two days trying to determine the pattern to the following set of numbers: 1,4,9,1,6,2,5,3,6,4,9,6,4,8,1,____. I need the next four numbers to the sequence.
Claude Tardif lui répond.
Children and probability 2002-01-16
Bill pose la question :
If a family has four children, what is the probability that all 4 are the same sex?
Vanrei Volodin lui répond.
Negative exponents 2002-01-16
Julie pose la question :
If z to the power of -4= 1/z4 then how would you solve 1/t-2?
Penny Nom lui répond.
Linear regression 2002-01-16
Murray pose la question :
If you have a set of coordinates (x[1],y[1]),(x[2],y[2]),...,(x[n],y[n]),find the value of m and b for which SIGMA[from 1 to m=n]AbsoluteValue(y[m]-m*x[m]-b) is at its absolute minimum.
Harley Weston lui répond.
50% 2002-01-15
Lakarrieh pose la question :
4 is 50% of what number?
Penny Nom lui répond.
What is a group of three numbers called in a large number? 2002-01-15
Laurie pose la question :
What is a group of three numbers called in a large number?

My son has this question on his 4th grade worksheet. I've taught middle school math for 7 years and nver heard of it.


Paul Betts lui répond.
8% tax 2002-01-15
A student pose la question :
total price including tax is $13359.60
8% tax was paid
What is the dollar amount of tax paid?

Penny Nom lui répond.
Algebra review questions 2002-01-14
A student pose la question :
  1. A wildebeast was observed racing a distance of 86.4m in 4.8 seconds. Find the speed of the wildebeast in m/s.

  2. 8x - 7 - 5x = 23

  3. 7 z - 3 (z + 2) = 26

Penny Nom lui répond.
Adding vectors 2002-01-12
Lena pose la question :
how do you add vectors together?
If you are given the length and angles of both vectors and are asked to add/subtract them, how do you do it? I know you are supposed to do the head to tail method, but whenever i try it i get the wrong answer. I need help setting it up.

example: A is 2.7cm, and 60 degrees, B is 1.6cm and 135 degrees, find the magnitude and amplitude


Penny Nom lui répond.
The tangent function 2002-01-12
Justine pose la question :
if you know that sin45degress = cos45degrees, how do you know that tan45degrees = 1?
Penny Nom lui répond.
The famous "train problem" 2002-01-12
Karen pose la question :
How do you solve the famous "train problem"? For example, 2 trains leave different stations at the same time. One is traveling at 50 mph and the other at 40 mph. How long does it take them to meet?
Penny Nom lui répond.
Papy's Computer 2002-01-11
Mary-Anne pose la question :
My second-grade son brought home a fun math worksheet which involved calculating sums using "Papy's Computer." I had never heard of this before and found it to be quite interesting. Each digit in a decimal number is represented by a 2x2 grid. Each grid square corresponds to one of the numbers 1,2,4, or 8.
Harley Weston lui répond.
Why do integers have the symbol of Z? 2002-01-11
Stephanie pose la question :
Why do integers have the symbol of Z? Natural numbers have the symbol of N, whole numbers have the symbol of W. Our professor has asked us to find out why the letter Z is represented for integers.
Penny Nom lui répond.
A sequence of number pairs 2002-01-10
Terry pose la question :
Three is the first number of a pair, and 8 is the second.

a. If 50 is the first number, what is the second number?
b. If 200 is the first number, what is the second number?
c. If 89 is the second number, what is the first number?
d. If a number n is the first number, what is the second number?

3-8
4-11
5-14
6-17
____
____
____
10-29
____
____
____

Peny Nom lui répond.
Glasses of wine 2002-01-10
A student pose la question :

6 glasses of regular wine (12% alcohol) would equal aprox.? glasses of wine (8% alcohol)

a)9.33
b)8.5
c)7.75
d)9.0


Peny Nom lui répond.
A simplification problem 2002-01-10
A Parent pose la question :
FIND

(A / B) . (C / D)
where
A = Y squared + 3 . Y cubed
B = Y squared + 4
C = 2 . Y + Y squared
D = Y + 4 Y squared + 3 Y cubed


Penny Nom lui répond.
An octagon inscribed in a circle 2002-01-10
Kent pose la question :
A circle of 30 in. diameter has an octagon (8 equal chords) inscribed in it. What is the length of each chord?
Chris Fisher lui répond.
Nickles, dimes, quarters and fifty cent pieces 2002-01-08
A parent pose la question :
The total for all coins counted is $4,564.50 The last coin added to the pile is a 50 cent piece There are 8 times as many 50 cent pieces as there are quarters There are 6 times as many dimes as nickles How many of each are there?
Penny Nom lui répond.
All of the Christmas trees are fifty-five percent off. 2002-01-08
A teacher pose la question :
All of the Christmas trees are fifty-five percent off. Madison bought a tree and paid $103.50. Assuming no tax, what was the original price of the tree?
Penny Nom lui répond.
Maple trees and pine trees 2002-01-06
A student pose la question :
A team of scientists found that in a forest there was four maple trees for every nine pine trees.How many maple were there if they counted 45 more pine than maples?
Penny Nom lui répond.
Catenary 2002-01-02
Jason pose la question :
I am a high school math teacher. I was asked by a friend who is in architectural design for a method for determining the volume of what he called a Catenary.

The Catenary curve is modeled by the equation y=a cosh(x/a). I ran into a mess when I tried to compute the volume of the solid formed by revolving that curve around the y-axis.

Any help you can provide would be greatly appreciated.


Harley Weston lui répond.
Isoperimetric quotients 2002-01-02
A student pose la question :
I'm stuck on my GCSE Maths coursework, what do isoperimetric quotients measure?
Penny Nom lui répond.
2/3 vs 3/4 2002-01-02
Julia pose la question :
So, here's my question. Some of the problems they've had to do starts off with two fractions, and they have to tell whether the two fractions are:
  1. The first one is greater than the second one
  2. The first one is less than the second one, or
  3. They are equal.

One day my son had the problem of 2/3 vs 3/4. Without drawing out a pie chart, how in the world can a child "eyeball" a problem like this and tell what the correct answer is? I've also tried to teach about making common denominators, but that's going over his head at this point.


Denis Hanson and Harley Weston lui répond.
Fractions to decimals and percents 2001-12-31
A student pose la question :
2/5 , 4/8 , 4/10 , 3/5 , 6/8 , 7/7 (what is the decimal and percent for each)

1/5 , 1/10 , 1/8 , 1/1 (what is the decimal for each)

100 PERCENT, WHAT IS THE DECIMAL?

The ratio of boys to girls in a class is 1:4. What percent of the class are girls?

Penny Nom lui répond.
A hyperbola centered at (0,0) 2001-12-28
Carla pose la question :
  1. Find the equation of the hyperbola centered at (0,0) with vertices at (0,3) and (0,-3) that is asymptotic to the lines y=+-5x.

  2. Find the equation of a hyperbola in standard position foci (1,5) and (1,7) and eccentricity 2.

Peny Nom lui répond.
Two algebra problems 2001-12-24
Cass pose la question :
if the graph of a equation is 2x2 - y2 = 8 passes through point (6,k), find the positive value of k.

if 5x2 - 2 x = 1, find positive value of x


Penny Nom lui répond.
The probability that the area of a triangle is smaller that 1/8 2001-12-21
Hoda pose la question :
Given unit square pick two points on adjacent sides of the square , what is the probability that the area of the resulting triangle is smaller that 1/8? I tried to tackle the problem by first sketching a square with the four vertices at (0,0), (1,1), (0,1) and (1,1). The answer seems to be the area under the curve y=0.25/x between 1 and 0, but how can you integrate such a function when ln0 is undefined? any help would be highly appreciated.
Andrei Volodin lui répond.
Feeding Jumbo 2001-12-21
Lupe pose la question :
There are 2 dogs one named major and the other jumbo. major weighs 100 pounds and jumbo 150 pounds. they eat dry dog food which comes in a 40-pound bag that cost $30. Together, major and jumbo eat a whole bag a week. major eats two fifths of the bag while jumbo eats the rest.How much would it cost to feed jumbo in february, which has 28 days?
Penny Nom lui répond.
450 students 2001-12-19
Jessie pose la question :
My teacher told me that the number of ways of lining up the 450 students in our school is larger than the number of atoms in the universe. Is this right?

This question came to Good Question, a regular feature on the CBC Morning Edition radio show in Saskatchewan.


Denis Hanson and Harley Weston lui répond.
Getting to B in the shortest time 2001-12-19
Nancy pose la question :
A motorist in a desert 5 mi. from point A, which is the nearest point on a long, straight road, wishes to get to point B on the road. If the car can travel 15 mi/hr on the desert and 39 mi/hr on the road to get to B, in the shortest possible time if......

A.) B is 5 mi. from A

B.) B is 10 mi. from A

C.) B is 1 mi. from A


Penny Nom lui répond.
Simultaneous equations 2001-12-17
Matthew pose la question :
4x + y = 4
2x - 3y = 5

what is x and y


Penny Nom lui répond.
Making toys 2001-12-17
Karen pose la question :
Jonathan and Morgan are two of Santa's elves. Jonathan can make a toy in eleven hours. Morgan can make the same toy in nine hours. How long it take for both Jonathan and Morgan to make the toy if they were working together?
Claude Tardif lui répond.
Composition of functions 2001-12-16
Paula pose la question :
  1. if f(x)= 3x-1 and g(x)= 1/2x + 3 find fog(2)

  2. find the values of x for which tanx=0

Penny Nom lui répond.
A 1 m by 1 m square box in the xy-plane 2001-12-15
Murray pose la question :
Inside a 1 m by 1 m square box in the xy-plane, there are finitely many line segments, whose lengths sum to exactly 10 m. Show that there exists a straight line in the plane which crosses at least six of these line segments. (Hint: first, show that there exists a straight line in the plane which crosses at least five of these line segments.)
Claude Tardif lui répond.
A right-angled triangle 2001-12-13
Pamela, Jeff, Kayleigh and Jacob pose la question :
A right-angled triangle has one side that is 8 cm shorter that the hypotenuse. The other side is 1 cm shorter than the hypotenuse. Find the length of the sides.
Penny nom lui répond.
Algabra 2001-12-13
Stephanie pose la question :
My name is Stephanie. My grade 7 class is doing some strange form of algebra which I've never done nor seen before. We are doing equations like these: 3y - 6 + 7 - 4y = 6y - 6. I don't really understand them and was wondering if you could help me do my homework and explain how to at the same time. It would be really great if you could!!!!! Thank you so much! -Stephanie
  1. -9x - 5 - 8 + x = ?

  2. 5 + 6x - 3y + x + 8y = ?

  3. -x - 3 + 5x + 6y + 8x - 9= ?

Penny Nom lui répond.
Reduce 79,537/3,623,420 2001-12-13
Eliana pose la question :
How do you reduce 79,537/3,623,420.
Claude Tardif lui répond.
A 7% increase 2001-12-12
Lorraine pose la question :
how do you calculate an old salary if the only information you have is current salary and the percentage increase received. For example if I make $15.86 an hour and I received a 7% increase, how much did I used to make?
Penny Nom lui répond.
For 7 the multiplicand is 143 2001-12-12
Cory pose la question :
For 7 the multiplicand is 143

I am asked to solve this, if you could help me it would be greatly appreciated!


Penny Nom lui répond.
A quadrilateral with 0 sets of parallel sides 2001-12-12
Jess pose la question :
Ok well for quadrilaterals a parallelogram is a 4 sided figure with 2 sets of parallel sides and a trapezoid is a 4 sided figure with 1 set of parallel sides.

So is there a name for a quadrilateral with 0 sets of parallel side?


Chris Fisher lui répond.
Painting walls 2001-12-12
Rizwan pose la question :
3 sixth graders painted 4 walls in 3.5hrs. At that rate, how many walls would they paint in 7 hrs.
Penny Nom lui répond.
Recalling the basic facts 2001-12-12
A parent pose la question :
My son is in 4th grade and is a very bright student. He is in the gifted program and makes straight A's on his report card and has through out school so far. My question is how can I teach him to memorize his basic math facts? He does well in math, but when he is placed in a times situation for completing math fact sheets he freezes up. He can not recall the basic facts when questioned at any other time either. He will calculate the answer in his head, like 6 + 3, but he can't just come out with the answer quickly. How can I help him?
Claude Tardif lui répond.
Division symbol 2001-12-12
Amanda pose la question :
What is the name of the symbole used in a long divison problem that seperates the two factors? It looks like a little house.
Penny Nom lui répond.
Exponential form 2001-12-11
Crystal pose la question :
Hi, I am asking a question on behalf of a homeschooling grade 11 student. She is having trouble with changing something like (3-4)2 into a exponential form.

First of all she needs to know what the term means "exponential form" and then the process of it.


Penny Nom lui répond.
y = zx - x - c 2001-12-11
Andrew pose la question :
Could you please help me work out the value of x where: y = zx - x - c
Penny Nom lui répond.
Normal lines 2001-12-11
Kristie pose la question :
Why are perpendicular lines called normal lines?
Chris Fisher lui répond.
Cinderella clothes 2001-12-11
A student pose la question :
If cinderella clothes, inc. has determined that 0.5% of all incoming phone calls involve complaints, what is the probability that in 200 incoming calls there are more than one complaint?
Andrei Volodin lui répond.
y= (3x+2)/(4x-5) 2001-12-05
Courtney pose la question :
y= (3x+2)/(4x-5)
solve for x

Penny Nom lui répond.
Piles of coins 2001-12-05
A student pose la question :
Sharon has less than 20 coins. When she puts them in piles of 5, she has 1 left over. When she put them in piles of 3, she also has 1 left over. How many coins does Sharon have?
Penny Nom lui répond.
QED 2001-12-05
Derek pose la question :
What does Q.E.D. mean?
Harley Weston lui répond.
Fractions in lowest terms 2001-12-05
Thomas pose la question :
how to change decimal to a fraction in the lowest terms .7 .65 .019 .0111 .225 .1225 .625 .25 .025 .26 .875 .5 .75 .750 .33 .09 .44 .15 .12 .90 .044 .2500 .95 .500 .02 .40 .125 .1276 .00009 .45 .125 .1276 .375 .975 .054 .0005 .20 .2 .0001 .85 .80 .9 .0007 9.8 10.17 25.75 48.4 80.35 19.64 276.20 31.042 18.1034
Penny Nom lui répond.
Two equations in two unknowns 2001-12-04
Courtney pose la question :
y = 3x + 2
y = 4x - 5

solve for x

Penny Nom lui répond.
Permutations and combinations 2001-12-03
Linda pose la question :
There are 12 people who can be chosen for a project.

Q1. Suppose that 2 people refuse to work together. How many groups of 7 can be chosen to work on a project?

Q2. Suppose that 2 people insist on working together or neither will work on the project. How many groups of 7 can be chosen to work on the project?


Penny Nom lui répond.
83.3% 2001-12-03
Ellie pose la question :
Please explain how a percentage like 83.3% is changed into a fractions. The answer given is 5/6 and I changed 83.3% to a regular decimal of .833, which would be 833/1000. How do they get 5/6 from that? HELP
Chris Fisher lui répond.
Integers 2001-12-02
Alison pose la question :
How do you use integers in your everday life?
Harley Weston lui répond.
Solving x^2-3x+5=0 2001-11-30
Katy pose la question :
How do you find the solution to x2-3x+5=0?
Penny Nom lui répond.
Can a infinite set be smaller than another infinite set? 2001-11-29
Carlos pose la question :
Can a infinite set be smaller than another infinite set? If so why?
Chris Fisher and Penny Nom lui répond.
3, 6, 10, 15, 21 2001-11-29
Patrick pose la question :
we are trying to find the expression to solve for the nth term in the pattern

3, 6, 10, 15, 21


Denis Hanson lui répond.
A lighthouse and related rates 2001-11-29
Melissa pose la question :
A lighthouse is located on a small island 3 km away from the nearest point P on a straight shoreline, and its light makes 4 revolutions per minute. How fast is the beam of light moving along the shoreline when it is 1 km from P?
Penny Nom lui répond.
Multinomial theorem 2001-11-28
Murray pose la question :
Could you please state and explain the multinomial theorem (I already know the binomial theorem etc, to give you an idea of where i am)
Harley Weston lui répond.
Slope intercept form 2001-11-27
A student pose la question :
what is slope intercept form?
Penny Nom lui répond.
Numerical problems 2001-11-27
Yossi pose la question :
I am preparing a 45 minutes class for K-12 students. The problem is to show that algebraic equivalent expressions are not always numerically equivalent. In particular I would like to show one of these dangers: cancellation that occurs during the subtraction of nearly equal quantities. Do you have a good reference I could use to prepare my class. In particular to be able to show some examples and how one can avoid this type of error. I also would like to show examples with practical use. I tried to look up in the web but did not find anyhting appropriate.
Chris Fisher lui répond.
Original value 2001-11-27
Lisa pose la question :
We are trying to find the original value of a product marked up by 10%. What is the formula to determine the original value?
Penny Nom lui répond.
Dual spaces 2001-11-26
Hoda pose la question :
In the book "Linear Functional Analysis" from Epstein there is a proof (page 116) of the following theorem:

The dual space of Lp is equal to Lq.

Later, it is stated as a theorem without proof that

for 1 <= p < +infinite, The dual space of lp is equal to lq.


Doug Farenick lui répond.
Ratios and proportions 2001-11-26
Adam pose la question :
I am doing a project where I come to this website and ask a math expert about a certain topic. My topic is ratios and proportions. Can you please tell me what your job is and how you use ratio's and proportions in your job. Can you also please explain what ratios and proportions are.
Harley Weston lui répond.
A health club 2001-11-25
Maria pose la question :
A health club with a membership of 650 people operates a running track and an indoor swimming pool. A survey of the membership indicates that 68% use the running track, 44% use the swimming pool, and 8% use neither. If a member is chosen at random, what is the prbability that the member uses:

a) Both the track and the pool?

b) Only the track?


Penny Nom lui répond.
L'Hopital's Rule 2001-11-25
Mike pose la question :
I'm a high school senior. I'm in ap calculus and was wondering if you know the proof of L'Hopital's Rule? Our teacher said he has never been able to find it in a math book and was unable to derive it himself.
Claude Tardif lui répond.
Undetermined coefficients 2001-11-22
Hoda pose la question :
The equation is:

y" - 2y' + y = t et + 4

We need to use The method of Undetermined coefficients. I have tried assuming that the solution is Atet+Bet+C, but all I get is C=4 and I tried (At2+Bt+C)et+D, but again I get 0=0 when I calculate the first and second derivatives, so i get no information on the constants. Any suggestions?


Harley Weston lui répond.
Ratios 2001-11-21
Mike pose la question :
Simplify these ratios.

7 1/4 inches to 2 feet.

$0.02 per $1.75


Peny Nom lui répond.
Matrix 2001-11-21
Hoda pose la question :
I have a question about matrix multiplication; well, actually, matrix division. I am assuming that matrices are divided the same as they are multiplied; that is, row by column. But what happens if you have to divide by zero? How does this affect the resulting matrix?
Patrick Maidorn and Penny Nom lui répond.
A tangent line 2001-11-21
A student pose la question :
write an equation of the line tangent to the graph of

ey + ln(xy) = 1 + e at (e,1)

Harley Weston lui répond.
A hypercube 2001-11-20
Ace pose la question :
Can I get a picture of a hypercube
Patrick Maidorn lui répond.
Rewriting and evaluating formulas 2001-11-19
A conserned mother pose la question :
Due to the wide range of temperatures experienced in Canada, engineers who construct roads must allow for expansion and contraction of the road surface. The following formula is used to calculate the amount of expansion E to allow for: E= kL(T-t), where k is the constant of expansion for the road surface. L is the length of the section of highway in metres. T is the temperature of the air in degrees Celsius. t is the temperature, in degress Celsius, at which the section of the highway was constructed.
Walter Whiteley lui répond.
Cardinality of sets 2001-11-19
Tania pose la question :
  1. Show that the cardinality of P(X) (the power set of X) is equal to the cardinality of the set of all functions from X into {0,1}.

  2. Show that (the cardinality of the natural numbers set) |N| = |NxNxN|.

  3. Show that the cardinality of the set of prime numbers is the same as the cardinality of N+

Walter Whiteley lui répond.
Gallons 2001-11-19
Shawn pose la question :
Do we use British or American gallons in Canada?
Chris Fisher lui répond.
Translated by the vector (-5,2) 2001-11-19
Jennifer pose la question :
Give the image of (p,q) when translated by the vector (-5,2).
Penny Nom lui répond.
The "pi" of a circle in hyperbolic space 2001-11-19
Alex pose la question :
How can you find the "pi" of a circle in hyperbolic space (or is it the same). I would like to know because our environment is hyperbolic and if the "pi" of hyperbolic space is irrational, it would follow that space is non discrete. I would greatly appreciate any help in this question.
Walter Whiteley lui répond.
Box and Whisker plots 2001-11-19
Rod pose la question :
In our Prealgebra course, we have been studying Box and Whisker plots. Recently, we learned how to decide whether a data point is an outlier or not. The book (Math Thematics, McDougall Littell) gave a process by which we find the interquartile range, then multiply by 1.5. We add this number to the upper quartile, and any points above this are considered to be outliers. We also subtract the number from the lower quartile for the same effect.

My question: where does this 1.5 originate? Is this the standard for locating outliers, or can we choose any number (that seems reasonable, like 2 or 1.8 for example) to multiply with the Interquartile range? If it is a standard, were outliers simply defined via this process, or did statisticians use empirical evidence to suggest that 1.5 is somehow optimal for deciding whether data points are valid or not?


Penny Nom lui répond.
Renee, Paulo and Peter 2001-11-18
Sue pose la question :
Renee is 5 years older than Paulo. she is also 7 years older than Peter. The sum of their ages is 21. How old is each person.
Penny Nom lui répond.
Number sequences 2001-11-17
Stephanie pose la question :
My name is Stephanie. My grade 7 math class is studying number sequences and, to me, they make almost no sense at all. Here I wrote down 2 of the many problems I have for homework and was wondering if you could explain them to me (I have to find the next 3 numbers in each sequence.) It would be a big help!

10, 14, 18, 22, _, _, _.

12, 21, 39, 75, _, _, _.


Penny Nom lui répond.
A box of pants and shirts 2001-11-17
Debbie pose la question :
I need to determine the volume of a box that is 4'HX4'WX4'L. The box contains uniform pants and uniform shirts. I need to know how many shirts and pants are in the box. When folded, the uniform shirt is .5 inches thick. The pants are also .5 inches thick.
Penny Nom lui répond.
How do you get to 100 by using 6 nines? 2001-11-17
A student pose la question :
How do you get to 100 by using 6 nines?
Claude Tardif lui répond.
Magic squares 2001-11-17
A student pose la question :
7th grader wanting to find solution to magic square:

place the integers from -5 to +10 in the magic square so that the total of each row, column, and diagonal is 10. The magic square is 4 squares x 4 squares.

Penny Nom lui répond.
Some functions without numbers 2001-11-16
A student pose la question :
I have a worksheet that is about functions. It doesn't only use numbers. I need help to figure out the function and the solution to how the answer is solved.
Claude Tardif lui répond.
Numbering pages 2001-11-15
Lucy pose la question :
A printer uses 1008 digits to number the pages of a book. How many pages are there in the book?
Penny Nom lui répond.
Negative numbers 2001-11-15
Jewel pose la question :
If zero means nothing or an empty set, then how can a number be less than zero, as in negative number? My understanding of negative numbers is distance from a set point in a given direction. Thus having a negative and positive side of a line is arbritary and is related to displacement rather than value. Am I in error?
Penny Nom lui répond.
A clap of thunder 2001-11-15
Frustrated Mom pose la question :
While getting a recipe for the Thanksgiving feast. The teacher was talking on the phone with a friend who lives four miles north of her. She saw a flash of lightning through the window: fifteen seconds later, she heard a clap of thunder. Ten seconds after that she heard the thunder over the phone. Where did the lightning strike in relation to the teacher's house. (There are two possible answers. Sound travels about 1/5 mile per second. Some people say it's not good to be on the phone in a thunderstorm).
Claude Tardif and Penny Nom lui répond.
what number doubled plus 20 will give you 4/3 the original number 2001-11-15
Hank pose la question :
what number doubled plus 20 will give you 4/3 the original number

2 x__ + 20 = 4/3 of the original number

Penny Nom lui répond.
(a+b) squared and a squared plus b squared 2001-11-14
Kristen pose la question :

(a+b)2 = a2 + b2

Is this true for all whole numbers, and why?


Penny Nom lui répond.
Subsets of a countably infinite set 2001-11-14
Tania pose la question :
How could I show (and explain to my son) that any countably infinite set has uncontably many infinite subsets of which any two have only a finite number of elements in common?
Claude Tardif lui répond.
3x-1/2(x-4)+5= -3 2001-11-13
Tausa pose la question :
3x-1/2(x-4)+5= -3
Penny Nom lui répond.
Inequalities 2001-11-13
Pat pose la question :
When writing the solution to an inequality, why is the solution written in set notation? {x/ }
Penny Nom lui répond.
Prove that the medians of triangle PQR meet in a central point G. 2001-11-11
Jessica pose la question :
Use a scalene triancle with one point (0,b) on the y axis, another point (2c, 0) on the x-axis and the last point, (2a,0) on the x-axis. Prove that the medians of triangle PQR meet in a central point G.
Penny Nom lui répond.
A cubic 2001-11-10
Louise pose la question :
x3 + 9x2 - 7x - 63
Penny Nom lui répond.
1 minus 5(y) equals negative 2 2001-11-10
Judy pose la question :
1 minus 5(y) equals negative 2
Penny Nom lui répond.
A circle and triangle overlap 2001-11-09
Tara pose la question :
A circle and triangle overlap as shown.the area of the circle is three times the area of the triangle.If the common region is removed,then the area of the rest of the circle would be 14 sq cm more than the area of the rest of the triangle.How many sq cm are in the area of the complete triangle.
Penny Nom lui répond.
A circle and a triangle 2001-11-09
Tasha pose la question :
I have a circle that has an equalateral triangle inscribed in it. The tip of the triangle (B) is at the center of the circle with the other corners (A & C) extending to the sides of the circle. I need to know the equation to find the linear length of AC. I also need to find the cordial length of the circle from point C to A.
Penny Nom lui répond.
Third side of Acute Triangle 2001-11-09
Don pose la question :
I gave this problem to my children, 9th and 12th grade and they are not(me too!) sure of the answer. I am trying to determine the length of the third side of an acute triangle. I know two of the lengths but I do not know the angles. Is there a proper formula to use to find the length of the third side? Thank you.
Chris Fisher and Penny Nom lui répond.
12 pairs playing bridge 2001-11-09
Diana pose la question :
I have 12 pairs playing bridge against one another for 12 games. I need to have each pair partnered with another pair -- but only once. I'm looking for a schedule for play for all 12 games. They should only be able to play against another team only once also. (ex: 1/2 v 3/4 then 4/2 v 3/1) Thank you for this opportunity to solve my dilemma.
Claude Tardif lui répond.
Asymptotes 2001-11-09
Frank pose la question :

given the function:

f(x) = (x2) / (x-1)

the correct answer to the limit of f(x) as x approaches infinity is:

y = x+1

all math references point to this answer and the method they all use is long division of x-1 into x2

however if one were to multiply both the numerator and denominator by 1/x and then take the limit, one gets:

y=x

how can the descrepency between the two answers be explained?


Chris Fisher and Penny Nom lui répond.
A 3 dimensional 5 pointed star 2001-11-08
Kent pose la question :
I am looking for a formula that will give me a layout for a 3 dimensional 5 pointed star. I want to form it out of sheet metal, using 5 polygons and soldering them at the apex. Can you please help me with this? I would like to be able to give the formula the height of the star from the bottom two points to the top point and also how deep the star is. Thank you very much!
Judi McDonald lui répond.
Manufactures golf balls 2001-11-06
Kevin pose la question :
A company manufactures golf balls. Golf balls are each numbered consecutively 0 to 4, and then the numbering starts over with zero again. Every 12th golf ball is yellow. Every 8th golf ball is tested for defects. The company produces 120,000 golf balls in an eight-hour shift.

A. How many yellow golf balls are tested for defects during the day? Explain your reasoning.

B. How many of these yellow balls that are tested are imprinted with the numeral 2? Explain your reasoning.


Penny Nom lui répond.
Counting CD's 2001-11-06
Jason pose la question :
An older brother said to his younger brother, "Give me 8 of your CDs, then I will have twice as many as you." The younger brother replied, "No, you give me 8 of yours instead, and then we'll have an equal number." How many CDs does each boy have?
Chris Fisher lui répond.
2=the square root of (2 + the square root of (2 + the square root of (2 +...))) 2001-11-05
Cynthia pose la question :
justify algebreically, that:

2=the square root of 2 + the square root of 2 + the square root of 2 + the square root of 2 + the square root of 2 + and so on, .......


Penny Nom lui répond.
Squares of negative numbers 2001-11-03
Susana pose la question :
I wanted to know if I can square a negative number..?
Leeanne Boehm lui répond.
Applied geometry 2001-11-02
Jenny pose la question :
Where can I find some hands-on activities for my Applied Geometry classes? I want to do more activities with them that allow us to get out of the classroom. However, I want to use activities that use only inexpensive equipment because I usually buy the equipment myself.
Walter Whiteley lui répond.
A lighthouse problem 2001-11-02
A student pose la question :
A lighthouse at apoint P is 3 miles offshore from the nearest point O of a straight beach. A store is located 5 miles down the beach from O. The lighthouse keeper can row at 4 mph and walk at 3.25 mph.

a)How far doen the beach from O should the lighthouse keeper land in order to minimize the time from the lighthouse to the store?

b)What is the minimum rowing speed the makes it faster to row all the way?

Harley Weston lui répond.
15 % of 24.95 2001-11-01
Puzzled pose la question :
How do I take 15% of a number I have forgotten
Penny Nom lui répond.
8w-15 = 3w-10 2001-11-01
A student pose la question :
8w-15=3w-10, w =?????
Paul Betts lui répond.
Division by zero 2001-10-31
Stacy pose la question :
I have a question about dividing with zero. When the numerator is zero, the answer is zero. But when the denominator is zero, the answer is undefined. Why? I don't understand
Claude Tardif lui répond.
(-3)to the power 2, divided by 3 2001-10-31
Raz pose la question :
what is (-3)to the power 2, divided by 3=
Penny Nom lui répond.
m - 8 2001-10-30
Danita pose la question :
Can you please e-mail me the answer to m -8 for m = 20 and how you got the answer
Penny Nom lui répond.
3pi/2 - pi 2001-10-29
Karen pose la question :
I need to simplify this

a) 3pi/2 - pi


Penny Nom lui répond.
A sample size problem 2001-10-28
Charles pose la question :
The U.S Transportation Dept. will randomly sample traffic reports to estimate the proportion of accidents involving people over the age of 70. The Dept. has no advance estimate of this proportion. how many reports should the dept select to be atleast 97% confident that the estimate is within .01 of the true proportion?
Harley Weston lui répond.
Three problems 2001-10-28
Brenda pose la question :
  1. Joseph is planting bushes around the perimeter of his lawn. If the bushes must be planted 4 feet apart and Joseph's lawn is 64 feet wide and 124 feet long, how many bushes will Joseph need to purchase?

  2. The cost of a long distance phone call is $1.50 for the first two minutes and $0.60 for each additional minute. How much will Maria pay for a 24 minute phone call?

  3. Find the next three numbers in the pattern. 1,3,7,15,31,___,____,___.

Penny Nom lui répond.
Is the tree a pine tree? 2001-10-27
Kate pose la question :
Suppose Stock Brokers tell the truth 2/5 of the time, and 1/3 of the trees in a given forest are Pine. If 4 Stock Brokers say that a certain tree in that forest is Pine, what is the probability that the tree is indeed a Pine tree?
Penny Nom lui répond.
Negative times negative is positive 2001-10-26
Mary pose la question :
I have a question about adding and multiplying positive and negative numbers. When we add two negative numbers the answer is negative BUT when we multiply two negative numbers the answer is positive. I don't understand. Why?
Penny Nom lui répond.
Why do you flip the inequality sign? 2001-10-26
Sean pose la question :
I have a question about an inequality problem. Here it is: Solve and graph 5 - 3x => 17. (=> is greater than or equal). Please tell me why you flip the inequality sign when divinding by a negative number.
Penny Nom lui répond.
Concavity of f(g) 2001-10-25
Troy pose la question :
Suppose f & g are both concave upward on (-infinity,infinity). Under what condition on f will the composite function h(x)= f(g(x)) be concave upward?
Walter Whiteley lui répond.
An algebraic fraction 2001-10-25
brandi pose la question :
4x - 5
_____ =4
3-7x

Penny Nom lui répond.
Metric units 2001-10-25
Kelly pose la question :
i am helping my kids out with school work and don't remember meters,centimeters decimeters and all those. We have to change meters into cm.....and so on..........is there a place on the web to look for some kind of help in these questions
Penny Nom lui répond.
Where is the fourth point? 2001-10-24
Mike pose la question :
Four points are placed at random on a piece of paper. Connect the three points of the triangle of the largest area. What is the possibility that the fourth point is in the triangle?
Penny Nom lui répond.
A geometric series 2001-10-24
Tashalee pose la question :
The sum of the first 3 terms of a geometric series is 13. The sum of their reciprocal is 13/9. how do you find the first three terms?
Penny Nom lui répond.
Free pamphlets 2001-10-24
Salman pose la question :
a travel agency has limited number of six different free pamphlets about the beetle islands. the agent tells you to take any that you want, but not more than two of any kind. Assuming that you take at least one pamphlet, how many choices could you make
Penny Nom lui répond.
A right angled triangle 2001-10-23
Carissa pose la question :
How do you : Triangle ABC is right-angled at A. Calculate the length of the third side if b = 3 and c = 6, express the answer as a surd in its simplest form.
Harley Weston lui répond.
The distributive law 2001-10-23
Carissa pose la question :
How do you simplify the following using the distributive law :

5 squareroot 2+3 squareroot 2?

Penny Nom lui répond.
A $10,00 prize 2001-10-23
Michelle pose la question :
The grand prize for winning a contest is $10,000. After 28 percent of the prize is deducted for taxes, the winner receives the balance of the prize in annual payouts of equal amounts over a 3-year period. How many dollars will the prizewinner receive each year of the 3 years?(Disregard the $ sign when gridding your answer.)
Penny Nom lui répond.
Squaring the circle 2001-10-23
Margaret pose la question :
I have the following question that I cannot answer on my own (I don't know where to begin): Is it possible construct a square whose area will equal the area of a given circle? Please Explain why or why not.
Penny Nom lui répond.
The average of two polygons 2001-10-23
Irene pose la question :
How can I prove that the average of two polygons will give me another one?
Walter Whiteley lui répond.
Multiplying vectors 2001-10-22
Murray pose la question :
Could you please explain why a vector times a vector is a scalar and how to derive the formula vector a * vector b = ab cos(a,b)
Harley Weston lui répond.
Lines in the plane 2001-10-21
Greg pose la question :

*If the line with equation 3x-4ky= -16 has y-intercept -2, find k.

*Write the equation of the line passing through (2,5) and perpendicular to the line passing through (2,-4) and (6,1)


Penny Nom lui répond.
Water in a conical tank 2001-10-20
Sarah pose la question :
The problem: Water flows into a conical funnel at a continuous rate of one gallon per minute (One gallon = 231 Cu.In.). The height of the funnel is 5" and the diameter is 8".

The 1st formula: I need to develop a formula that will give the volume, in cubic inches, of the water in the funnel at any time t (in seconds). V = f(t).

The 2nd formula: I need to develop a formula that will give the height of the water in the funnel at any time t (in seconds). h = f(t).


Penny Nom lui répond.
Why quadratic for a second degree equation? 2001-10-20
Jana pose la question :
Why do we use the word quadratic to describe second degree equations?
Penny Nom lui répond.
A goat in a square pen 2001-10-19
Brad pose la question :
A goat is tied to one corner of a square pen 20 ft. on a side.
  1. If the goat's tether is 10 ft. long, what percentage of the grass in the pen can the goat reach?

  2. What should the length of the tether be so that the goat can reach half of the grass?

Penny Nom lui répond.
Symmetry of f(x) = ax^n 2001-10-18
Mohammed pose la question :
a function of the form f(x)=axn, where a doesn't equal 0 and n is a positive integer is called a power function . how is the exponent in the equation of a power function related to the symmetry of its graph?
Penny Nom lui répond.
414 is what percent of 5,624? 2001-10-18
A student pose la question :
414 is what percent of 5,624?
Penny Nom lui répond.
A function or not a function? 2001-10-18
Christian pose la question :
Which are the following are not functions?
  1. y = x2

  2. y = x3

  3. x = y2

  4. y = 3

Leeanne Boehm lui répond.
Tenths, hundredths, and thousandths 2001-10-17
Cheri pose la question :
I would like the French terms for the decimal place values of tenths, hundredths, and thousandths. (I would be interested in the Spanish terms also if you had them.)
Maria Torres and Claude Tardif lui répond.
Column doesn't add up to 100% 2001-10-17
A student pose la question :
why don't some tables I'm studying in a column add up to 100%? Example: N=338, but responses to questions asked in survey I'm studying equal of 24.3, 9.8, 43.8, DON'T add up to 100%. I'm assuming that some people surveyed out of the 338 didn't bother responding, but is there another problem related to proportion or ratio being used, but improperly labeled on graph?. Note at bottom of table says: "number in parenthesis are numbers of cases" and 338 was in parentheses. I'm lost.
Penny Nom lui répond.
A line in 3 dimensions 2001-10-17
Murray pose la question :
I'm working on a complicated proof and i need the equation for a line in 3 dimensions.
Claude Tardif lui répond.
Dividing a circle 2001-10-17
Ahmeen pose la question :
I am having a hard time figuring out how a circle can be divided into 11 equal parts with only 4 cut allowed? My teacher gave this to us and I still can't cut my pie into eleven equal parts with only four cuts.
Walter Whiteley lui répond.
Dimensions of a frame 2001-10-16
Rachel pose la question :
A rectangular picture frame has a perimiter of 44.2 cm.The width of the frame is seven tenths of its length what are the dimensions of the frame?
Penny Nom lui répond.
Proof by induction 2001-10-16
John pose la question :
Can you help me with any of these?
  1. For any natural number n > 1, prove that

    (4n) / (n + 1) < [(2n)!] / [(n!)2].

  2. For any natural number n > 1, prove that

    1/sqrt(1) + 1/sqrt(2) + 1/sqrt(3) + ... + 1/sqrt(n) > sqrt(n).

  3. For any natural number n and any x > 0, prove that

    xn + xn - 2 + xn - 4 + ... + x-n >= n + 1.

Penny Nom lui répond.
Some algebra 2001-10-15
James pose la question :
I cannot figure these out I was wondering if you could help me? I have no one to answer my questions.
  1. (7x2 – 3yz)2 – (7x2 + 3yz)2

  2. Use Pascal’s triangle to expand (2x – y)4

  3. 8x3 y - x3 y4

  4. (m + 3n)2 – 144

  5. 12x4 y – 16x3 y2 – 60x2 y3

  6. p3 q2 – 9p3 + 27q2 – 243

Peny Nom lui répond.
Squares of one digit numbers 2001-10-15
Needa pose la question :
What two two-digit numbers are each equal to their right-most digit squared?
Penny Nom lui répond.
Rules of exponents 2001-10-14
Carissa pose la question :
how do you work this out? Investigate the relationship between a,b,c and d if 2a*2b=4c/4d?
Leeanne Boehm lui répond.
Absolute Value 2001-10-14
Susan pose la question :
I am a homebound teacher, and my nineth grade algebra I student is having trouble understanding absolute value. Please send me an idea about how to best help her. She may be out of the classroom the entire year.
Chris Fisher lui répond.
Odd plus even is odd 2001-10-14
James pose la question :
Why is the sum of an odd number and an even number always odd?
Peny Nom lui répond.
Area of a quilt 2001-10-14
Jack pose la question :
  1. how would you find the area of the quilt? which is a square

  2. how would you fined the area of each square?

Penny Nom lui répond.
Theme day 2001-10-14
A teacher pose la question :
I woulld like a math theme for a theme day in a high school, grades 9-12. Our last theme was fractal fest.
Penny Nom and Claude Tardif lui répond.
Maximize the area 2001-10-13
Mike pose la question :

I have no clue how to do this problem. Here is what the professor gave to us:

A=LW

C=E(2L+2W) + I(PL)

Where P = # of partitions

E= cost of exterior of fence

I = cost of interior of fence

C = total cost of fence

.
.
.

Harley Weston lui répond.
Mathematical & conventional meaning of a word 2001-10-12
A student pose la question :
What is the mathematical & conventional meaning of a word? Like the word Rational or Median.
Penny Nom lui répond.
60 seconds in a minute 2001-10-11
Andy pose la question :
I am a fourth grade teacher. Yesterday my students asked "Why are there 60 seconds in a minute?" Which also led to 60 minutes in an hour? I have had trouble determining why the number 60? Any help would be appreciated.
Penny Nom lui répond.
4 sinx cosy = 1 2001-10-10
A student pose la question :
How would i differentiate the following example in terms of t (x and y are functions of t)

4 sinx cosy = 1


Claude Tardif lui répond.
Acres 2001-10-10
Allison pose la question :
how many feet are there in an acre?
Chris Fisher lui répond.
eix = cosx + isinx 2001-10-10
Peter pose la question :
Given: eix = cosx + isinx
  1. substitute -x for x to find e-ix, simplifying your answer

  2. use the given and part a to find an identity for cosx making no reference to trig functions

  3. find an identity for sinx
  4. .
  5. .

Penny Nom lui répond.
When will the ship disappear? 2001-10-10
Stacy pose la question :
If the sail of a ship were a 100 ft. tall and you were a mouse at the edge of the shore looking out at it, how far out would the ship be when it disappears? ( your eye level is level with the water.)
Harley Weston lui répond.
Ratio and proportion 2001-10-10
Steve pose la question :
Where would you use a proportion and/or a ratio in a real life job or problem.
Leeanne Boehm and Walter Whiteley lui répond.
Six nines 2001-10-09
A mom pose la question :
My middle schooler (sixth) has to calculate the integers 0-20 using only 6 nines. We have done all but the integer 14. He can not use decimals or double the nine like 99 or 19. the fraction 9/9 is okay. Keep in mind of course the order of operations.
Claude Tardif lui répond.
Pythagoras & magic squares 2001-10-09
John pose la question :
My grandson became intrigued when he recently 'did' Pythagoras at elementary school. He was particularly interested in the 3-4-5 triangle, and the fact that his teacher told him there was also a 5-12-13 triangle, i.e. both right-angled triangles with whole numbers for all three sides. He noticed that the shortest sides in the two triangles were consecutive odd numbers, 3 & 5, and he asked me if other right angled triangles existed, perhaps 'built' on 7, 9, 11 and so on.

I didn't know where to start on this, but, after trying all sorts of ideas, we discovered that the centre number in a 3-order 'magic square' was 5, i.e. (1+9)/2, and that 4 was 'one less'. Since the centre number in a 5-order 'magic square' was 13 and that 12 was 'one less' he reckoned that he should test whether a 7-order square would also generate a right-angled triangle for him. He found that 7-24-25, arrived at by the above process, also worked! He tried a few more at random, and they all worked. He then asked me two questions I can't begin to answer ...

  1. Is there a right-angled triangle whose sides are whole numbers for every triangle whose shortest side is a whole odd number? and

  2. Is each triangle unique (or, as he put it, can you only have one whole-number-sided right-angled triangle for each triangle whose shortest side is an odd number)?

Chris Fisher lui répond.
Lucas' theorem 2001-10-09
Tania pose la question :
How could I demonstrate: nCp is congruent to floor(n/p) (modulo p)? where rCk is a binomial coefficient, rCk = r(r-1)...(r-k+1)/k(k-1)...1, and p is a prime number
Richard McIntosh lui répond.
Binomial probabilities 2001-10-08
Amna pose la question :
I had a few binomial probability questions which I can not use from the tables as instructed:
  1. If 60 % of television viewers are watching a certain program, what is the probability tha tmore than half of those selected in a random sample of five will be watching the specified program?

  2. If it is known according to Mendel's Law, that we can expect in teh long run to have 3 white, 1 brown rabbits in every 4 rabbits of a certain type, what is the probability that 2 in a litter of 3 will be white?

  3. On the average, 2% of the items sold in a department store are returned for refunds. what is the probability that of its next five items sold, at most two will be returned for refunds?

Leeanne Boehm lui répond.
Mystery mathematician 2001-10-08
A student pose la question :
Theres a mathematician that was born on October 16 1879 in England and died on October 1 1921 in England. Suffered from severe disabilities. Did poorly in his degree and settled for a pass degree. Was awarded the Allen scholarship for research in 1904. He also applied logic to Physics in papers such as On Some Points in the Foundation of Mathematical Physics (1908). Who is it?
Claude Tardif lui répond.
15 mice in 4 cages 2001-10-08
Chelsea pose la question :
How can you fit 15 mice into 4 cages with an odd number of mice in each cage?
Claude Tardif and Harley Weston lui répond.
Finite differences 2001-10-08
Murray pose la question :
My name is Murray and I am a 10th grade student. Me and my friend have recently discovered and proved a theorem of a relitively advanced nature. It is that the the nth difference of an nth degree equation = n! times the coefficient of the highest power. One of my teachers said this theorem is part finite and that she thinks she has seen it before, but she does not remember what it is called, at what level it is taught, who discovered it or when it was invented. I would greatly appretiate answers to any of these questions.
Chris Fisher lui répond.
Locusts 2001-10-08
A parent pose la question :
JOHN CONJECTURED THAT BOTH 13-YR.&17-YR. LOCUSTS CAME OUT THE SAME YEAR. ASSUME IT IS CORRECT. HOW MANY YEARS PASS BETWEEN THE YRS. WHEN BOTH 13 YR. & 17YR. LOCUSTS ARE OUT AT THE SAME TIME? EXPLAIN. NEXT, SUPPOSE THERE WERE 12YR.,14 YR.,& 16YR. LO- CUSTS,& THEY ALL COME OUT THIS YR. HOW MANY YRS. WILL IT BE BEFORE THEY ALL COME OUT TOGETHER AGAIN?
Leeanne Boehm lui répond.
Simplify the expression 2001-10-08
Natalia pose la question :
simplify expression

4(x-7)+(-5x)=-10


Leeanne Boehm lui répond.
Percentage in our daily lives 2001-10-08
Natasha pose la question :
What are the uses of percentage in our daily lives?
Leeanne Boehm lui répond.
The amount of gravel needed to fill a hole 2001-10-06
Rhett pose la question :
My name is Rhett and my problem is...I am a contractor and I am having problems determining the amount of gravel(in tonnage) needed to fill this hole,the measurements are 60' in length,22' in width,and 14' in height....the problem is that it is not a usual box shaped hole or in this case a rectangle shaped hole,but more of a triangular shaped hole.I refer to the triangular shape as the interior shape of the crater not the exterior,which is shaped like the above dimensions.If you could help it would be greatly appreciated.P.s.This was a retaining wall project,built by myself, in front of a sloped end of a yard,so if you could imagine a 14" high hill with a landslide looking face,then build in your mind a three sided rectangle in front of it using the hill side that slopes as the fourth side of the rectangle,then you may be able to imagine what I mean as a triangular shaped interior of the hole.
Penny Nom lui répond.
Subtracting 5 from 25 2001-10-05
Melissa pose la question :
How many times can you subtract the number 5 from 25?
Leeanne Boehm lui répond.
A circle and a triangle 2001-10-04
Christina pose la question :
The points (3,4), (9.-2), and (-3,-2) define a circle and a triangle.
  1. find the areas of the circle and the triangle. Find the difference between their areas.

  2. Find the length of a side of a square with the same area as the triangle.

  3. Find the length of a side of a Square with the same are as the circle.

Penny Nom lui répond.
A Norman window 2001-10-04
Erin pose la question :
A Norman window has the shape of a rectangle surmounted by a semicircle. If the perimeter of the window is 30 ft, express the atrea, A, as a function of the width x of the window.
Penny Nom lui répond.
Zero as an exponent 2001-10-04
Wendy pose la question :
How do I explain to kids that i.e. 5 exponent 0 = 1?

Does 0 exponent 0 = 1?


Leeanne Boehm and Penny Nom lui répond.
Who owns what pet? 2001-10-03
A parent pose la question :
Don, Frank, Jenny, and Ken each come from one state, either Alaska, Maine, Montana, or Oklahoma. They each speak one primary language, either English, french, Russian, or Spanish. And they each have one of four pets, a chinchilla, a dog, a hamster, or a turtle.

Figure out which language and what pet each of the four people have, using the following clues.
.
.
.


Judi McDonald lui répond.
A polygon with five sides 2001-10-03
A student pose la question :
I was asked a question in 5th grade today that goes: i am a polygon with five sides and 2 right angles what do i look like and what is my name
Penny Nom lui répond.
The height of the lamppost 2001-10-02
Werner pose la question :
I am working on question 51,section 3.7 ,page 191 of Stewart's Single Variable Calculus. The question involves a lamp post which is casting a shadow around the eliipse whose formula is x2 + 4*y2 = 5. I have found the derivative of the elllipse both explicitly: x/4(((5-x2)/4)0.5) and implicitly : y' = - x/(4*y).
Harley Weston lui répond.
(x^2-5x-6)/(x-6) 2001-10-02
Bill pose la question :
given f(x) = (x2-5x-6)/(x-6) find f'(6).
Harley Weston lui répond.
Building numbers 2001-10-02
Dorothy pose la question :
Using only the numbers 1, 2. 3 & 4 and the order of operations make problems that have the answers of 1 to 50. Use each digit only once per problem. Use +, -, x, (), exponents or use 2 digits to form a 2 digit number Example 1,2=21 or 12. No Division.

We have been able to do all the problems except finding the answers of 7, 22, 31, 34, 42, 43 and 50.


Claude Tardif lui répond.
The median of a trapezoid 2001-10-01
Laura pose la question :
Given: A (1,2) B (9,-2) C (7,2) D (3,4)

Find the endpoints of the median. Use exact values. Write the equation using the letters from the given trapezoid. Verify the theorem using algebra.


Penny Nom lui répond.
1+2+3+...+1000 2001-10-01
Louise pose la question :
Find a quick way to add all Intergers (whole Numbers) between 1 and 1000?
Walter Whiteley lui répond.
Proof by induction 2001-09-30
Kyle pose la question :
I'm trying to learn induction and I need to see how this done please help with this problem...

20 + 21 + 22 +... + 2n = 2n+1 -1 is true whenever n is a positive integer.


Penny Nom lui répond.
Inverting a function 2001-09-30
Brandie pose la question :
Could you please tell me what is the basic guideline for inverting a function

Example:
S(R)=2PiRal
V(R)=PiR(squared)bl
R(V)=?


Claude Tardif lui répond.
The 100 chart 2001-09-28
Nich pose la question :
Am I suppose to use the 100 chart for these questions.

Question One:
I am a 2 digit number my tens digit is 2 more than my one digit my 1 digit is between 4 & 6. What # am I ?

Question Two:
I am a 2 digit # I am greater than 40 but less than 60 my tens and ones digits are the same I am a odd number what am I ?


Penny Nom lui répond.
Solitaire 2001-09-27
Babahadj pose la question :
Il s'agit du probleme du solitaire avec des cases numerotees 1, 2 et 3. Un pion se trouve initialement sur chacune des cases, sauf la centrale qui est vide. Au depart, il ya 15 pions sur les cases avec le numero 1 , 15 pions sur des cases avec le numero 2, et 14 pions sur des cases avec le numero 3. Le seul mouvement pour un pion P consiste a manger un pion P' en sautant par dessus ce dernier , a condition que le pion P' soit situe sur une case voisine (horizontalement / verticalement) et que la case dans laquelle aboutit le pion P soit vide. En partant de cet etat initial , est - il possible d'arriver a un etat final avec un seul pion se trouvant sur une case portant le numero 1. Pourquoi? Merci de me repondre.
      1 2 3       
      2 3 1       
      3 1 2 
1 2 3 1 2 3 1 2 3 
2 3 1 2 3 1 2 3 1 
3 1 2 3 1 2 3 1 2       
      1 2 3       
      2 3 1       
      3 1 2 

Claude Tardif lui répond.
1:5 2001-09-27
Sandy pose la question :
A colleague and I have a disagreement about dilutions. I seem to remember that I was taught (although it was a long time ago) that a RATIO was written thusly: 1:5 , and read " one part to five parts", for a total of 6 parts. On the other hand, a fraction is written: 1/5 and is read" one part in five" for a total of 5 parts. My colleague says that the ratio reads "one part in five" and is essentially the same as a fraction. Which is right? Have I been doing dilutions wrong all this time? I teach Animal Nursing and need to know where I can find a consise answer to such questions for making up medicated fluids, etc.
Penny Nom lui répond.
A bag with 3 red marbles and 2001-09-27
Mike pose la question :
In a bag, there are 3 red marbles and "B" blue marbles. Two marbles are randomly selected from the bag without replacement. The probability that the two marbles are the same color is 0.5. Calculate the sum of all possible values of B.
Claude Tardif lui répond.
The triangle inequality 2001-09-27
A student pose la question :
    
           __   __   __ 
Prove that AX + XB = AB for any X on AB.  

Chris fisher lui répond.
Find the pattern 2001-09-26
A parent pose la question :
MY SON HAD ON A WORKSHEET WHAT I HAVE LISTED BELOW, BUT WE CAN'T SEEM TO FIND THE PATTERN. MOST THE TIME WE CAN, BUT THIS ONE IS DIFFERENT.

6,___, 9,____,____,_____,_____,_____


Caude Tardif lui répond.
Joan and Jan work together 2001-09-26
Karyna pose la question :
Joan and Jan work together and they set up a bandstand in just 24 minutes, but if Joan does it by herself she takes 1 hour. How long would it take Jan to set up the bandstand by himself?
Claude Tardif lui répond.
Bicycles and tricycles 2001-09-26
Sally pose la question :
A bicycle shop has 5 bicycles and tricycles to repair. They have 12 wheels. What strategy would you use to determine how many bicycles and tricycles need to be repaired?
Claude Tardif, Diane Hanson and Penny Nom lui répond.
Scoring a college placement test 2001-09-26
Carmen pose la question :
A college placement test consist of 75 multiple-choice questions, each having 5 possible answers. The exam is scored by subtracting from the number of correct answers one-quarter of a point for each question answered incorrectly. If a person answers every question on the exam and scored 45, how many questions were answered wrong?
Penny Nom lui répond.
Investing in a yacht 2001-09-26
Junior pose la question :
Marvin and his four friends wish to invest in a yacht by sharing equally in the cost. As the date of sale approaches, Marvin realizes that if three more people join the partnership, each partner's share would decrease by $18,000. How much does the yacht cost?
Penny Nom lui répond.
Julia goes to work 2001-09-25
Karyna pose la question :
On one October morning, Julia rides her bike (at 12 miles per hour) from her home to her friend Ida's house; then the two of them walk (at 6 miles per hour) to work. If it takes an hour for Julia to go the 10 miles from her home to work, how far does she walk?
Penny Nom lui répond.
GCD and LCM 2001-09-24
David pose la question :
Find the GCD adn LCM of the following numbers. Assume p 2 to the power p, 3 to power q, 5 to power r

and

2 to power q, 3 to power r, 7 to power p


Penny Nom lui répond.
Four sequences 2001-09-24
Nicole pose la question :
I have a few questions I couldn't figure it out. So any help will be great to find the next three numbers or letters. Here's the patters...
  1. DEGHNORY, EHILMU, HIILMTU, BEILLMRUY,...

  2. 50, 33, 25, 20, 16, 14, 12,...

  3. 1777, 1795, 1818, 1819, 1820, 1822, 1836, 1837..

  4. A,H,I,M,O,T,...

Chris Fisher and Penny Nom lui répond.
What are the two numbers? 2001-09-24
A student pose la question :
What are the two numbers.
  1. the sum of two numbers is 15. 6 times the smaller number is 4 times the larger number .find the two numbers.
  2. the sum of the two numbers is 28. 2 times the larger number is 5 times the smaller number minus 7. find the two numbers.

Claude Tardif lui répond.
David's wages 2001-09-24
Kimberlee pose la question :
My math question is David earns $6.00 per hour plus $9.00 for every extra hour he works over 40 hours per week. If David earned $285.00 last week, how many extra hours did he work?
Penny Nom lui répond.
An acute scalene triangle 2001-09-24
Kim pose la question :
Hi- I'm on a mission--I'm suppose to have a group of children write up a hypotheses about the altitudes and angle biscetors of the follwing 3 types of triangle--equilateral, isosceles and acute scalene triangle.

Is there such a thing as a acute scalene triangle and why or why not.


Chris Fisher lui répond.
How much grass to mow? 2001-09-23
Jessica pose la question :

  1. The track and field area is 900 x 500 feet, including track and stands.
  2. The grass is mowed twice a week.
  3. 5,200 square feet of the sports area is not grass.

Problem: How many square feet of grass are mowed each week?


Penny Nom lui répond.
Ciefficient of variation 2001-09-23
Carmen pose la question :
I have a question from my OAC finite class. I've come across a problem with the coefficient of variation. I have taught my students that there are no units for coefficient of variation and it can be expressed as a percent. So, for example, a set of data with mean of 5 and standard deviation of 100 would have a CV of 5%. But what happens in this situation: the mean is 4meters and the standard deviation is 0.7mm. Is the CV 1.75% or 0.00175% or 0.0175%? I've had some students change leave the units as is, change them both to mm or change them both to meters...so which is it and why?
Penny Nom lui répond.
Solving trig equations 2001-09-22
Asad pose la question :
Can you please explain to me how to solve trig Equations,e.g sin(x)=x4+12/2+cos(x)=x6+9/3= (if this can be solved)
Claude Tardif lui répond.
What percent of the sports drink was drunk by the women? 2001-09-22
Rachel pose la question :
  1. The male track and field athletes drank 153 gallons of sports drink at the meet.
  2. the track and field athletes drank 255 gallons of sports drink.
  3. The women track and field athletes drank 102 gallons.

problem: What percent of the sports was drunk by the women?


Penny Nom lui répond.
4 digit combinations 2001-09-22
Laura pose la question :
I need all of the 4 digit combinations using the numbers 0-9.
Harley Weston lui répond.
Standard deviation 2001-09-22
Doug pose la question :
I was wondering if anybody knows who the founder of standard deviation was?
Penny Nom lui répond.
An egg shaped island 2001-09-22
Karen pose la question :
I am a civil engineering designer trying to design an egg shaped island. I want a 30' radius at the top and a 40' radius at the bottom and the longest length of the egg to be 125'. Is there standard geometry for an egg shape? I am not held to exact radii or the length given.
Chris Fisher lui répond.
Milliters and grams 2001-09-20
Betty-jo pose la question :
500 ml is what in grams
Pnny Nom lui répond.
The square root of 20 2001-09-18
Dianna pose la question :
How do you simplify a square root? My daughter tells me that the square root of 20 simplified is 5root4
Penny Nom lui répond.
Solve for h 2001-09-17
Kim pose la question :
s=2lw+2wh+2hl solve for h
Penny Nom lui répond.
4x(2x-1)+(2x-1)2 2001-09-17
Nick pose la question :
how do u solve 4x(2x-1)+(2x-1)2
Penny Nom lui répond.
A linear inequality 2001-09-17
Eric pose la question :
How can I solve |x + y| + |x - y|< =6?
Penny Nom lui répond.
Counterclockwise 2001-09-14
Rolanda pose la question :
When Descartes invented the coordinate system he decided to number them counter-clockwise. Why?
Chris Fisher lui répond.
300 pounds 2001-09-12
Cassie pose la question :
HOW MANY KILOS IS IN 300 POUNDS?
Penny Nom lui répond.
A polygon 2001-09-11
Sueling pose la question :
what is the smallest polygon. what is a polygon.
Penny Nom lui répond.
27 2001-09-10
Kacy pose la question :
In class we were given this problem. We have the numbers 30, 29, 19,11,26. these numbers = 27 in some way but how? the numbers can be applied any way using + - / X ( ) but can only be used 1 time each. can you please help me.
Claude Tardif lui répond.
Combien 1.0 ml fait en metre cube 2001-09-10
M. Mauger pose la question :
Bonjour, je voudrais savoir combien 1.0 ml fait en metre cube.
Claude Tardif lui répond.
Three fractions 2001-09-10
Kathleen pose la question :
a/bc + d/ef + g/hi = 1

Each of three fractions has a one-digit numerator and a two digit denominator. The three fractions together add up to one. Place the nine digits 1-9 into the fractions to make the equation correct.


Claude Tardif lui répond.
The square root of 21/168 2001-09-10
A student pose la question :
can you show me how to do this square root of 21/168
Penny Nom lui répond.
Rolling two dice 2001-09-10
Owen pose la question :
This probability question has been bugging me for a while. Two ordinary dice are rolled. If it is known that one shows a 5, what is the probability that they total 8?

I have two different but (seemingly) correct solutions.


Andrei Volodin lui répond.
Arithmetic sequences 2001-09-10
Rachel pose la question :
I can't seem to figure out a problem that deals with arithmetic sequencing. This is the question: The 5th term in an arithmetic sequence is 1/2, and the 20th term is 7/8. Find the first three terms of the sequence. I attempted this problem with the formula: An = a + (n-1)d (where the n represents the nth term, a is the first term, and d represents the common difference) I keep getting -9.5 for the first number, and then 3/120 as the common difference between the numbers. But as I have figured it, the sequence is getting greater and greater, and my data does not go with the terms given.
Penny Nom lui répond.
A 91-gon 2001-09-10
Ashley pose la question :
Hi! My name is Ashley and I am an 8th grader and I couldn't find the name of a polygon with 91 sides. i was a question from my math teacher.
Penny Nom lui répond.
Integers 2001-09-09
A student pose la question :
I am a Grade 9 student from Ontario Canada who has never understood how to do integers very well. I was wondering if you would be able to either send me some sites that will tell me how to calculate them in a simple way or if you would be able to write me back and give me some pointers.
Leeanne Boehm lui répond.
Double bar graphs 2001-09-09
Leslie pose la question :
My daughter has a homework problem in which she is graphing data from two frequency tables onto a double bar graph. The graph shows how many students worked in a program in two different years, grouped by age. In the first age group, one of the years has no students working, while there were students in that age group in the other year.
Penny Nom lui répond.
Similar triangles 2001-09-08
Dave pose la question :
I am standing on the bank of a river ( whose banks are parallel here) directly opposite a boathouse, B, on the opposite bank. I walk along the bank of the river past a signpost, S, until I reach a point C distant 60 metres from where I started walking. I then walk away from the bank, at right angles to the bank, until I reach a shady tree at D. Attached to teh tree is a sign stating that this spot is 45 metres from the signpost. C is 36 metres beyond S and B and S are in line from D.

(a) How far did I walk away from the bank of the river??

(b) Calculate the width of the river?


Penny Nom lui répond.
Multiplying binomials 2001-09-08
A student pose la question :
(x+1)(x+2)=?
(2x-1)(x-4)=0
please tell me this question!!

Leeanne Boehm lui répond.
The best of 7 2001-09-08
Michelle pose la question :
Professional basketball, hockey, and baseball championships are decided on the best 4 out of 7 games. The first team to win four games wins the championship. In how many possible ways could the team win the championship series after winning the first game?

 Example:  
Game   1    2    3    4    5     6     7         
Result W    L    L    W    W     W 

Leeanne Boehm lui répond.
Divisibility rules 2001-09-07
A student pose la question :
Why is it that when you add the digits of a number you can tell what the multiples of that number are. Example: 12131313111,

1+2+1+2+1+3+1+1+1=18,

therefore 12131313111 is divisble by 2, 9, 18, & 3 because those numbers are divisble by 18.

Penny Nom lui répond.
Don't worry too much about your difficulties in math... 2001-09-07
Matt pose la question :
Do you know who said,"Don't worry too much about your difficulties in math, I assure you that mine are still greater"? Thanks for your help. this for extra credit and I can't find it ANYWHERE!
Penny Nom lui répond.
0.999999=1? 2001-09-06
Catherine pose la question :
Hi! My teacher told us that 0.9 repeating equals one. We discussed how this is true. But, I was wondering if there is a proof that this is true. If so what is this called? I was trying to find information, but, it's hard when you don't know the name.
Walter Whiteley lui répond.
Commas in numbers 2001-09-06
Mike pose la question :
When did the Ontario Education system drop the use of commas in large numbers and replace with a space? Why?
Walter Whiteley lui répond.
Ray and Jane 2001-09-06
A student pose la question :
If Ray and Jane live 150 miles apart and they both leave their house at the same time, Ray goes 30 mph the whole time and Jane goes 50 mph the whole time how many miles are they from Ray's house when they meet? And what is the exact travel time untl they meet.
Penny Nom lui répond.
I have 6 digits. 2001-09-06
Kristan pose la question :
I have 6 digits. My hundred thousands is 1 less than my 1 digit, 8 greater than my thousands digit, twice my tens digit, and 4 times my hundreds digit. My ten thousands digit is 0. What # am I?
Penny Nom lui répond.
Sharing a donut 2001-09-06
Amanda pose la question :
You have invited 11 people over to your house one day, and your friends are hungry. You go into the kitchen and find out you only have 1 donut (with a hole in the middle). In order to feed 12 people (including you), you must cut the donut into 12 pieces with only using a straight knife and cutting 3 times. This is NOT a trick question.
Claude Tardif lui répond.
Earthquake warning 2001-09-03
Dillon pose la question :
In the city of Skangai there are 6 million people.Each person has to tell 2 more people that theres going to be an earthquake. After they do they leave the city. There will be no duplications.It takes 3 minutes to tell each person. How long will it take for the whole city to know about the earthquake?
Penny Nom lui répond.
72 cards 2001-09-03
A student pose la question :
What would be the probability of dealing a deck of 72 cards out in the exact orderly sequence that they were in when they were packaged after they have been throughly shuffled?
Andrei Volodin lui répond.
Two snakes 2001-08-31
A student pose la question :
Two snakes(pythons,actually)of same size and shape start swallowing each other by the tail with the same speed. What will happen ultimately?
Claude Tardif lui répond.
Joe and his dad 2001-08-28
Sarah pose la question :
Joe Spout left a campsite on a trip down the river in a canoe, traveling at 6 km/h. Four hours later, Joe's father set out after him in a motorboat. The motorboat traveled 30 km/h. How long after Joe`s father started did he overtake the canoe? How far had Joe traveled down the river when his father overtook him?
Leeanne Boehm lui répond.
Water jars 2001-08-27
Pe3te pose la question :
Stacie and Kacie each have a jar. Stacies jar holds 5 quarts of water and Kacies jar holds 3 quarts. The girls dad ask them to go get him some water from the pump and to get him 1 gallon of water (NO MORE NO LESS) The jars were not marked in any way. In ten minutes the girls where back with 1 gallon. How did they get exactly 1 gallon ?

1) there are two ways to do it I only no one. 1st answer is.....


Penny Nom lui répond.
Bisecting angles 2001-08-27
Monica pose la question :
Ray QS is the bisector for angle PQR. Find the measure of angle PQS and PQR if the measure of angle SQR is 52 degrees.
Penny Nom lui répond.
A sequence 2001-08-25
Sharon pose la question :
1
11
21
1211
111221
312211
1311221
1113213211
31131211131221
13211311123113112211

What would be the next sequence of numbers? my name is sharon i work in customer service and a friend asked me to solve this.


Walter Whiteley lui répond.
Vertices 2001-08-08
Jordan pose la question :
I am a fifth grader learning geometry with my mom's help, can you please explain what a vertices are??
Penny Nom lui répond.
Fourier transform 2001-08-07
Adbul pose la question :
  1. Sir, we have the Dirichlet's condition for the Fourier transform : " The function should be integral over the real line " But why we are we neglecting this for example when we take the Fourier transform of an impulse train?

  2. Suppose we want to travel from one corner of a square of side 'a' to the diagonally opposite corner. We can travel along the sides which gives a pah length of '2a'. We can also do it in steps as shown below:

      _ | |_PATH |   |_ |_____| 


    Suppose The step size =DELTA x Then the path length will be again '2a'. Now in the limit DELTA x -->0 again we get '2a' But when we take the limit we get the straight line diagonal whose length is 'SQRT(2)X a' Where did I go wrong?

Chris Fisher lui répond.
How far does the fly fly? 2001-08-07
Harold pose la question :
 
6 MPH                            4 MPH 
Rachel  ----------------------     Eli                        
                  10 Miles apart  

The fly is on Rachels handlebars. The fly is scared so it flys back and forth at 20 MP H. How far has the fly flown when Rachel and Eli meet?

f

Penny Nom lui répond.
Standard angles 2001-08-05
Nagaraj pose la question :
Why 0o , 30o , 45o , 60o ,and 90o are taken as standard angles in Trigonometry? Why can't we take some other angles as standard angles?
Chris Fisher lui répond.
Conformable matrices 2001-08-05
Wayne pose la question :
Can someone explain the concept of conformable matrices in a way that is easy to understand ? One definition says to multiply matrices rows and columns must conform, ie, 5 x 3 matrix times a 3 x 5 matrix. In the next example, however a 8 x 1 matrix and a 8 x 3 matrix are said to be conformable!
Steve Kirkland lui répond.
Linear regression 2001-08-01
A student and a mother pose la question :
My mom is taking a correspondence course in Simple Linear Regression and Correlation Analysis and we've been arguing about the relationship between the correlation -rxy and standard estimate of error-Sy.x. I took statistics last year in high school and I remember something about the Sy.x being proportionate to the r. Are they inversely related, directly related, not related, or can only range from 0 to 1.00? Her book doesn't say very much and I believe they are inversely related. She says they're directly related.
Chris Fisher and Penny Nom lui répond.
Intersection of perpendicular cylindrical surfaces 2001-07-31
Charlie pose la question :
Please consider two right circular cylinders, perpendicular one to the other, and of unlike radii in a 3 dimensional Cartesian space with mutually perpendicular x,y,z axes. If one cylinder is centered on the y axis with radius ra, and the other on the z axis with radius rb, then the expression for the first surface would be x2 + z2 = ra2, y = any number. Likewise, the second cylinder's surface would be x2 + y2 = rb2, z = any number.

It is my intent to define the curve at the intersection of these two cylindrical surfaces. From sketching the conditions it appears that this intersection resembles an ellipse folded about its minor axis.


Chris Fisher lui répond.
The radius of a planet 2001-07-30
Jessica pose la question :
A satellite is orbiting the earth at an altitude of 100 miles. If the angle of depression from the satellite to the horizon is 50 degrees, what is the radius (to the nearest mile) of the planet?
Harley Weston lui répond.
1996^1999 and 1999^1996 2001-07-29
Rajesh pose la question :
what is greater 19991997 or 19971999?
Chris Fisher lui répond.
The best linear model 2001-07-29
Rebeca pose la question :
I am a student (senior) summer hire working for Dept of the Army Resource Management. I've been assisting the Analyst in developing a model to predict training costs. The technique we used was simple linear regression. Now I've been asked for my opinion in choosing the best model I feel is better. I've chosen #1. Garrison Training but I want a second opinion before I give my choice. I've taken basic statistics last year in high school and will probably be taking more this year. Could you look over the information and give me a reason my choice would not be best? The dep variable-y, is Training costs in dolars per day.

ModelInd Variable- Xabrsy.x
1.Garrison Training126.310.9820.9055117.2
2.Local Training212.161.370.7937142.7
3.Man Rig Area116.382.470.6481175.6
4.Major Training346.124.670.7280167.2

Andrei Volodin lui répond.
e^pi > pi^e 2001-07-27
Dusty pose la question :
What book(s) contain a proof that ePi > Pie? I think it might be in Problems in Analysis published by Springer-Verlag but I have not been able to check.
Chris Fisher lui répond.
A trig identity 2001-07-27
Jeff pose la question :
prove this identity and show steps
tan(x/2+pi/4)=secx+tanx

Harley Weston lui répond.
Radian measure 2001-07-26
Amy pose la question :
i have to find out what is meant by the radian measure of an angle and compare it to the measure of an angle in degrees.
Harley Weston lui répond.
The Mean Value Theorem 2001-07-23
Corrie pose la question :
I need to find if the mean value theorem exists. and if so, find all values c guaranteed by the theorem.

f(x) = |x2-25| on the interval [-10,0]


Harley Weston lui répond.
What did the girls score on average? 2001-07-20
Rajesh pose la question :
The students of two schools were sitting the same test. The students attending the first school scored 74 on average; within this the average scores of the boys and the girls were 71 and 76, respectively. The corresponding scores in the other school were 84, 81 and 90, respectively. If the average score of all boys was 79, what did the girls score on average?
Penny Nom lui répond.
Matrix reconstruction 2001-07-19
Guy pose la question :
Is there a way to get the sums of rows, columns and diagonals of an n x n matrix to reconstruct the original matrix?
Walter Whiteley and Patrick Maidorn lui répond.
Hours worked 2001-07-18
Carlos pose la question :
I have a simple question:whats the formula to transform time into decimals? more exactly im working on a spreadsheet and i want to be able to type in for example hours worked: 11- 11:30 pm and a formula would tell me 12.5 hours how do i do it?
Patrick Maidorn lui répond.
Generating uniquie 2 digit numbers 2001-07-16
Anthony pose la question :
What methodology can I use to generate uniquie 2 digit numbers from unique 7 digit numbers. Of'course the total number of 7-digit numbers is not greater than 99.
Penny Nom lui répond.
Rhombus 2001-07-16
William pose la question :
Calculate the internal angles of a rhombus given measurments of all four sides only.
Walter Whiteley lui répond.
Margin of error 2001-07-13
Jim pose la question :
If a survey was completed by four different groups of people as indicated below what would the over-all margin of error be for this survey given the fact that the number of people in each group were different?
 
Group   # polled   Margin of error 
A.           779           +/- 4% 
B.           315           +/- 7% 
C.           323           +/- 6% 
D.           254           +/- 9% 

Andrei Volodin lui répond.
6,000,000,000,000,000,000 2001-07-12
James pose la question :
How would I express 6,000,000,000,000,000,000 in words?
Leeanne Boehm lui répond.
The speed of the boat 2001-07-12
Sharon pose la question :
A motor boat is travelling in a southeasterly direction in water that is flowing from the south at 2km per hour. Show that the speed of the boat is (6 times the square root of 2) km per hour, given that it can travel at 10km per hour in still water.
Penny Nom lui répond.
Comparing means and standard deviations 2001-07-11
Shelly pose la question :
Is there a way to compare means and standard deviations that come from different size samples? Is there an equation that can normalize sample size?
Andrei Volodin lui répond.
Investing $5,000 2001-07-09
A student pose la question :
A principal amount of $5,000 was invested in a savings account for 5 years.The interest earned was $500.Use the simple interest formula to find the annual rate of interest.
Penny Nom lui répond.
Cakes and ribbons 2001-07-05
Jennifer pose la question :
  1. A cake recipe calls for 3 1/4 cups of flour. You already put in 1 3/4 cups. How much more should you add?

  2. You have 3/4 yard of ribbon. How many 1/8-yard pieces can you cut the ribbon into?

Penny Nom lui répond.
Some irrational numbers 2001-07-03
Kellie pose la question :
  1. Is it possible to write pi as a fraction?

  2. Is it possible to write the square root of 2 as a fraction.. Explain why?

Harley Weston lui répond.
Arclength of an ellipse 2001-07-03
A hobbyist pose la question :
What is the equation (with the length of the arc as a variable) for one quadrant of the ellipse,...
Claude tardif lui répond.
A confidence interval 2001-06-28
Murray pose la question :
An investigator wants to find out of there are any difference in "skills" between full and part time students. Records show the following:
Student            Mean Score         Std Dev        Number
----------      -----------------     ----------     -----------
Full time              83                   12          45
Part time               70                   15          55
Compute a 95% confidence interval for the difference in mean scores.

Andrei Volodin lui répond.
Three chords 2001-06-28
Paul pose la question :
AE is a diameter of a circle and AC, CD and DE are chords of lengths 1, 2 and 3 respectively. (See the diagram.) Find the ridius of the circle.
Harley Weston lui répond.
Three tangents to a circle 2001-06-27
Stephanie pose la question :
The three lines PS, PT, and RQ are tangents to the circle. The points S, X, and T are the three points of tangency. Prove that the perimeter of triangle PQR is equal to 2PT.
Chris Fisher lui répond.
A three legged stool 2001-06-27
Teri pose la question :
I wanted to know why a three legged stool is always steady, and why a four legged stool is not. I am wanting to know the mathematical reasoning behind this.
Walter Whiteley lui répond.
A phone bill 2001-06-18
Janet pose la question :
What is the formuala to calculate cost per minute?

Here is the data below

# of calls - 238
# of minutes - 443
cost - $70.06


Penny Nom lui répond.
Two log problems 2001-06-16
A student pose la question :
Hi..this is one of 9th grade student in Fort Worth TX. well..I am doing EPGY stuffs in my school right now..and.. me and my teacher had problems to solve some advanced logarithmic thing. so I searched some sites to solve these two questions
  1. (log base 7 * 10) * (log base 10 * X ) = 2

  2. log base 10 * (3x-4) + log base 12 * X
    ---------------------------------------------------
    (log base 12 * 2) + (log base 12 * 5)

    = log base 10 *4

Harley Weston lui répond.
A calculation with 6 numbers 2001-06-16
Edwin pose la question :
I'm asked to come with, and program (in Ansi -C) an algorithm that calculates all the possible results of a calculation with 6 numbers and one result. For example: I want all calculations with the numbers 3, 3, 8, 8, 2, 9, and with a result of 786. all numbers may be used once, arithmetical operations allowed are + - / *, fractions are not allowed. The problem here is what is a fast method to do this (i.e. what's algorithm that can to this).
Claude Tardif lui répond.
A factoring problem 2001-06-14
A student pose la question :
What is the factoring of x squared -7+6 equal
Penny Nom lui répond.
Primes and square roots 2001-06-14
Paul pose la question :
I have a bit of a math problem. It has to do with determining if a very large number is a prime. One method entails dividing the number by every smaller prime number. If any divide into it, it's not a prime. This would be a big job if the number was something like 400 digits long. Another way I read about was to take the square root of the number and test all the primes less than its square root. The explanation went like this: "When a number is divided by another number that is greater than its square root, the result is a number smaller than the square root. For example, the square root of 36 is 6. Dividing 36 by 2, a smaller number than 6, gives 18, a number that is larger than the square root. To prove that 37 is prime it is only necessary to divide it by primes less than 6, since if it had a prime factor greater than 6, it would have to have one less than 6 as well."

I understand the explanation, up to the last sentence. I fail to see the underlying logic. Why if a prime factor exists below the square does one have to exist above the square too? The number 40 can be divided by the prime 2, a number below its square root, but no other primes can do this above its square root. Have I missed something? What's the logic here?


Claude Tardif and Penny Nom lui répond.
Euclid and Pythagoras 2001-06-14
Scott pose la question :
Question 1. In about 300 BC Euclid recorded a proof of Pythagoras rule. Disscuss Euclid's contribution to developing the theroem.

Question 2.

Why was it named after Pyhagoras if he did not orginally discover it?


Chris Fisher lui répond.
Area between curves 2001-06-13
Phil pose la question :

question 1

find the area bound by the curves y = x2 + 2x + 3 and y = 2x + 4

question 2

Find the volume generated by rotating the curve x2 + y2 = 9 about the x-axis

Harley Weston lui répond.
An inequality involving triangles 2001-06-12
Sandra pose la question :
The triangle inequality guarantees that the sum of the lengths of two sides of a triangle is greater than the length of the third. As a consequence, if x and y are legs of a right triangle, with x less than or equal to y, and z the hypotenuse, then x + y is greater than z, so x is greater than z - y. Under what circumstances will x is greater than 2(z - y) be true?
Chris Fisher and Penny Nom lui répond.
Monthly payments 2001-06-12
Anthony pose la question :
This question is base on my interest. I would like to know the formula for calculating this example: If you borrow $10,000 from a bank with an APR of 11.7% to be paid off in 5 years, what is your monthly payment?
Penny Nom lui répond.
5+5+5=550 2001-06-11
Tom pose la question :
I am in algebra and my teacher gave us an equation that was not true. she told us that we could only use one line segment(it can't bend turn has to be straight) to make the equation true. here is the equation: 5+5+5=550. i have not figured it out but have tried many things and believe it is not mathmatical but cross a # or sign out.also i forgot you can't put a slash mark through the equals sign.
Penny Nom lui répond.
Geometry problems involving triangles 2001-06-07
Sandi pose la question :
Find the radius of the largest circle contained in a right triangle whose legs are 8 and 15 and hypotenuse is 17. If the right triangle has legs a and b and hypotenuse c, find an expression for the radius of the circle.
Penny Nom lui répond.
Election in Angletown 2001-06-07
Zoe pose la question :
At the last school election in Angletown 4620 votes were cast. Candidate Acute received 236 more votes than Candidate Obtuse. Candidate Right received 698 votes more than Candidate Acute. Candidate Straight received 256 votes less than Candidate Right. How many votes did each receive?
Penny Nom lui répond.
Buying a car 2001-06-06
Steph pose la question :
How do you figure a percent. Say you want to buy a car listed for 21,500. You tell the dealer you want to pay 19,600. The dealer says they'll sell it to you for 20,450. how do you figure what the percent is between 20,450 & 19,600?
Penny Nom lui répond.
Danging couples 2001-06-06
Danielle pose la question :
How many boy-girl dancing couples could be formed if 85 boys and 102 girls attend a school dance?
Penny Nom lui répond.
Exponential form 2001-06-06
A student pose la question :
Hello can u please answer my question what is the exponent form of 8x8x8x8
Penny Nom lui répond.
Securing a plank in four dimensions 2001-06-06
Becca pose la question :
If it takes two nails to secure a plank from rotating on a wall in the third spatial dimension, how many nails would it take if you were attempting to secure the board from rotating in the fourth spatial dimension?
Walter Whiteley lui répond.
Mutually exclusive 2001-06-05
Marje pose la question :
What does the mathmatical term "mutually exclusive" mean. Pleas diagram if possible.
Penny Nom lui répond.
The shortest distance from a point to a line 2001-06-05
Kat pose la question :
Find the shortest distance from the given line. Round to the nearest tenth. (-2,-1) and x+5y+20=0
Penny Nom lui répond.
Where is the other $1? 2001-06-05
Samantha pose la question :
3 people go to a motel. The room is $30. They split it $10 each. While in the room the Mgr. tells the clerk the room was only $25, so he gives her $5 to take back to the 3 people. On the way she cant decide how to split the $5 between the three people so she puts $2 in her pocket and gives them $1 each.....Therefore, the room now only cost the three people $9 each, which is $27 plus the $2 the clerk pocketed,making a total of $29.....Where is the other $1?
Leeanne Boehm lui répond.
Two jugs 2001-06-04
Heather pose la question :
One goes to a source of water with two jugs and only two jugs. One jug had a capacity of exactly three pints and the other five pints. Both jugs are opaque (you canít see inside them) and irregularly shaped. How can you use the two jugs and only the two jugs to measure exactly four pints of water?
Harley Weston lui répond.
Conservation, consumption and population growth 2001-06-04
Steve pose la question :
I'm trying to quantify the relation between conservation/consumption and population growth. For instance let's consider California:

The 2000 census states that California's population grew from 29,760* in 4-1990 to 33,871 in 4-2000. I want to find r or rate of growth per year. Based on the exponential growth formula for population growth:
.
.
.


Penny Nom lui répond.
Common solution 2001-06-02
Samantha pose la question :
  1. Solve for common solution: x+y=6 2x-3y=2

  2. Solve for y in terms of x: 3x-y=4

Penny Nom lui répond.
Four digit numbers from 1,2,3,4,5,6,7,8 2001-05-31
Katie pose la question :
Okay.......here's my question...how many different ways can you form a four digit number out of these digits..1,2,3,4,5,6,7,8? This is how my teacher said to do this.... 8*8, 7*7,6*6,5*5,4*4,3*3,2*2,1*1. then she said to add up the products and to multiply by 7. is this correct, and if not how can you figure this out.
Penny Nom and Claude Tardif lui répond.
Chickens and sheep 2001-05-31
Monica pose la question :
Farmer Bob of the Martian Colony counted his sheep and chickens in an unusual way. When he finished, he reported that he had counted 86 feet and 26 heads. Use a guess and check table to find how many sheep and chickens are owned by the famer.
Paul Betts and Penny Nom lui répond.
Three goldfish 2001-05-30
Nathan pose la question :
A man has three goldfish. When the youngest goldfish was born, the oldest fish was three times the middle fish's age. Nine years ago the oldest fish's age was the sum of the two other fish's ages. How old are the three goldfish?
Penny Nom lui répond.
Multiplication 2001-05-30
Lindsay pose la question :
Who came up with multipling? its so easy
Claude Tardif and Penny Nom lui répond.
Your DJ Business 2001-05-30
Linda pose la question :
Your DJ Business has 6 rap, 10 rock, 6 alternative, 8 oldies, and 5 country CD singles. How many different 10-song sets can the DJ play, if she plays 2 singles from each category? and How many different 10-song sets if she plays exactly 3 rap singles and 4 rock singles in each set?
Leeanne Boehm lui répond.
Jim's poker game 2001-05-24
Nick and Karnal pose la question :
One day jim played poker with some of his friends and lost half his money.the number of dollars he had before the game was the same as the number of cents he had after the game, and the no of cents he had before the game was twice as much as the number of dollars he had after the game.how much money did he have before thegame???

Later that day jim met a friend Al on the street."hi al!Do u have any change on you al?""yes"
"Good!can u give me a change of a dollar?" "I am afraid not!"
"Then give me change of 50 cents.""I am sorry i cant."
"how about a change of a quarter?""not possible."
"a dime."
"also not"
"a nickel?"
"not even that."

al had no bills or silver dollars on him.whats the largest amount of cash he could have had? hope u can help me.

Penny Nom lui répond.
Pi 2001-05-24
Mary pose la question :
Where does the term pi come from and how many digits are actually in pi?
Penny Nom lui répond.
New Quebec reform 2001-05-24
Marie-Andrée pose la question :
I am a middle school teacher beginning to adapt to the new Quebec reform. I am regularely doing projects in écologie and géographie in French immersion based on the international schools way of thinking (What form does it have? How does it work? What is its history? How does it change? How is it linking to our lives? What is our responsibility about that fact or that thing?) and I have real difficulty to make it work for math. So now, I am looking for math concepts (8) which would link to the same way of thinking. What are your suggestions?
Claude Tardif lui répond.
SPRT 2001-05-24
A researcher pose la question :
I have a medical-pharmaceutical study that says:

SPRT (something to do with Secuential and Truncated).

Do You know what it means S.P.R.T. and what it is?


Ejaz Ahmed and Penny Nom lui répond.
The diameter of an oval 2001-05-23
Tim pose la question :
Is there a such thing as a diameter of a oval? If not, is there a way to get the circumference?
Claude Tardif and Penny Nom lui répond.
Harmonic numbers 2001-05-23
Leslie pose la question :
The harmonic numbers Hk, k = 1,2,3.....are defined by Hk = 1 + 1/2 + 1/3....1/k

I am trying to prove by mathematical induction:

H2n >= 1 + n/2 , whenever n is a nonnegative integer.

H8 = H23 >= 1 + 3/2

Can you help?


Harley Weston lui répond.
How many sides does a circle have? 2001-05-16
Georganne pose la question :
How many sides does a circle have?
My son answered "infinate" on a test and was corrected. The school insists the answer is 0.

Chris Fisher and Denis Hanson lui répond.
A 6 character field 2001-05-16
A parent pose la question :
I have a 6 character field that can use any combination of alpha-numeric characters (A-Z, 0-9). How many total combinations are possible?
Penny Nom lui répond.
Quadratics 2001-05-16
John pose la question :
I am in the final stages of a math project and I need to interview an expert for the last part. Please try to answer at least a few of these questions.
  1. How do you use quadratic equations in your everyday life?
  2. Do you find being a math expert very helpful in life?
  3. Is the quadratic equation useful to you?
  4. Why did you decide to become a math expert?
  5. What do you think is the most important function of the quadratic equation?

Harley Weston lui répond.
25 y^2 + 20 y z - 4 z^2 2001-05-15
Kimmy pose la question :
i don't know how to factor the trinomial 25y2 + 20yz - 4z2. I can get it, but i get messed up on getting the minus 4 at the end. all i get is a plus 4. Can it even be factored.
Penny Nom lui répond.
A pile of sand 2001-05-14
Gul pose la question :
  1. Sand for use on icy roads is stored in a conical pile 14.2 m high and with a base diameter of 34.4 m
    • calculate the volume of the pile

    • if one sander can take 6.9 m of sand, how many sanders can be filled from the pile?

Penny Nom lui répond.
A triangular pyramid 2001-05-14
Kumar pose la question :
In a Pyramid OABC, all the three sides of the base: a, b, c are known. Also known are the angles between the three sides from the vertex O: Angles AOB, BOC, COA.

With this information, is it possible to calculate the lengths of the three sides: OA, OB & OC.
Chris Fisher lui répond.

Manifolds 2001-05-14
Thierry pose la question :
Maybe you could help me, because I have serious problems for the translations of an English mathematic word which is "MANIFOLD". It's impossible to have a clear translation in French. Do you have a solution?
Claude Tardif lui répond.
Toy bricks 2001-05-13
Sarah pose la question :
A regular-sized brick weighs 4 kilograms. How much will a similar toy brick, made of the same material, but all of the same dimensions of which are four times smaller, weigh?

The 300-metre tall Eiffel tower is made of steel and weighs 8 000 000 kg. An exact replica, made of the same material, weighs 1 kg. How high is the replica


Penny Nom lui répond.
Simplifying algebraic expressions 2001-05-12
A student pose la question :
How do you simplify algebra expressions?
Penny Nom lui répond.
The height of a pyramid 2001-05-11
Ryan pose la question :
Jane is building a model of a pyramid for a history project. It has a square base of side length 100 cm. The angle of elevation of the sides is 60 degrees. What is the height of Jane's pyramid.
Harley Weston lui répond.
The angles in a triangle 2001-05-11
Nikki pose la question :
Find the measure, to the nearest degree, of each angle of a triangle with sides of the given lengths.

26, 35, 40


Penny Nom lui répond.
A quadratic function 2001-05-10
A parent pose la question :
A quadratic function is given by f:x------ax2+b

If the two points A(2, 2) and B (0, -8) are on the graph of the function, then find a and b.

Penny Nom lui répond.
Greatest Common Factor 2001-05-09
Nicole pose la question :
What is the Greatest Common Facter for:

126,261
1008,1080
546,1995
128,256
and
255,256

Penny Nom lui répond.
Circles, ellipses, parabolas and hyperbolas 2001-05-09
Colleen pose la question :
How is an ellipse like a circle?
In what way does an ellipse have a center?
How is a hyperbola similar and different to an ellipse?
How is a parabola similar a different to a circle ellipse and parabola?

Pnny Nom lui répond.
Marginal Propensity to Consume 2001-05-09
Esther pose la question :
The derivative of the national consumption function C = f(y) is called the ____________________.
Judi McDonald lui répond.
National consumption function 2001-05-09
Brian pose la question :
If consumption is $11 billion when disposable income is 0 and the marginal propensity to consume is dC/dy = 1/(2y+4)1/2+0.3(in billions of dollars), find the national consumption function.
Harley Weston lui répond.
Maximize profit 2001-05-09
Brian pose la question :
The marginal cost for a certain product is given by MC = 6x+60 and the fixed costs are $100. The marginal revenue is given by MR = 180-2x. Find the level of production that will maximize profit and find the profit or loss at that level.
Harley Weston lui répond.
Dividing fractions 2001-05-09
Rina pose la question :
I just wanted to ask if you could help me in math. See I'm having a test soon and its on Dividing Fractions and I just don't get it. My math teacher says that I'll be just fine but I failed my math quiz. I went to ask eric but they could help me so they told me to go to you. So here I am asking you if you could help me.
Penny Nom lui répond.
The area between two curves 2001-05-08
Esther pose la question :
Find the area of the region enclosed by the graphs of y = x3-6x and y = -2x between their points of intersection.
Harley Weston lui répond.
The average value of a continuous function 2001-05-08
Esther pose la question :
The average value of a continuous function y = f(x) on the interval [a,b] is given by ________________?
Harley Weston lui répond.
Neither prime nor composite 2001-05-08
Marc pose la question :
what 2 numbers are neither prime nor combitative?
Penny Nom lui répond.
Teaching square roots 2001-05-08
Katie pose la question :
My friend and I are doing a project. We have to teach our class about square roots. What is the easiest way to teach square roots to a class?
Penny Nom lui répond.
24 from 2, 2, 14, and 21 2001-05-08
Kimberly pose la question :
using the numbers 2, 2, 14, and 21. how can you get 24 using + - X or division
Claude Tardif lui répond.
Taking matches 2001-05-05
Mark pose la question :
Two piles of matches are on a table. A player can remove a match from either pile or a match from both piles. The player who takes the last match loses. If there are two players, how should you play?
Claude Tardif lui répond.
Probabilities and dice. 2001-05-04
Carmen pose la question :
Hi! My name is Carmen! I am a member of a grade 5 class in Edmonton, AB. We were talking about probability in math, and I was wanted to know what the probability (odds) of rolling two sixes would be rolling two dice? If it is not to diffucult could you tell me what the probability (odds) of rolling any number with two dice were?
Andrei Volodin and Penny Nom lui répond.
How many acres are in a square mile? 2001-05-04
Terri pose la question :
How many acres are in a square mile?
Judi McDonald lui répond.
Adding and subtracting rational expressions 2001-05-03
Donna pose la question :
Adding and subtracting Rational expressions. I am in grade 10 and I am a student here is an example of the questions:

1/(x+1) - 1/(x-1) = ?


Penny Nom lui répond.
Are you overweight? 2001-05-03
Oneita pose la question :
How do I square a number.....?

My problem is : square your height in inches and take 4.25 percent of the result to determine if you are overweight.


Claude Tardif lui répond.
Logs for the fire 2001-05-02
Tom pose la question :
Three girls named Amanda, Beatrice, and Cleo visit a summer cottage. Amanda brings 5 logs for the fire, Beatrice brings 3 logs and Cleo contributes 80 cents. How should the money be divided among the other two girls so that each of the three is felt to have contributed equally to the cost of the fire.
Penny Nom lui répond.
Graphing equations 2001-05-01
A student pose la question :
If, for example, 4x2-12x+9=0 and -4x2+12x-9=0, which I'm assuming it does since you can derive that equation from the first, why do those two equations have different graphs?
Penny Nom lui répond.
Tiling a floor 2001-05-01
Sarah pose la question :
Cut out of paper or cardboard a quadrilateral having no two sides parallel, no two sides of equal length and no indentations. Can an endless floor be tiled with copies of such a figure?
Claude Tardif lui répond.
Area of a regular polygon 2001-05-01
Carl pose la question :
What is the formula for finding the area of a regular Hexagon and a regular Pentagon
Penny Nom lui répond.
Population growth 2001-05-01
Gina pose la question :
Suppose the population of a country increases at a steady rate of 3% a year. If the population is 50 million at a certain time, what will it be 25 years later? Define the recurrence relation that solves this problem.
Penny Nom lui répond.
Average speed 2001-05-01
Tom pose la question :
A ship goes in one direction, west to Hawaii, at 20 nautical miles per hour and, because of the wind, makes the return trip at 30 nautical miles per hour. What is the average speed?
Claude Tardif lui répond.
Typing a project 2001-05-01
Tom pose la question :
Two students have to type a project. One can do it in 2 hours. It would take the other student three hours. They have 2 type writers. How fast can they finish by working simultaneously?
Claude Tardif lui répond.
A sequence defined recursively 2001-05-01
A student pose la question :
A sequence s is defined recursively as follows:

s0=1
s1=2
sk=2sk-2 for all integers

- Compute s2,s3,s4... to guess an explicit formula for the sequence sk.
Penny Nom lui répond.

A sequence of even terms 2001-04-29
A student pose la question :
A sequence c is defined recursively as follows:

c0 = 2
c1 = 4
c2 = 6

ck= 5ck-3 for all integers

Prove that cn is even for all integers.


Leeanne Boehm and Penny Nom lui répond.
Dominos 2001-04-28
Mark pose la question :
A standard dominoe set consists of 28 pieces, from double-zero to double-six

  1. Is it possible to arrange all those pieces in a straight line in such a way that the dots of any pair of adjacent pieces match? Please include picture

  2. Is it possible to arrange them in a circle and still meet the conditions in 1?


Claude Tardif lui répond.
Choosing a car 2001-04-28
Ashley pose la question :
THE CAR DEALERSHIP IN TOWN OFFERS 32 DIFFERENT MODELS OF VIHICLES.EACH MODEL HAS A CHOICE OF EIGHT INTERIOR COLORS,EIGHT EXTERIOR COLORS,AND ALSO THE OPTION OF AUTOMATIC OR MANUAL TRANSMISSION. HOW MANY COMBINATIONS ARE POSSIBLE?
Penny Nom and Andrei Volodin lui répond.
A Taylor series 2001-04-27
Karan pose la question :
Given the following information of the function
  1. f''(x) = 2f(x) for every value of x

  2. f(0) = 1

  3. f(0) = 0
what is the complete Taylor series for f(x) at a = 0

Harley Weston lui répond.
Triangles and fractions 2001-04-27
Constance pose la question :
My name is Constance and I am thirteen years old (I am a student). The question that I am queering about I don't understand why you do ONE HALF x the base x the width WHEN YOU WANT TO FIND the area of a triangle? My second question is if you multiply one half and 10 together why does it come out as 5?
Penny Nom lui répond.
Lots of coins 2001-04-26
A student pose la question :
I purchase 2 million coins at 9.75
I purchase 1 milion coins at 8
what is the formula to calculate my average cost?

Penny Nom lui répond.
A confidence interval 2001-04-26
Kim pose la question :
A poll asked 1528 adults if they were in favor of the death penalty, 1238 said yes, find 99% confidence level for percent of all adult who are in favor of the death penalty.
Andrei Volodin lui répond.
How many 6 digit numeral combinations 2001-04-26
Bryan pose la question :
How many 6 digit numeral combinations are there If you can only use 6 digits (1, 2, 3, 4, 5, 6) and no number can be used twice in the Numeral!
Claude Tardif lui répond.
Working together 2001-04-26
Stephanie pose la question :
Tom takes 10 hours to piant a mural on the wall of Evergreen School. Carol takes 6 hours to do the same job. If they work together, how long will it take them to paint the mural?
Claude Tardif and Penny Nom lui répond.
Tonya in the orange grove 2001-04-25
A parent pose la question :
Tonya was helping in the orange grove. She decided to take some oranges home to share with 3 friends. She gave 3 more than half to Jennifer. Angela got half the remainder and 3 more. She gave Josie half the remainder plus three. When she got home, she had only 10 oranges left. How many did she have when she left the grove?
Penny Nom lui répond.
A lemon and a recall 2001-04-25
Katie pose la question :
A Man has two cars, a recall and a lemon. The probability that the recall starts is 10%. The proabability that the lemon will start is 5%.

What is the proabability that both cars will start?


Andrei Volodin lui répond.
Expected value 2001-04-24
Cindy pose la question :
A game consists of rolling a single fair die. If a number great than 4 is rolled you win the number of dollars showing on the die. If any other number is rolled, you receive $1.00. What is the expected value of this game?
Andrei Volodin lui répond.
Squares of Fibonacci numbers 2001-04-24
Vandan pose la question :
What discoveries can be made about the sum of squares of Fibonacci's Sequence?
Penny Nom lui répond.
Writing in the math curriculum 2001-04-23
Wendy pose la question :
I am trying to incorporate more writing into my math curriculum. I am currently using journals and activities which involve written explanations. Any new ideas on how to involve my students more in the writing process in math class?
Walter Whiteley lui répond.
A few problems 2001-04-22
Carol pose la question :
Hello I am a College student trying get through my elmentry concepts class. I am also working with the middle and elementry school student with their work. I was given a few problems to work on and i am having a hard time explaining them to students. DO you think you can help with a coupld of these questions!
Penny Nom lui répond.
Oil revenue 2001-04-21
Brian pose la question :
Suppose that t months from now an oil well will be producing crude oil at the rate of r(t), not a constant, barrels per month and that the price of crude oil will be p(t), not a constant, dollars per barrel. Assume that the oil is sold as soon as it is extracted from the ground.
  1. Find an expression for the total revenue from the oil well, R(t).

  2. A certain oil well that currently yields 400 barrels of crude oil a month will run dry in 2 years. The price of crude oil is currently $18 per barrel and is expected to rise at a constant rate of 3 cents per barrel per month. What will be the total revenue from this well? {Hint: Model the degraded production rate with the equation:
    r(t) = (A-Bt)e0.04t}

Harley Weston lui répond.
Five 2001-04-21
Billie pose la question :
If One is single, two is twin, three is triple, four is quadruple, five is ????? what is five and where would I find the rest of the numbers,six, seven, eight, nine, etc.
Penny Nom lui répond.
Repeating decimals 2001-04-21
Sarah pose la question :
Hi, I'm working on a project for school. The theory I choose was "When turned into a fraction, a repeating decimal has a denometor that is a multiple of three." I have a couple of questions about this topic. My first question is, have you ever heard of this, and what can you tell me about it? My second question is, when I was testing this theory I came across .999... now, when this is a fraction it is 9/9 which is equal to one. The denometor is a multiple of 3, but it's a whole number. I don't understand how a decimal can be equal to a whole number since a decimal is a piece of a whole number. Please don't just show me a math problem, I don't want to see a math problem. I want to see an explanation of this theory and the decimal .999...
Penny Nom lui répond.
Geometry 2001-04-21
Rebecca pose la question :
How do you prove the following:
Let CD be an altitude of triangle ABC and assume that angle C=90 degrees. Let r1 and r2 be the inradii of triangle CAD and CBD, respectively, and show that r+r1+r2=CD, where r is the inradius of triangle ABC.

Chris Fisher lui répond.
Two boats 2001-04-19
Pat pose la question :
Two boats head directly toward each other, one of them traveling 12 miles per hour and the other traveling 17 miles per hour. They begin at a distance of 20 miles from each other. How far apart are they one minute before they collide?
Penny Nom lui répond.
Pyramids 2001-04-18
Kelly pose la question :
I'm in tenth grade and I know that there's some formula for finding out the slope of the side of a pyramid. I thought it could be the pythagorean therom, but I'm not sure if this works. Please send me the formula as soon as possible, I need it for a project.
Penny Nom lui répond.
A geometry proof 2001-04-18
Melissa pose la question :
Extend the bisectors of angle A, angle B, and angle C of triangle ABC to meet the circumcircle at points X, Y, and Z respectively. Show that I is the orthocenter of triangle XYZ.
Chris Fisher lui répond.
The number of occurrences of 0 is __, of 1 is __, of... 2001-04-17
Martyanne pose la question :
"In this sentence the number of occurrences of 0 is __, of 1 is __, of 2 is __, of 3 is __, of 4 is __, of 5 is __, of 6 is __, if 7 is __, of 8 is __, of 9 is __."

Each blank is to be filled with a numeral of one or more digits, written in decimal notation.

Claude Tardif lui répond.
Isoscles and scalene 2001-04-17
Autumn pose la question :
explain where the term isoscles and scalene came from?
Chris Fisher lui répond.
Differentiation 2001-04-17
Esther pose la question :
Could you please tell me what the first derivative is of the following:

y = 2/(2x+e2x)

Is it (1+xe2x)/(2x+e2x)2 or perhaps -4(1+e2x)/(2x+e2x)2 ? I am a little confused between the two!


Harley Weston lui répond.
Solving some equations 2001-04-16
Justin pose la question :
Solve the following equations for x
  1. x+7=10
    x=

  2. x-7=10
    x=

  3. 3x=7
    x=

  4. x/3=10
    x=

  5. .

  6. .

  7. .

  8. .

Penny Nom lui répond.
Leukemia 2001-04-15
Don pose la question :
Assume: Leukemia occurs at an incidence of 1 in 10,000.

Benzene is a known carcinogen which causes Leukemia and has been found in toxic levels in the homes of a community of 1200 people.

Question: How many cases of Leukemia would be necessary to reject the null hypothesis. That is, to suggest that statistically, the cases are more likely due to benzene exposure rather than chance.


Chris Fisher and Penny Nom lui répond.
Constructing an equilateral triangle 2001-04-14
Peggy pose la question :
Please send directions to make an equilateral triangle in plane geometry. I want each student to draw two, cut them out, and place them together to form a Jewish Star.
Penny Nom lui répond.
The sides of an octagon 2001-04-13
Craig pose la question :
How do I figure the length of the sides of an octagon when all I know is the diameter (4.375).
Penny Nom lui répond.
1 = 0.999... 2001-04-13
Joan pose la question :
I have a middle grade math question for you. I would like to know why .9999... = 1 ? I can not use algebra to show this or the following: We agree that 2 = 2 and that 2-2 = 0, so

1.00000......
-0.99999.....
----------------
0.000000......
and
0.000... = 0 therefore 0.9 = 1
----------OR--------------- 1/3 = 0.333333 and 3 X 1/3 = 1, so if 3 X 0.333... = 0.999... then 0.999... = 1

My teacher says that I can not use the above example to show why this is true, and that I must use a couple different examples. He says that there are several other ways. Do you know any? I could really use the help because I can't think of any other ways to show this is true. Thanks for any help you can give.


Penny Nom lui répond.
Squares on a chess board 2001-04-11
Tom pose la question :
It was once claimed that there are 204 squares on an ordinary chessboard (8sq. x 8sq.) Can you justify this claim? "PLEASE" include pictures.

How many rectangles are there on an ordinary chessboard? (8sq. x 8sq.) "PLEASE" include pictures.


Penny Nom lui répond.
Compound interest 2001-04-11
A student pose la question :
What principal will grow to $1367.10 after 1 year at 10% compounded semi-annually?
Claude Tardif and Penny Nom lui répond.
Prisms 2001-04-10
A fourth grade class pose la question :
A fourth grade class is curious about the names that have been given to various solid geometric figures based on their shapes: are there names for solids based on a rhombus, a trapezoid, a parallelogram, a decagon, and/or a quadralateral?
Chris Fisher lui répond.
Parabola problems 2001-04-10
Kathleen pose la question :
  1. Graph each function and state its domain and range. y = 3x2 + 4

  2. For each parabola find: i) the direction of opening
    ii) the coordinates of the vertex
    iii) the y-intercept
    iv) the x-intercepts
    y = x2 + 3

  3. Find the equation of each parabola vertex at (0, -2) and passing through the point (3,7)

Harley Weston lui répond.
Integration by parts 2001-04-09
A student pose la question :
how do you integrate x tan-1x dx, i know it can be done by integration by parts maybe, but i'm not sure....
Claude Tardif and Harley Weston lui répond.
The domain of a function 2001-04-08
Mina pose la question :
Let f(x) = (2x2+3x-17)/(x+5)
What is the domain of f? What are the values of x for which f'(x) does not = 0?

Harley Weston lui répond.
The normal to a curve 2001-04-08
Varenne pose la question :
I am having SO much trouble tackling this question and don't know what the right answer is... can you help me out? The question is

Find the equation of the normal to the curve y=(x-2)2/(1-x)2 that is parallel to the line x+4y+7=0

Harley Weston lui répond.
Five fourths 2001-04-08
Linda pose la question :
Can you have 5/4 of something?
Penny Nom lui répond.
Equivalent fractions 2001-04-08
A student pose la question :
which of the following pairs of fractions are equivalent?
questions a-f

(a) 1/5 and 6/30
(b) 4/9 and 16/27
(c) 6/10 and 30/50
(d) 15/20 and 48/64
(e) 2/3 and 33/100
(f) 12/32 and 3/16


please show how u got the answer thank you.

Penny Nom lui répond.
Common tangents 2001-04-08
Anne pose la question :
I have been working on this problem for a while but I'm not sure I'm getting the right answer: Find the common tangents of 2y=x2 and 2y=-x2-16 Thanks for the help. :)
Harley Weston` lui répond.
Where do the lines y=2x-4 and y=x-1 intesect? 2001-04-06
Bryce pose la question :
solve the following problem by setting them equal to each other. Solve for x and y. Where do the lines y=2x-4 and y=x-1 intesect?
Penny Nom lui répond.
The unit circle and trigonometry 2001-04-05
Ashley pose la question :
"My teacher wants us to find out what a unit circle is, which I found out, a circle with the radius of 1, but the problem is he wants us to show the relationship between the unit circle and the sine(30,45,60 degrees), cosine(30,45,60 degrees),and tangent ratios(30,45,60 degrees). I need help with this and my teacher will not help us out. Thanks very much ...
Penny Nom lui répond.
Hexominos 2001-04-05
Tom pose la question :
What is a hexomino and how many different shapes are possible?
Harley Weston lui répond.
A combination lock 2001-04-05
Ken pose la question :
What is total number of combinations possible on a combination lock which contains 3 wheels each numbered 0-9?
Penny Nom lui répond.
Percents 2001-04-04
Cathy pose la question :
This isvery embarassing but since math and specifically percentages was my worst subject in school here goes. If I have a figure such as 425 and that amount represents 10% of the total amount how do I find out what the total amount is?
Penny Nom lui répond.
f(x), f(x) + 2, f(x +2) 2001-04-04
Monica pose la question :
Could you explain to me how one should go about graphing functions such as f(x), f(x+2), and so on. Also, how should you explain things such as constants and relationships among functions?
Penny Nom lui répond.
128 percent too high 2001-04-04
A student pose la question :
when pilgrims counted noses, they got a count that was 128 percent too high. if they counted 9120 noses, what was the correct count?
Claude tardif lui répond.
Two integrals 2001-04-03
Jim pose la question :
I'm having trouble with these integrals. Can you help me out?

1)the integral of:

x5 arctan x dx

2)the integral of:

2x5 + 9x4 + 19x3 + 13x2 - 5x - 25
----------------------------------------------- dx
x4 + 4x3 + 5x2


Claude Tardif lui répond.
Approximating 260 divided by 3 2001-04-02
Andrew pose la question :
Choose the letter of the best estimate.

260 divided by 3

a. 60
b. 70
c. 90
d. 100


Paul Betts lui répond.
(8 + 5)5 = (y + 4)4 2001-04-01
Kelley pose la question :
(8 + 5)5 = (y + 4)4
What is the value of y?

Penny Nom lui répond.
Sigma 2001-03-31
A student pose la question :
What does the Sigma symbol mean in mathematics?
Penny Nom lui répond.
Volume and surface area of a cylinder and a triangular prism 2001-03-31
Kevin pose la question :
I was wondering how do you find the volume and surface area of a cylinder and a triangular prism.
Penny Nom lui répond.
Why K? 2001-03-30
Molly pose la question :
I was wondering why K is used as the dilation constant for transformation geometry?
Chris Fisher lui répond.
Dots on squared paper 2001-03-30
Tom pose la question :
Consider some squared paper with lines 1cm. apart and dots where the lines cross. Place squares whose sides are whole numbers of centimetres on the paper in such a way that the sides of the squares always lie along the lines on the paper. For each square, find (a)the number of points inside the squares; (b)the number of points on the square and (c)the area of the square. How are these quantities related?
Leeanne Boehm and Penny Nom lui répond.
Borrowing from zero 2001-03-30
Nikki pose la question :
Here is the problem:

5,033.56
- 866.20

Now I know this equals 4,167.36 which I figured out on the calculator just to make sure. But when I did it by hand, I kept ending up with 5,167.36, which I knew was impossible. What am I doing wrong??


Leeanne Boehm and Claude Tardif lui répond.
Stem-and-leaf plot 2001-03-29
Kelly pose la question :
I'm tutoring my 5th grade nephew, and he needs to correct test questions regarding a stem - and - leaf plot. He left his book at school and I'm not familiar with the term. Can you explain it to me so that I can help him?
Penny Nom lui répond.
An emergency response station 2001-03-29
Tara pose la question :
Three cities lying on a straight line want to jointly build an emergency response station. The distance between each town and the station should be as short as possible, so it cannot be built on the line itself, but somewhere east or west. Also, the larger the population of a city, the greater the need to place the station closer to that city. You are to minimize the overall sum of the products of the populations of each city and the square of the distance between that city and the facility. City A is 6 miles from the road's origin, City B is 19 miles away from the origin, and City C is 47 miles from the origin. The populations are 18,000 for City A, 13,000 for City B, and 11,000 for City C. Where should the station be located?
Claude Tardif and Penny Nom lui répond.
Cash advance 2001-03-28
A student pose la question :
dulani has a new credit card. it says: you can get cash advances wherever you are. whenever you want. also if you pay off your balance in full each month for a small transaction fee, the cash is interest free. (see important information on reverse side. On reverese side it says:

cash advance transaction fee:

$500 or less 2.5%;
$500.01 to $1000.00-2%;
$1000.01 or more -1.5%;
$2.00 minumum.

Annual percentage rater for cash advances 19.8%.
dulani wants to know what a cash advance will really cost. Analyze the cash advance terms given here. how much would he pay for a $20 cash advance? What about a $450 cash advance? What annual interest rate are these charges equivalent to? choose other amounts. determine cost and annual ratees for these as well. make recommendations to dulani.

Penny Nom lui répond.
The diagonal 2001-03-28
Candace pose la question :
Building measuring 40 feet 3 inches by 50 feet 3inches What is the measurement of the diagonal of the building? What was method of obtainin answer?
Andrei Volodin lui répond.
Solving an equation 2001-03-27
Jennifer pose la question :
How would I solve this equation? 1.6 = 2x/(.1-x) - the equation in parenthesises is raised to the second power. I know you take the square root of both sides, but there is where I get lost.
Leeanne Boehm lui répond.
12 RTV's 2001-03-27
Christine pose la question :
  1. In order to promote the 2000 Census and encourage participation, 12 Road Tour Vehicles(RTV's) set out from 12 locations across the US for a 10 week promotion tour last February. The RTV's reportedly traveled a total combined distance of 97,911 miles. What was the aberage number of miles traveled in a day by each RTV?

  2. 2. The 12 RTV's mentioned above traveled a total combined distance equivalent to traveling 12.35 times around the earth at the equator. To the closest mile, what is the radius of the earth? Use 3.14 as your approximation for pi.

Leeanne Boehm lui répond.
A sugar cane crop 2001-03-27
A student pose la question :
a sugar cane farmer harvested only 1/4 of his crop. he sold 2/3 of his harvest to the mill. what fraction of the total crop did he sell.

darens recipe for florida fudge calls for 5/8 cup of sugar. if he wants to make only 1/2 of the recipe how much sugar should he use.


Penny Nom lui répond.
Finite non-periodical numbers 2001-03-27
Wouter pose la question :
Is there anyone who knows the official name for decimal finite non-periodical numbers such as 0.4 or 0.25 as opposite of numbers like 0.3333333... or 0.28571428571428...?
Penny Nom lui répond.
Mistie, Tammy, and Jennifer 2001-03-27
Renee pose la question :
Mistie, Tammy, and Jennifer audition for parts in a big-budget remake of Bedtime for Bonzo. On the basis of their past experience and the caliber of competition they face, Mistie has a 40% chance of being hired, Tammy has a 50% chance, and Jennifer has a 30% chance. If exactly two of the three are cast, what is the probability that Mistie was rejected?
Andrei Volodin lui répond.
A box with an interior of 1.25 cubic feet 2001-03-26
Gabe pose la question :
I need a box with an interior of 1.25 cubic feet. I am using 3/4 inch material to make the box. What would the exterior dimensions be in inches?
Harley Weston lui répond.
66:1 2001-03-26
A student pose la question :
I need to know how to convert the ratio 66:1 to a percentage. I can not find an answer any where on-line when the second number is a 1.
Penny Nom lui répond.
Matrices 2001-03-26
Peg pose la question :
What are some applications of matrices, basic trigonometry, and linear systems in the real world? I'm writing and Algebra report about where these topics are used outside of the classroom.
Judi McDonald and Walter Whiteley lui répond.
Two ferry boats 2001-03-25
Gil pose la question :
Two ferry boats leave from opposite shores. One is faster than the other. They meet 720 yards from the nearest shore. They proceed to destination and upon returning they meet 400 yards from the other shore. What is the exact width of the river.
Penny Nom lui répond.
Airflow in windpipes 2001-03-25
Ena pose la question :
The volume of air flowing in windpipes is given by V=kpR4, where k is a constant, p is the pressure difference at each end, R is the radius. The radius will decrease with increased pressure, according to the formula: Ro - R = cp, where Ro is the windpipe radius when p=0 & c is a positive constant. R is restricted such that:
0 < 0.5*Ro < R < Ro,
find the factor by which the radius of the windpipe contracts to give maximum flow?

Harley Weston lui répond.
Perimeter of an acre 2001-03-24
Liz pose la question :
What is the perimeter of one acre of land?
Penny Nom lui répond.
Cube roots on a calculator 2001-03-24
Will pose la question :
Hi my name is Will.I have a question about the calculator TI-83 Plus or the use of a scientific calculator. It is about using them to turn a cubed root to a decimal. When using that for a rational and irrational number. Rational numbers is a number that terminates or repeates. A irrational number goes on and on and uses ... (like pie). Like when you type the cube root of 8 it gives you 2, and that is a rational number. The squre root of 2 is 1.41421356... that is irrational. So why is it when you put the cube root of 16 in the calculator it says 2.5198421 that is rational it terminates at the ninth digit and my float is set for the tenth? But why when you do it by hand you get the 2 times the cube root of 2 and that is irrational? Why is that?
Judi McDonald lui répond.
An elliptic tunnel 2001-03-24
Janna pose la question :
A tunnel is built under a river for a road 12m wide with a 2m sidewalk on either side. The top of the tunnel is semi-elliptical. A local bylaw stipulates that there must be a clearance of at least 3.6m at all points on the road. If the smallest possible ellipse is used, find the clearance at the center of the road.
Harley Weston lui répond.
A suspension bridge 2001-03-24
Janna pose la question :
The cables of a suspension bridge hang in a curve which approximates a parabola. The road bed passed through the vertex. If the supporting towers are 720m apart and 60m high, find:

a) an equation of the parabola (it's y = 1/2160x2)

b)the height of the cables at a point 30m from the vertex. I substituted 30 in for the x value and got 0.42 and the answer is 42. What did I do wrong?
Denis Hanson and Claude Tardif lui répond.

Two problems 2001-03-23
James pose la question :
Casey is a finanical consultant for ABC finance. She earns $456.21 weekly. Her annual group medical coverage costs $1942, of which ABC pays 65%. How much is deducted weekly for medical coverage?

and:

Eleanor demonstrates microwaves at the national home show. She is paid $7 for each of the first 7 demonstrations and $11 for each demonstration after 7. What is her commission for a day if she makes 12 demonstrations?

Penny Nom lui répond.
A famous landmark 2001-03-23
Corinne pose la question :
A family is traveling due west on a road that passes a famous landmark. At a given time the bearing to the landmark is N 62 degrees W, and after the family travels 5 miles farther the bearing is N 38 degrees W. What is the closest the family will come to the landmark while on the road?
Harley Weston lui répond.
Genealogy 2001-03-22
Brian pose la question :
In considering tracing genealogy the problem of a large and growing number of direct (grandparent) ancestors arose. Since the number of grandparents in any given generation doubles, for a person born in 2000 and assuming 25 year generations, in the year 1000 that person would have over one trillion direct ancestors in that year alone. Since estimates I have read place the total world population in 1000 at 250-300 million, the one trillion figure cannot be correct. I must be missing something in my calculations. Can you help provide the answer? While I am unlikely to be able to trace back to 1000, there is reason to believe 1250 is possible. Even in that year there would exist over one billion direct ancestors. That is certainly rather daunting and unlikely to be achieved if correct.
Penny Nom lui répond.
Camille Jordan 2001-03-22
Missy pose la question :
PLEASE SEND ME INFORMATION ON CAMILLE JORDAN AND HIS WORK IN ABSTRACT ALGEBRA
Rick Seaman lui répond.
Factoring 2001-03-22
Kaleena pose la question :
Factor this equation: 5x7-10x5+4x3-8x
Harley Weston lui répond.
Why exactly can't you divide fractions? 2001-03-22
Dennis pose la question :
Why exactly can't you divide fractions?
Penny Nom lui répond.
The repetend in repeating decimals 2001-03-21
Sharon pose la question :
What is the name for the bar over the repetend in repeating decimals? Also, what is the name of the long division "house"?
Penny Nom lui répond.
A bargin with the devil 2001-03-21
DJ pose la question :
There once was a boy who spent all his time dreaming about getting rich. " I would do anything to be rich". The devil, hearing this, appeared before the boy and offered to make him rich. "See that bridge?" said the devil. Just walk across and I will double your money you have now. In fact, each time you cross I will double your money. There is just one thing you must give me $24 after each crossing. The boy agreed. He crossed the bridge, stopped to count his money and, and sure enough, it had doubled. He paid the devil $24 and crossed again. Again his money doubled. He paid another $24 and crossed a third time. Again his money had doubled, but this time there was only $24 left which he had to pay the devil so he was left with nothing. The devil laughed and vanished.
  1. How much money did the boy start with?

Penny Nom lui répond.
Timing with hour glasses 2001-03-20
Nathan pose la question :
How can a chef use an 11 minute hour glass and a seven minute hour glass to time a vegtable that needs to be steamed for 15 minutes.
Leeanne Boehm lui répond.
Radicals 2001-03-18
Nikki pose la question :
3) squareroot of x2 + 10x + 25

4) sixthroot of (m + 4)6

5) cuberoot of -64r6w15

.
.
.
.

Penny Nom lui répond.
Systems of equations 2001-03-16
joy pose la question :
How do u solve problems using systems of equations?
~ finding x and y~

ex:

26 = 3x - 2y
42 = 4x + y


Penny Nom lui répond.
How can you prove a quadrilateral to be a parallelogram? 2001-03-16
Joy pose la question :
How can you prove a quadrilateral to be a parallelogram?
Walter Whiteley lui répond.
Probability and a three digit number 2001-03-15
Glenn pose la question :
A THREE DIGIT NUMBER IS SELECTED AT RANDOM. WHAT IS THE PROBABILITY THAT NON OF THE THREE DIGITS ARE PRIME.
Harley Weston lui répond.
Names of the polygons 2001-03-15
Sami pose la question :
I was asked to find out what the names for different polygons were. The only two I cannot find are the names for a polygon with 30 sides and a polygon with 40 sides. I would really appreciate it if you could help me. Thank you very much.
Harley Weston lui répond.
The bond angles of a tetrahedral polygon 2001-03-14
Nishi pose la question :
how do i prove (a simply as possible) why the bond angles of a tetrahedral polygon are 109.5 degrees? *i already have two explanations that i don't understand. one is about "theory of dot products" and "vectors" and a hook-like symbol w/ a cosine, and the other has an incomprhensible diagram w/ difficult notation- PLEASE BE SIMPLE! thanks sooo much
Harley Weston lui répond.
A jogger 2001-03-12
Bill pose la question :
At time t=0 a jogger is running at a velocity of 300 meters per minute. The jogger is slowing down with a negative acceleration that is directly propotional to time t. This brings the jogger to a stop in 10 minutes.

a) write an expression for the velocity of the jogger at time t.

b) what is the total distance traveled by the jogger in that 10-minute interval.


Harley Weston lui répond.
Quadratic equations 2001-03-11
Philip pose la question :
I am a student in the UK and i am in secondary school and i am doing my GCSE next year.

here are my questions:

solve the following equations correct to 2 decimal each time.

[1] 2xsquared + 5x = 1

[2] 3xsquared(2x+1)=1

[3] xsquared + 7x + 2 = 2x + 4

[4] 5xsquared - 3x = xsquared + 4


Penny Nom lui répond.
Math Puzzle 2001-03-10
Vanessa pose la question :
I have a math puzzle. I have been working on it for over 2 weeks. Here it is: use the numbers 1-25 each only once. The rows across are an equation and the columns down are an equation. There are 25 boxes. You have to use the order of operation x and / first then = and -. Some of the answers are -numbers.
.
.
.

Claude Tardif lui répond.
Two locus problems 2001-03-08
Janna pose la question :
A point P moves such that it is always equidistant from the point G(2,5) and the line defined by y=3. Find the equation of the locus. I got as far as the equation: 3y2 -4y = -x2 + 4x - 16 and didn't know what to do from there. Of, course that whole equation could be wrong.

Question 2: P is always twice as far from A(8,0) as it is from B(2,0). Find the equation of the locus. Once again, I got as far as y2 = -x2 -8x -56, and got stuck.


Harley Weston lui répond.
The angle of elevation 2001-03-08
Jeffrey pose la question :
At a Certain time, a vertical pole 3m tall cast a 4m shadow. What is the angle of elevation of the sun?
Harley Weston lui répond.
4160 2001-03-07
Jessica pose la question :
The product of two consecutive page numbers in this book is 4160. What are the page numbers?
Penny Nom lui répond.
problem of the week 2001-03-06
Peggy Allan pose la question :
My son has been challenged with "the problem of the week" and I am unable to assist him in finding a reasonable solution.

Problem 1,

Julio needs to draw a line segment 15cm long. He does not have a ruler. He does have some sheets of letter size paper 28 X 21.5 cm. Describe how Julio can use the paper to measur 15 cm.

Claude Tardif lui répond.
The substitution method 2001-03-05
A student pose la question :
Solve each system of equations by the substitution method. Show your work.
  1. y = 8
    7x = 1 - y

  2. y = x - 1
    4x - y = 19

Penny Nom lui répond.
Powers 2001-03-04
A student pose la question :
Hey, can you show me how you do ..

(2xy)to the 3rd power (x) to the 2nd power?


Penny Nom lui répond.
Coins and monomials 2001-03-04
A student pose la question :
Tokola has 5 coins with a total value of $1.05. He canot make change for a dollar, 5 cents, 10 cents, 25 cent, or 50 cents. What 5 coins does he have?

and

Determine whether 6c-d is a monmial. Explain why or why not.


Penny Nom lui répond.
Arc of a sphere 2001-03-04
Some students pose la question :
My friends and i have a geometry project and we cannot seem to figure out how to find the arc of a sphere.
Harley Weston lui répond.
What is the value of n? 2001-03-03
Adam pose la question :
When I add n to 7 and then divide my answer by 4,I get 5. What is the value of n?
Penny Nom lui répond.
Spins of a roulette wheel 2001-03-02
Bob pose la question :
Here's a problem I'm working on myself.....If you look at six consecutive spins of a roulette wheel, how many combinations of red and black are possible? I.E. BRRBRB, BBBBBR, BBRRRB......ETC.....
Claude Tardif lui répond.
How tall is the tree? 2001-03-02
Ronda pose la question :
a tree's shadow is 42 ft. long. There is a stop sign that is right next to it and it is 18 ft. tall and it's shadow is 12 ft. long. How tall is the tree?
Penny Nom lui répond.
Is there an odd and even function? 2001-03-02
Saima pose la question :
Is there a function that is both even and odd at the same time? In other words, is there a function that can pass the y-axis, x-axis, and origin symmetry test?
Claude Tardif and Penny Nom lui répond.
P vs NP problem 2001-03-01
Roy pose la question :
What math journals would publish a proposed solution to the P vs NP problem when the work has been done by an amateur mathematician who has no degree in math?
Claude Tardif lui répond.
Converting percents to decimals 2001-03-01
Elliot pose la question :
My math question is about Converting Percents to Decimals, here it is-

Convert 37 1/2 = ?


Penny Nom lui répond.
The price of a carpet 2001-03-01
Amber pose la question :
i have to calculate the square footage of carpet for me room and im not quite sure how to do that. the carpet is $2.08 per sq. ft. and my room is 12x11ft.
Penny Nom lui répond.
Solve for the variable 2001-02-28
Ashley pose la question :
I've got 2 questions. We (my dad and I) can not figure them out. please help me.
  1. 21 = 9 - 2 (4a + 2) and I am supposed to find out what the variable is.

  2. 2/3 n + 3/8 n = 15/16 (those are fractions). Again, I need to find out what the variable is.

Penny Nom lui répond.
Fibonacci 2001-02-28
Shona pose la question :
We have been doing pattern finding with him, talking to a friend he mentioned the "Fibbinacci Series" ?, while I have tried to find a bit about it, how works etc.. what it is about, I have not really found out much, what I have I feel is way beyond him, but am still curious to know the basics of it myself. Would you be able to tell me in laymans language. Would be very much appreciated.
Claude Tardif lui répond.
Three sheep 2001-02-28
A student pose la question :
A farm sold three sheep. the weight of the three sheep combine wae 152 lbs. The smallest sheep weighted 7 lbs less than the middle size sheep. The largest sheep weighted three times the smallest sheep. what is the weight of each sheep?
Penny Nom lui répond.
T-numbers an T-totals 2001-02-27
Mr. M. Wiseman pose la question :
Investigate the relationship between the T-total and the T-number.
Penny Nom lui répond.
Lotto 6-49 2001-02-27
A student pose la question :
I am a secondary student and I was wondering if there was a better way to find out how many combinations and what they are in the lotto 6/49 than writing them out on a piece of paper. Any help you can provide me with would be greatly appreciated.
Penny Mon lui répond.
The n-th place of pi 2001-02-27
Andrew pose la question :
I have always wondered; is it possible to find the value of an irrational number, such as (phi) at it's nth decimal place???

You would plug the decimal place into the formula and the value would be given at the specified decimal place.

When we look at the expression { (sqr 5 + 1)/2 } we are in a sense visualising the number in it's entirety, so the formula may include elements of the above expression in some form.
Claude Tardif lui répond.

Domain and Range and Zeros 2001-02-27
Beth pose la question :
1. f(x)=15-2x-x2

2. g(t)=square root of 4-t2

3. y=t-3/t2-t-6


Penny Nom lui répond.
MIRA 2001-02-27
Constantinos pose la question :
What is a "mira," and how is it used in terms of topology (in geometry)? If you can answer my question, and even refer me to online or other resources to find out more, I would greatly appreciate it.
Walter Whiteley lui répond.
Shape names 2001-02-26
Paul pose la question :
I have been asked to give names of shapes from A to Z . I can only find 14 shapes can you help..... I'm missing letters b, g, j, l, m, n, u, v, w, x, y, z.
Harley Weston lui répond.
Solve for two variables 2001-02-25
A student pose la question :
How do I solve for %1 and %2 in the following formula when T1, T2 and T3 are known? %1 and %2 are ratios of the same element, therefore %1 + %2 = 100%

(%1 x T1) + (%2 x T2) = T3

Penny Nom lui répond.
Shape, symmetry, measurement and space 2001-02-24
Marilyn pose la question :
I have to write in detail about how young children learn about shape, symmetry, measurement and space. It is not activities I need it is how the children learn. How/why their brain takes it all in
Walter Whiteley lui répond.
Solving Equations 2001-02-23
Stephanie pose la question :
Do you know who came up with solving equations?
Do you have any web-sites that can give me good information on solving equations?
Do you know any history on solving equations?
Do you know what solving equations is used for?
And finally............Sorry about all of the questions :)
Has the form of solving equations changed from the time it came out to now?

Juci McDonald lui répond.
What is my name? 2001-02-23
Julia pose la question :
My perimeter is 12 cm. My sides are all equal. The sum of half my sides is equal to 6 cm. How many sides do I have? What is my name?
Penny Nom lui répond.
Difference of Squares 2001-02-22
Bruno-Pierre pose la question :
I noticed the other day that if you substract two consecutive squared positive numbers, you end up with the same result as if you add up the two numbers.

Ex. 5 and 6 (2 consecutive positive numbers)
52 = 25
62 = 36
36 - 25 = 11 (Substraction of the squared numbers)
5 + 6 = 11 (Sum of the numbers)

A more algebric view:
a2 - b2 = a + b where a and b are consecutive positive positive numbers. (b = a + 1)

I wondered if this rule had a name, and who discovered it.


Penny Nom lui répond.
The domain of the derivative 2001-02-22
Wayne pose la question :
I know that the domain of f'(x) is a subset of the domain of f(x). Is it necessarily true that the subset will have at most one less element than the domain of the original function?
Harley Wesston lui répond.
Find the two numbers 2001-02-21
A grade 6 student pose la question :
Find the two numbers:
5 is a common factor;
100 is a common multiple;
neither number is a mulitple of the other;
both are even.

Penny Nom lui répond.
Mr. Moser's roof 2001-02-21
Michelle pose la question :
Mr. Moser is planning to replace the roof of his home. He needs to order a pack of shingles. Each pack covers 100 sq. ft. of roof. Without a ladder, Mr. Moser can not climb to the roof to measure it. Instead, he measures his attic and finds it to be 40 ft. long, 24 ft. wide, and 5 ft. high at the peak of the roof which is in the center of the house. Although the roof is even with the side walls, he estimates the roof line continues 1.5 ft. beyond the front and back walls. How many full packs of shingles should Mr. Moser order to cover his roof?
Penny Nom lui répond.
Winning percentages 2001-02-21
Mike pose la question :
TEAM A WINS 55% OF GAMES PLAYED

TEAM B WINS 40% OF GAMES PLAYED AGAINST THE SAME OPPONENTS

WHAT WINNING PERCENTAGE SHOULD BE EXPECTED WHEN TEAM A PLAYS TEAM B (NEUTRAL SITE)?


Harley Weston lui répond.
Congruence and symmetry 2001-02-21
Chris pose la question :
My name is Chris and I am a second-grade teacher. I would like to know what the difference is between congruent and symmetry, and how do I explain this to my class? I know that congruent means the same, and symmetry is two identical sides. Is there a difference between the two? I know there must be, but I don't know what or how to explain these two terms.
Walter Whiteley lui répond.
Faces 2001-02-21
Sandy pose la question :
How many faces are there on a sphere?

What are the faces of a cone?

What is the definition of a "face" of a 3D object?


Walter Whiteley lui répond.
Math game 24 2001-02-21
Kristi pose la question :
We have a game we play in math class called 24 game. In it each card has 4 numbers on it. Each number can only be used once, in any order, using multiplication, subtraction, division, or addition. We are stuck on one and wondered if you could help. The four numbers are: 3, 3, 5, 7. And they must equal 24. Any clues?
Claude Tardif lui répond.
The law of cosines in the real world 2001-02-21
Hope pose la question :
Do you have any examles and/or labs that show how the law of cosines is used in the real world?
Harley Weston lui répond.
Undecagon 2001-02-21
Karen pose la question :
I need to know what kind of a polygon an undecagon is and how many sides it has. This is a problem in my math book.
Penny Nom and Michael Tsatsomeros lui répond.
Ratios 2001-02-20
Louise pose la question :
there are 3 people and they decide to share their tips (working in a restaurant) ann gets £180 tony £130 peter £90 total amount is £36 what share should they get.
Penny Nom lui répond.
Expanding determinants using minors 2001-02-20
A student pose la question :
Question:
1) Determinants by expansion by minors.

i)
| 1 2 1 2 1 |
| 1 0 0 1 0 |
| 0 1 1 0 1 |
| 1 1 2 2 1 |
| 0 1 1 0 2 |


Harley Weston lui répond.
A remainder of 1 2001-02-20
A student pose la question :
what is the smallest positive integer which has a remainder of one when divided by 2,3,4,5 and 6
Penny Nom lui répond.
A pole next to a building 2001-02-20
Robert L. Haun pose la question :
A pole 100 feet tall is erected next to a building 10' X 10' X 10' . Object is to cut off the pole so the upper end remains touching the part cut off, while the cut-off portion touches the cutoff point, the edge of the building and the ground. Note assume the pole is touching the building and is "very thin" What is/are the cutoff points?
Penny Nom lui répond.
Cubic feet 2001-02-20
Frances pose la question :
I'm trying to calculate cubic feet from the dimensions of a machine given in inches.

Width = 32"
Height = 79.5"
Length = 91.5"
Weight = 3920 lbs

Please help? Obviously I've been away from school too long!!


Penny Nom lui répond.
Law of cosines 2001-02-20
Emily pose la question :
I missed a few days of class and I can't figure out how to solve Law of Cosines problems. I have the notes and formulas but I can't figure out how to do the math involved to answer the problems. I am also getting confused about how to use degrees and seconds in the Law of Sine and Cosine. I can't seem to get the correct answers and I don't really know how to solve them and enter them into my TI 86.
Harley Weston lui répond.
Difference of squares 2001-02-20
Janna pose la question :
Hi! I was just wondering how you would factor x2 - 9y2.
Harley Weston lui répond.
Delivering firwood 2001-02-20
Jackie pose la question :
Two college students earn extra money on weekends by delivering firwood in thier pickup truck. They have found that they can sell x cords per weekend at a price of p dollars per cord, where x=75-3/5 p. The students buy the firewood from a supplier who charges them C dollars for x cords to the equation C=500+15 x+1/5 x2.

a) find a function f such that P=f(p), where P dollars is the profit per weekend for the students if they charge p dollars per cord.

b)find the profit P dollars if p=$95

Penny Nom lui répond.
g(g+5)=0 2001-02-20
Jenna pose la question :
g(g + 5) = 0
Penny Nom lui répond.
The area of platts 2001-02-20
Steve pose la question :
I have to calculate the areas of different "platts" of land from a map, and the only thing I have are the four side measures. There are some cases where no sides are parallel, no lengths the same, and no angles are given, and I was wondering how to calculate the area of such figures. I've attached a rough sketch of a typical platt's shape.
Walter Whiteley lui répond.
Dividing polynomials 2001-02-19
Janna pose la question :
I have two questions involving dividing polynomials by polynomials.

Here's the first one:

Two factors of 12a4 -39a2 + 8a - 8a3 + 12 are a - 2 and 2a + 1. Find the other factors. The other question I'm stuck on is: When 10x3 + mx2 - x + 10 is divided by 5x-3, the quotient is 2x2 + nx - 2 and the remainder is 4. Find the values of m and n.


Penny Nom lui répond.
Adding functions 2001-02-19
Jackie pose la question :
f(x) = x2 + 1; g(x) = x2 - 1

find
a) ((f+g) of h)) (x)
b) ((f-g) of h)) (x)
c) ((f of h) - (g of h)) (x)


Penny Nom lui répond.
Working on commission 2001-02-17
Jay pose la question :
Ron the realtor is offered a job directly out of real-estate school. He has a choice as to which way he will receive his salary the first year.

Salary Plan 1: He would receive a base pay of $2000 per month plus a 3% commission on each sale.

Salary Plan 2: No base pay but a 6% commission on each sale.


Write an equation to determine when it would be better to switch from the first plan to the second plan. Give a one- or two-sentence answer that includes Ron`s sales in a month. Round to the nearest dollar, if necessary.

Leeanne Boehm and Penny Nom lui répond.
Some fractions 2001-02-17
Lady Bird pose la question :
Mr. Bob has 3/4 of a bottle of medicine left. He takes the medicine three times a day. Each dose is 1/16 of the bottle. How many days will it take for Mr. Bob to finish the bottle?

My friend gave me a problem to solve and it is so hard. Can you help me solve it? Here it is: If g- 4.8 = 9.66 and e-1/3 = 1/8, what is the sum of g and e?

Mariko's mother used ribbon to wrap 3 birthday gifts. She had 3 ribbons and each was 72 inches long. She used 8/9 of the first ribbon, 2/3 of the second ribbon, and 5/6 of the the third ribbon. How many feet did she use?


Leeanne Boehm and Penny Nom lui répond.
Angles in a polygon 2001-02-17
Joan pose la question :
How many sides does a polygon have if its smallest interior angle is 120 degrees and each sucessive angle is 5 degrees greater than the predecessor?
Penny Nom lui répond.
Percentage increase 2001-02-17
Bob pose la question :
If sales for jan 2001 are 154 vs 105 for 2000 - the increase total presented to my office is +46% - how does that compute. Please give me the equation.
Penny Nom lui répond.
Differentiation of y = x n 2001-02-17
Jashan pose la question :
i am studying differentation at the moment i have drawn some graphs such as y=x 2. i have found the formula for the gradient of this curve, this being 2x obtained by using differentation, but i need to know the general case for the formula where y=xn in order for me to understand this topic more throughly, i would also like to know how u derived this general formula
Harley Weston lui répond.
A four digit number 2001-02-17
Dean pose la question :
Need to find a 4 digit number that can be divided by 2, 3, 4, 5, 6, 7, 8, 9, and will always have a remainder of 1 in the answer.
Penny Nom lui répond.
Triakis 2001-02-17
Anne Grant pose la question :
I am a grade 8 teacher and have come across the term "Triakis" used with Tetrahedron, octahedron, and hexahedron. What does this term refer to, and what's the difference between a triakis polyhedron and one that is not?

I'd also like to know what is meant by the term antiprism, as opposed to prism.


Penny Nom lui répond.
Symmetry 2001-02-15
Sonam pose la question :
What is symmetry?
Who invented symmetry?
what are the different kinds of symmetry?

Penny Nom lui répond.
A quartic equation 2001-02-15
George pose la question :
Let P(x) = x4 + ax3 + bx2 + cx + d. The graph of y = P(x) is symmetric with respect to the y-axis, has a relative max. at (0,1) and has an absolute min. at (q, -3)

a) determine the values for a, b c, and d using these values, write an equation for P(x)
b) find all possible values for q.


Harley Weston lui répond.
A four dimensional object 2001-02-14
A student pose la question :
Can you give me some examples of a four dimensional object you can find around your house?
Harley Weston lui répond.
Linear equations 2001-02-13
Jamie pose la question :
I have a question how do you do linear equation?
Penny Nom lui répond.
Rewrite as an addition problem and Simplify 2001-02-13
A student pose la question :
On my homework sheet it says "Rewrite as an addition problem and Simplify" and the gives this problem "16 - 120 ="
how do i do that problem?

Penny Nom lui répond.
Books and cars 2001-02-13
Aquilya pose la question :
  1. A pile of books is 96.08cm. If each book is 0.8cm thick. How many books are in th pile?

  2. 2. A car travels 9.84km on 0.6 litres of petrol. How far will the car travel on 3.7 litres of petrol?

Penny Nom lui répond.
L - R 2001-02-12
A student pose la question :
If L = (a-b)-c and R=a- ( b-c), then L-R = ???
Penny Nom lui répond.
An order relation 2001-02-12
Amy pose la question :
What is an order relation?
Claude Tardif lui répond.
Two inequalities 2001-02-12
A student pose la question :
If 3
Leeanne Boehm lui répond.
Part of a part 2001-02-11
Katie pose la question :
Hello! I was looking at your Fraction questions and since i am pursuing to be an elementry school teacher i feel i don't understand one of your responses. How would you explain this to an elem, midd, and high school student. Even me myself-in college really does not understand. The question was: When you multiply two positive fractions less than 1, how does the answer compare to the size of the fraction? Why?
Penny Nom lui répond.
A merchant from Pisa 2001-02-11
A student pose la question :
A merchand doing business is Lucca doubled his money there and spent 12 denarii. On leaving, he went to Florence, where he also doubled his mone and spent 12 denarii. Returning home to Pisa, he there doubled his money and again spent 12 denarii, nothing remaining. How much did he have in the beginning?
Claude Tardif lui répond.
Chris' cards 2001-02-11
A student pose la question :
Chris gave Jane x cards. He gave Bety one card more than he gave Jane and he gave Paul two cards fewer than he gave Betty. In terms of x, how many cards did Chris give Bety, Jane, and Paul together?
Penny Nom lui répond.
percent 2001-02-11
A student pose la question :
what is 1.5% of 20386.01?
Penny Nom lui répond.
Multiplying one and two digit numbers 2001-02-11
Marty pose la question :
When multiplying do you put the number you are multiplying by on the top or the bottom. Example if you are multiplying by 6's would you write the problem 6
x 2
or 2
x 6
Maybe it just doesn't matter. But when you get to double digits, the double digit always goes on the top?

Penny Nom lui répond.
Lucky dip 2001-02-09
Andrew pose la question :
I buy 8 lucky dip (random number) panels, each panel has 6 numbers chosen at random from 49. I never seem to cover more than 32 different numbers on average, over the total 48 numbers chosen, which seems low? How can I calculate the probability of 32 different numbers or 33 diferent numbers?
Claude Tardif lui répond.
A dog and a rabbit 2001-02-09
Josh pose la question :

1. A dog and a rabbit are 160 meters a part for every 9 meters that the dog runs , the rabbit jumps 7 meters. How many meters must the dog run in order to vertake the rabbit???

2. A cars odometer reads 15951 KM. Find the least number of kilomaters to travel until the palindromic number appears???


Leeanne Boehm lui répond.
What is wrong with these probelms? 2001-02-09
Cindy pose la question :
Hi, I am a planning on becomming a teacher and i am asked to find out what is wrong with these probelms and how i would go about showing a student what is wrong with them!!

Error in patterns:
13/35=1/5; 27/73=2/3; 16/64=1/4

4/5+2/3=6/8; 2/5+3/4=5/9; 7/8+1/3=8/11

2/3*3=6/9; 1/4*6=6/24; 4/5*2=8/10


Leeanne Boehm and Penny Nom lui répond.
The odds of winning 2001-02-09
Anna pose la question :
The odds of winning in a game are 3 out of 10. How many times would one have to play the game in order to be sure they would win?
Leeanne Boehm lui répond.
Kinds of lines 2001-02-09
Robyn pose la question :
What are the different kinds/types of lines?
Leeanne Boehm lui répond.
An irregular polygon 2001-02-09
Jason pose la question :
I have a 5 sided irregular polygon I am trying to figure out the area of. There are no right angles in the polygon as far as I can tell. I do not know any angles.
Chris Fisher lui répond.
Partitioning of an arbitrary line segment 2001-02-08
David pose la question :
Did Euclid's Geometry include a construction for the regular partitioning of an arbitrary line segment?
Chris Fisher lui répond.
Bicycles and phone calls 2001-02-08
Sarah pose la question :
  1. A bicycle has a diameter of 66 centimeters. How many times must the tire rotate to travel 1 kilometer?explain answer.

  2. Becky want to make a long distance call to her friend Sarah from a pay telephone.She has $5.00 in change.The call costs $0.90 for the first three minutes and $0.24 for each additional minute.How long can Becky talk to Sarah?

Leeanne Boehm lui répond.
Buckets of golf balls 2001-02-08
A student pose la question :
A bucket containing 40 golf balls weighs 135 ounces. The same bucket with 20 golf balls weighs 75 ounces. What is the weight of the bucket?
Claude Tardif lui répond.
Find an exprression for f(x) 2001-02-07
A 12th grade AP Calc student pose la question :
Let f be the function defined for all x > -5 and having the following properties. Find an expression for f(x).

i) f ''(x) = 1/ (x+5)1/3 for all x in the domain of f

ii) the line tangent to the graph of f at (4,2) has an angle of inclination of 45 degress.


Harley Weston lui répond.
The "goesinta" box 2001-02-07
Bridget pose la question :
We are looking for the "proper" name of the "box" that is drawn around the dividend on a division problem:

  ___ 3)12 

It has always been a family joke to call it the "goesinta" box, but a search of several reference sources hasn't yielded an answer --

This is a question of curiosity rather than a question for homework.


Claude Tardif lui répond.
(-2b+3)(-b-1) 2001-02-06
Melissa pose la question :
Alright, lets say you are multiplying (-2b+3)(-b-1) and you are using "FOIL" first you would get : 2b2+2b-3b-3 then you add like-terms. when multiplying,if the bases are the same, add the exponents...does the same thing apply when you are adding the results of the multiplication even though it's addition?

would the answer be 2b3-3b-3 or would it be 2b2-b-3?


Penny Nom lui répond.
23 + 17 * 2 / 8 + 11 = 13 2001-02-02
David pose la question :
My child is working through basic operations, and gave this problem:

23 + 17 * 2 / 8 + 11 = 13

The teacher wants the parenthesis to be put in the right places to come up with 13.
Claude Tardif lui répond.

Which fraction is greater? 2001-02-01
Carol pose la question :
Hello My name is Carol I am a student teacher! I am asked to aproach these students on their problems. I am unsure of how to explain to them that these are wrong. Can you help? Thanks.

Iris claims that if we have two positive rational numbers, the one with the greatest numerator is the greatest.

Shirly claim that if we have two positive rational numbers, the one with the greatest denominator is the least. Thanks!


Claude Tardif lui répond.
Gross markup 2001-02-01
Chris pose la question :
TotalGMSell
$265040%$4,416.67

GM is Gross Margin? do you have any meanings for this like Gross markup etc?

Can you show me the working of how you get the 2650 to sell at 4416.67


Penny Nom lui répond.
Finding roots 2001-02-01
A student pose la question :
My math problem is right now we are working on roots. I don't quite understand how to find the answer to the problems, i was wondering what is the easiest, and fastest way to find the answers to roots?
Penny Nom and Claude Tardif lui répond.
The solutions of a quadratic 2001-01-30
A student pose la question :
  1. Show that the product of the solutions of ax2 + bx + c = 0 is c/a.

  2. For each equation under the given condition, (a) find k and
    (b) find the other solution.
    kx2 - 2x + k = 0; one solution is -3

Penny Nom lui répond.
Why is 0! = 1? 2001-01-30
Diane pose la question :
Every math book always claims that 1!=1 and 0!=1 are givens, and that we should just memorize it. i understand the 1! part, but where is the basis for claiming that 0!=1????
Walter Whiteley lui répond.
Unscramble these words 2001-01-30
Myosha pose la question :
Hi my name is Myosha. I would be part of the secondary(6~9) class. I need you to unscramble these words & define them for me.

  1. edicnreeff

  2. rtgeare

  3. itfrnoca

  4. lmicdae

  5. sdvioini

  6. imrretepe


Claude Tardif lui répond.
Two number theory questions 2001-01-30
Richie pose la question :
i have two questions and they are:
  1. the product of three consecutive prime numbers is 7429. Find the product of the smallest and largest of these three integers.

  2. the least common multiple of two relatively prime positive integers, a and b, is 144. if a (a>or=2) is as small as possible, compute the value of b.

Penny Nom lui répond.
Subsets of the natural numbers 2001-01-30
Christina pose la question :
How do I explain why the set of natural numbers (N) cannot be equivalent to one of its finite subsets?
Penny Nom lui répond.
Fractions of fractions 2001-01-30
Katie pose la question :
When you multiply two positive fractions less than 1, how does the answer compare to the size of the fraction? Why?
Penny Nom lui répond.
Crossing the dessert 2001-01-29
Zach pose la question :
An Explorer needed to make a 5 day trip across a dessert. Each man with him could carry exactly 3 days food and water. For one man how many men will it take to cross the dessert?
Claude Tardif lui répond.
Geometric and arithmetic sequences 2001-01-26
Garry pose la question :
what are the equations for geometric and arithmetic sequences?

also, what are the equations for finding the sums of those series?


Leeanne Boehm and Penny Nom lui répond.
Processing speed 2001-01-26
Zac pose la question :
A COMPUTOR IS ADVERTISED AS HAVING A PROCESSING SPEED OF 11 MILLION INSTRUCTIONS PER SECOND. ON THE AVERAGE, HOW LONG DOSE IT TAKE TO PROCESS ONE INSTRUCTION AT SUCH A SPEED?
Leeanne Boehm lui répond.
Equilateral 2001-01-25
A student pose la question :
I AM 9 YEARS OLD AND I HAVE HOMEWORK. I WOULD LIKE TO KNOW IF THERE IS SUCH A THING AS A EQUILATERAL SQUARE.
Penny Nom lui répond.
Rotation 2001-01-25
A student pose la question :
If I have a rectangle 2inches long and 4 inches wide and I rotate the rectangle 45 degrees will the length still be 2 inches?
Penny Nom lui répond.
Conversions 2001-01-24
Tanya pose la question :
I have 2 questions
  1. covert 628 kilometers to miles.(round off your answer to two decimal places.)

  2. a new clerk in your office is to earn $200 per week. If she works 30.5 hours each week, what is her hourly rate? (round off your answer to the nearest hundreth, that is, to the nearest cent.)

Penny Nom lui répond.
Building a circular silo 2001-01-24
Natasha pose la question :
We wish to build a circular silo with internal diameter 10 feet. How much concrete will we need to pour the foundation, if we only need a 1 foot wide and 1 foot deep ring on which the silo walls will sit? Assume the 4 inch thick silo wall rests on the middle of the ring.
Penny Nom lui répond.
Factoring 2001-01-24
Danielle pose la question :
4(x+1)2+y(x+1)
Penny Nom lui répond.
Factoring a trinomial 2001-01-24
Kyle pose la question :
I am an eighth grade student.I can not figure out the following problem. 4x2 + 2x - 20
Leeanne Boehm lui répond.
14, with 5 ODD numbers 2001-01-23
Robyn Ernst pose la question :
How can you get 14, with 5 ODD numbers?
Claude Tardif lui répond.
Cincinnati to Winston-Salem 2001-01-23
Belinda pose la question :
Joan Bedney travels from Cincinnati to Winston-Salem at an average rate of 40 miles per hour and returns at an average rate of 60 miles per hour. What is her average speed for the trip?
Leeanne Boehm and Claude Tardif lui répond.
1 + 1 = 1 2001-01-23
Stephanie pose la question :
My friend has this as a bonus question the other day and I want to figure it out. I don't know how 1+1 in any form could equal 1. Please let me know how you come about geting that.
Claude Tardif lui répond.
7x6 by doubling 2001-01-23
A student pose la question :
Can you think of a way to use doubling to multiply 6x7?
Allen Herman lui répond.
What number from 1 to 25 has the most factors? 2001-01-23
John pose la question :
What number from 1 to 25 has the most factors?
Penny Nom lui répond.
0,2,3,6,7,1,9,4,5,8 2001-01-23
Tami pose la question :
What is the sequence of the numbers 0,2,3,6,7,1,9,4,5,8
Claude Tardif lui répond.
Some algebra 2001-01-23
Thomas pose la question :
If a is 4 more than the quotient of b and 3, and if b=2, then what is the value of a?
Penny Nom lui répond.
The sum of the angles in a polygon 2001-01-23
A student pose la question :
What is the sum of the measures (interior angles) in an octagon ... heptagon ... decagon.
Penny Nom lui répond.
The hypotenuse of a right triangle 2001-01-22
Phillipe pose la question :
How do you find the hypotenuse of a right triangle?
Penny Nom lui répond.
Conditional probabiity 2001-01-22
Wallace Yang pose la question :
A pair of six-sided fair dice is thrown. Find the probability that the sum is 10 or greater if it is given that a 5 appears on at least one of the dice.
Penny Nom and Claude Tardif lui répond.
Square feet and cubic feet 2001-01-21
Jenny pose la question :
How do I convert square feet to cubic feet? If I have 2000 square feet then how many cubic feet do I have?
Harley Weston lui répond.
25% mark up 2001-01-20
Vivian pose la question :
If it costs me $100.00 to manufacture an item and I want to sell it at a 25% mark up, why do I get different answers when I perform the operation the following ways?

1. $100.00 x 25% = $25.00
$100.00 + $25.00 - $125.00

2. $100.00 / .75 = $133.334

Should these two not be equal?
Penny Nom and Claude Tardif lui répond.

A prism 2001-01-18
Nigel Ayling pose la question :
What is the mathematical definition of a prism, I am confused by the following definitions as they appear to be contradicto...
Walter Whiteley lui répond.
Proportionality: direct and indirect 2001-01-18
Nancy Ellis pose la question :
What is the difference between directly proportional and indirectly proportional?
Leeanne Boehm lui répond.
More repeating decimals 2001-01-17
Alan pose la question :
I am neither a math teacher nor a student, but I hope you will consider my question anyway. I recently was discussing repeated decimals with a friend, and went on the web to find out more about a pattern was looking for years ago. In doing so I came upon your correspondence on repeating decimals.
.
.
.

Chris Fisher and Penny Nom lui répond.
Greatest common factor 2001-01-17
A teacher pose la question :
I'm a teacher at a local Middle School and I would like the answers for the following questions.

What is the greatest common factor for..

546 and 780

156 and 732

.
.
.

Leeanne Boehm and Penny Nom lui répond.
Motivators 2001-01-16
Michelle Stapley pose la question :
Do you know of any (or where I can find) student motivators for math at the secondary level? Basically any way I can motivate my students to WANT to learn math.
Penny Nom lui répond.
A problem with distance 2001-01-16
A student pose la question :
For what values of a is the distance between P(a, 3) and Q(5, 2a) greater than the square root of 26.
Penny Nom lui répond.
Some complex problems 2001-01-15
Nick pose la question :
I am having enormous difficulty with one question in my maths homework. The question is shown below. If anybody out there can find the answers and show the workings and help me to understand.
Harley Weston lui répond.
Polynomials and exponents 2001-01-15
A student pose la question :
I am duing a project in math on polynomials and exponents. I need a real life usage of polynomials and exponents for my project.
Penny Nom lui répond.
The path of a cannonball 2001-01-15
A student pose la question :
Artillerymen on a hillside are trying to hit a target behind a mountain on the other side of a river. Their cannon is at (x, y) = (3, 250) where x is in kilometers and y is in meters. The target is at (x, y) = (-2, 50). In order to avoid hitting the mountain on the other side of the river, the projectile from the cannon must go through the point (x, y) = (-1, 410).

Write the equation for the problem.


Penny Nom lui répond.
Some terms in a sequence 2001-01-15
jamie pose la question :
Please help as soon as possible! i am stuck with some terms in a sequence. the terms are 1st term=1, 2nd term=10, 3rd term=35, 4th term=84, 5th term=165, 6th term=286. can anyone tell me the formula for the nth term? n is term number
Sukanta Pati lui répond.
Arranging some numbers 2001-01-14
Denise pose la question :
Arrange the following numerals in two groups of four each so that each group will add to give the same sum. 1 2 3 4 5 7 8 9
Penny Nom anf Claude Tardif lui répond.
Exponents 2001-01-14
A student pose la question :
I am wondering if a number raised to the second power is "squared" and a number raised to the third power is "cubed" is there a name for any number raised to any other power.
Harley Weston lui répond.
Vitamins A and B 2001-01-14
Sara pose la question :
A diet is to include at least 140 mg of Vitamin A and at least 145 mg of vitamin B. these requirements are to be obtained from two types of food. type X contains 10 mg of vitamin A and 20 mg of vitamin B per pound. Type Y contains 30 mg of vitamin A and 15 mg of vitamin B per pound. if type X food costs $12 and Type Y $8 per pound, how many pounds of each type of food should be purchased to satisfy the requirements at the minimum cost?
Claude Tardif and Harley Weston lui répond.
Compression by a factor of ? 2001-01-12
Wayne pose la question :
Given an equation like y = (1/2) (x-3)2 + 6, when describing the distortion from the base curve y = x2 is it correct to say there is a vertical compression by a factor of 2, or by a factor of 1/2 ? Which is more correct? I have seen both versions in different high school texts, and I am now unsure which is more correct.
Harley Weston lui répond.
Completing the square 2001-01-12
Jacky Lam pose la question :
A friend told me that completing square not only can find the vertex but also the roots of a quadratic equation. Is it possible? How? Can you show me how to find the roots of the following equation using completing the square?

8x2 + 8x + 4


Penny Nom lui répond.
64.5% profit 2001-01-12
Ethel pose la question :
IF I PURCHASE AN ITEM FOR $2.00 AND I WANT TO RESELL IT WITH A MARGIN OF GROSS PROFIT OF 64.5% WHAT FORMULA DO I USE TO ARRIVE AT THAT RESELL FIGURE?
Penny Nom lui répond.
Blood flow and age 2001-01-11
Gayle pose la question :
I don't understand the second part of this problem Here is the first part that was correct. A 35yr old has 100% blood flow. A 65yr old has 64% blood flow. Find the rate of change per yr in the percent of blood flow. (This part is correct) m=(64-100)/(35-65)= -36/30= -1.2 per year of blood flow.

Now, here is the second part I DON'T UNDERSTAND! .Let b represent the percent of blood flow and a represent a person's age. Write an equation that you could use to predict the percent of blood flow for a person of any age over 35.


Penny Nom lui répond.
Place value chart 2001-01-11
Charles pose la question :
Can you send me a pictorial example of a place value chart?
Harley Weston lui répond.
8, 4, 2, 18, 1, 9 2001-01-11
Neyra pose la question :
Place each number below in one of the blanks to create the most meaningful and realistic story possible.
Claude Tardif lui répond.
A 1 from 35 lottery 2001-01-11
Jamie pose la question :
A number is randomly drawn from an urn containing 35 balls numbered 00 to 34.

How to win

Division 1 Match the number drawn
Division 2 Match the last digit of the number drawn

Calculation of probabilities for this lottery:...


Claude Tardif and Penny Nom lui répond.
x^5 + y^5 + z^5 = w^5 2001-01-11
Samuel Brown pose la question :
x5 + y5 + z5 = w5 I have no idea whether or not this is possible.
Claude Tardif lui répond.
The sum of all ten-digit numbers. 2001-01-10
John pose la question :
Compute the sum of all ten-digit numbers. Can you determine the sum of all n -digit numbers?
Sukanta Pati lui répond.
Is n^2 - 2 a multiple of n - 4? 2001-01-10
John pose la question :
Find all positive integers n so that n2 - 2 is a multiple of n - 4.
Sukanta Pati lui répond.
Four crayons 2001-01-10
Neyra Espinoza pose la question :
You have four crayons (red, blue, yellow, green). If you line them up, how many different combinations can you get?
Patrick Maidorn lui répond.
The Pythagorean Theorem 2001-01-08
Megan pose la question :
Why the Pythagorean Theorem so important in our lives and what is it's history?
Penny Nom lui répond.
Multiplication of fractions 2001-01-08
Angela pose la question :
Questions:

1. represent multiplication of fractions via an area model

2. describe why, not just how, to round decimals


Penny Nom lui répond.
cot(arcsin 3/5) 2001-01-07
Jason pose la question :
Find value. Assume that all angles are in Quadrant 1.

cot(arcsin 3/5)


Harley Weston lui répond.
The city transit system 2001-01-07
Jacky pose la question :
The city transit system carries an average of 9450 bus riders a day, for a fare of $1.75 each. The city wants to reduce car pollution by increasing ridership and to maximize the transit system's revenue at the same time. A survey indicates that the number of riders will increase by 150 for every $0.05 decrease in fare.
Harley Weston lui répond.
Women mathematicians 2001-01-07
Kisha pose la question :
Can you please tell me names of at least five female math teachers who changed history back then?
Penny Nom lui répond.
Derfs, Enajs and Sivads 2001-01-07
John and Norman pose la question :
All Derfs are Enajs. One-third of all Enajs are Derfs. Half of all Sivads are Enajs. One Sivad is a Derf. Eight Sivads are Enajs. The number of Enajs is 90. How many Enajs are neither Derf nor Sivad?
Penny Nom lui répond.
A dollar, quarter, dime, nickle and penny 2001-01-07
Sarah pose la question :
Arnold has a dollar coin, one dime, one quarter, one nickel, and a penny. The number of different sums of money that can be formed using three coins is...
Penny Nom lui répond.
The pythagorean theorem in everyday life 2001-01-06
Josh pose la question :
What are some ways that we use the pythagorean theorem in jobs, or even in everyday life?
Claude tardif lui répond.
Two questions 2001-01-04
Justine pose la question :
first: A diagonal of a rectangle is the square root of 13 meters and the area of the rectangle is 6 meters squared. What are the dimensions of the rectangle?

last: Find the ordered triple of nonzero digits (A,B,C) for which (AA)squared=BBCC where AA and BBCC are respectively, two-digit and four-digit base-ten numerals.


Penny Nom lui répond.
Three dice 2001-01-03
John Read pose la question :
I have three dice (A, B, C.) Three sides of each dice are blank. Three sides of each dice have a number. When the dice are thrown, it must be possible to result in the numbers 1 to 49 in any combinations without doubling up on any figure. i.e. Different combinations resulting in the same end number. I managed to get from 1 to 47 before getting stuck.
Claude Tardif lui répond.
Why the change from commas between every 3rd digit, to spaces instead? 2001-01-03
Clarende Duby pose la question :
Why the change from commas between every 3rd digit, to spaces instead? For example: Three million three hundred thirty-three thousand three hundred thirty-three written like: 3 333 333 instead of 3,333,333? Does it have something to do with standardizing mathematical notation worldwide?
Harley Weston lui répond.
30% of 80 2001-01-03
Denise pose la question :
Could you please tell me what 30% of 80 is?
Penny Nom lui répond.
The laws of sines and cosines 2001-01-02
Faydene pose la question :
Can the sine /cosine rule be applied to a right -angle triangle to find a particular solution or are these 'rules' applied only when the triangle is not right angled?
Penny Nom lui répond.
Filling a tank 2001-01-02
Liting pose la question :
Water flows into a rectangle tank which measures 4 m by 3 m by 2.8 m through a cylindrical pipe of radius 2.4 cm. If the rate at which the water flows into the tank is 8 km/h, find how long it takes to fill the tank.
Penny Nom lui répond.
Polite numbers 2001-01-02
A student pose la question :
A positive whole number, greater than 1, is said to be a polite number if it can be expressed as a sum of consecutive whole numbers

Find all the polite numbers less than 21. Find a pattern in the numbers that are not polite. Explain why every odd number greater than one must be polite.


Penny Nom lui répond.
A quarter-circle and two semi-circles 2000-12-31
Christopher pose la question :
Inside the quarter-circle are two semi-circles with the same radius, (r). Which has a greater area, G or L?
Penny Nom lui répond.
Height of the lamp 2000-12-31
Joey pose la question :
The figure shows a lamp located three units to the right of the y-axis and a shadow created by the elliptical region x2 + 4y2 < 5. If the point (-5,0) is on the edge of the shadow, how far above the x-axis is the lamp located?
Harley Weston lui répond.
Repeating decimal notation 2000-12-31
Clarende Duby pose la question :
I have seen single repeating decimals for ex. 1/3 = 0.3 with the dot above the 3 to represent the repeating decimal. Then, there is the more common form of the bar over the top of the repeating number or group of numbers (called the period?). Which notation is correct?
Penny Nom lui répond.
Bush fractals 2000-12-30
Anita Wisecup pose la question :
My son has a report due on fractals. He needs information on bush fractals, but we cannot seem to find anything out about them.
Penny Nom lui répond.
Solving x - sin(x) = constant 2000-12-29
Keith Roble pose la question :
If x is in radians, how do you solve for x, where: x-sin(x) = constant?
Harley Weston lui répond.
Solving an equation 2000-12-29
Bob pose la question :
Would you be able to help me solve this math equation..

Solve for b, 2 [b - (q + s)] / q = s


Penny Nom lui répond.
A pair of numbers whose GCF is 28 2000-12-27
John pose la question :
Name 2 different pairs of numbers whose GCF is 28.
Penny Nom lui répond.
Some prime conjectures 2000-12-24
Tarrasita pose la question :
I was given some homework to investigate the following conjectures on prime numbers

1) There is at least one prime between consecutive square numbers.

2) Every prime except 2 and 3 is of the form 6n+1 where n is a natural number.

3) Any odd prime which is of the form 4n+1 is equal to the sum of two perfect squares.


Harley Weston lui répond.
A lampost and its shadow 2000-12-24
Laura pose la question :
A lamppost line EC casts a shadow line AC. A 30 cm ruler line DB has been moved from A so that it's shadow falls just within the shadow of the lamppost.
  1. Suppose the length of the ruler's shadow is 42 cm. What is the slope of the imaginary line AE?

  2. Suppose the lamppost's shadow is 15 m. long. How tall is the lamppost?

Penny Nom lui répond.
Cats and dogs 2000-12-24
A student pose la question :
Brian has fourteen pets. All of his pets are cats and dogs. Brian has four more cats than dogs. How many dogs does he have?
Penny Nom lui répond.
Calculating the tax 2000-12-22
A grocer pose la question :
I have a small grocery store. I have a bag of money containing $325. This represents the mornings receipts and a tax of 5.75% is included in the total. How can I separate the gross take from the tax take so that I'll know how much is mine and how much is the state's?
Penny Nom lui répond.
How do you integrate secant(theta)? 2000-12-22
Robert Williamson pose la question :
How do you integrate secant(theta)?

I know the answer is ln [sec(theta) + tan(theta)] but how do you get there?


Claude tardif lui répond.
An infinite series 2000-12-16
John pose la question :
summation(n=1 to infinity)[n sin(1/(2n))]n
Harley Weston lui répond.
A Trapezium problem 2000-12-15
Ben pose la question :
A trapezium has a perimeter of 22cm. The 2 parallel sides are such that the length of one is three times the length of the other. The non-parallel sides are equal. If the distance between the parallel sides is 4cm, find the lengths of the 4 sides.
Claude Tardif lui répond.
Factoring (u-v)3+v-u 2000-12-15
A parent pose la question :
I am a middle school teacher and a parent. I am snowed in and trying to help my 9th grader get ready for 9 weeks exams. I have tried to factor this problem to no avail. (u-v)^3+v-u. I have the answer but I need to know how it is done.
Penny Nom lui répond.
When did the man go out? 2000-12-14
Rajesh pose la question :
A man goes out in time between 5 and 6 and when he comes back he observes that two hands have interchanged position. Find when the man did go out?
Penny Nom lui répond.
Three problems 2000-12-14
Sarah pose la question :
Hi, my name is Sarah, and I'm asking this question on behalf of niece who is in secondary two. Thank you.

Q1. What is the angle formed by the hour hand and the minute hand of a 12 hour clock at 5.50pm.

.
.
.

Penny Nom lui répond.
What is the difference between Mean and Average? 2000-12-13
Julie pose la question :
What is the difference between Mean and Average? My thinking is the average, is the equal to the sum of all numbers divided by the number of numbers added together. But the mean, I think should be calculated by adding the largest and smallest numbers in the set and them dividing by 2. (which is the point where 1/2 the numbers are higher and 1/2 the numbers are lower)
Patrick Maidorn and Penny Nom lui répond.
Prime factorization 2000-12-13
A student pose la question :
What is the prime factorization for 250 1296 and 2400
Penny Nom lui répond.
A limit using l'hopital's rule 2000-12-13
Wassim pose la question :
I need to know how to solve the:
limits of (x ( to the power lamda) -1 )/LAMDA when lamda tends to zero ( the answer is that the functional form is ln x) and I still don't know how using hopital rule leads to this answer.

Harley Weston lui répond.
Scientific notation 2000-12-12
Guy pose la question :
How do I express 1.000.000 in scientific notation?
Harley Weston lui répond.
Direct and inverse variation 2000-12-12
Ashley pose la question :
I'm stuck on this unit of direct and inverse variation..please and my problems and show me how to do each PLEASE!!!

Assume that y varies directly as x

If y= -4 when x = 2, find y when x= -6

Assume that y varies inversely as x

If y =-4 when x=2, find y when x =-6


Penny Nom lui répond.
Divisibility by 16 2000-12-12
Shiling pose la question :
A number can be divided by 16 if and only if its 1st four digits can be divided by 16. How can you prove that?
Penny Nom lui répond.
A chemist had 8 flasks 2000-12-10
Jimmy pose la question :
A chemist had 8 flasks capable of holding 12, 15, 27, 35, 37, 40, 53 and 69 fluid ounces respectively. He filled some with water and then filled all the rest except one with alcohol. He used exactly one and a half times as much alcohol as water. Which flask was left empty and which were left with water and which with alcohol?
Claude Tardif lui répond.
Volume of a trough 2000-12-09
Matt pose la question :
I have been given the information of the length of the trough, and the end pieces are isosceles triangles, and two equal sides of the triangle are given. I cannot seem to find the answer, nor anything in my book relating to the question.
Harley Weston lui répond.
Mixed Fractions 2000-12-09
Tim Finch pose la question :
My son is having problems with mixed decimals and mixed fractions.. I am unable to find any information or examples on this subject so I can show him how to do it.. for example how do you make a mixed decimal or fraction out of 7/16
Penny Nom lui répond.
Is this a right triangle? 2000-12-08
Alicia pose la question :
How would you set-up and answer a problem like these one? Triangle ABC has vertices A(-2,2), B(1,-2), and C (1,2). Use slopes to determine if the triangle is a right triangle.
Penny Nom lui répond.
Networks of satellites and linear spaces 2000-12-08
David pose la question :
Let us suppose some companies have collaborated to place several satellites in orbit. Let us call the set of all satellites that a given company helped place in orbit a network. Finally let us assume the following 4 rules.
  1. There are at least two distinct satellites.


  2. For each pair of satellites there is exactly one network containing them.


  3. Each network contains at least two distinct satellites.


  4. For each network, there is a satellite not in it.

What is the least number of satellites.

what is the least number of networks?


Penny Nom lui répond.
Fibonacci 2000-12-07
A student pose la question :
Can you give me any info about Fibonacci??
Penny Nom lui répond.
Kai's bike 2000-12-07
Fumiko Muhammad pose la question :
The wheels on Kai's bike are 27 inches in diameter. His little sister, Masako, has a bike with wheels that are 20 inches in diameter.

a. How far will Kai go in one complete turn of his wheels?

b. How far will Masacko go in one complete turn of her wheels?

c. How far will Kai go in 500 turns of his wheels?

d. How far will Masako go in 500 turns of her wheels?


Penny Nom lui répond.
Pizza delivery 2000-12-07
Meghan pose la question :
3 men give 10 dollars each to a pizza deliver driver and when he gets back to his work the manager says to the pizza driver the bill was actually 25 dollar so he has to returns 5 dollars. on his way to the mens house he the driver decides to kept 2 dollars for himself and he gives 1 dollar back to each of the men. So each one of the men actually paid 9 dollars. but 9 times 3 is 27 plus the other 2 that the driver took equals 29 so where did the other dollar go.
Harley Weston lui répond.
Optical illusions 2000-12-06
Jessica pose la question :
Hi, my name is Jessica, 7th grade, and Im doing a Math Fair project on optical illusions. As one of the required factors, we need a "mathmatical significance" paragraph. Unfortunatley, I can only think of one way that optical illusions have to do with math, and thats time because some optical illusions tell you to look at the picture for a certain amount of time.
Penny Nom lui répond.
< and > Which one is which? 2000-12-06
Alice pose la question :
This grandmother forgot and wants to know the correct for greater and the one for lesser.....

the two are < and > Which one is which?


Penny Nom lui répond.
A point that a group of lines pass through 2000-12-05
Ross pose la question :
A point that a group of lines pass through is called a________?
Chris Fisher lui répond.
Scheduling a golf vacation 2000-12-05
Michael pose la question :
I'm having a problem scheduling matches for a golf vacation. We have 12 people playing 7 rounds of golf in 7 days. We play 2 man teams vs. 2 man teams everyday.Is there a formula so that you play WITH a different partner everyday and AGAINST as many different people as possible? Thank You for any help you may be.
Penny Nom lui répond.
Calculating your grade 2000-12-04
Jack pose la question :
I got an 80 on test 1 and a 65 on test 2. The first test is worth 35% of our total grade and the second is worth 40%. What is my grade right now?
Penny Nom lui répond.
The aspect ratio of a rectangle 2000-12-04
Ron Delavigne pose la question :
The aspect ratio of this rectangle is 4:3. That is A to B is 3. And B to C is 4. If I know the lenght of A to C is 19 inches, how can I find the length of A to B, and B to C.
Penny Nom lui répond.
Parabolas in life 2000-12-03
Ashley pose la question :
I am a student and my teacher recently gave us the assignment of writing a portfolio on parabolas in life and finding examples, three to be in fact, only we have to go into detail about only one. We have been instructed to include such terms as: axis of symmetry, completing the square, parabola, quadratic formula, standard form (vertex form) and vertex. We also must include in our detailed example an equation of the parabola and very specific details, PLEASE HELP!
Harley Weston lui répond.
Equivalent fractions 2000-12-03
A student pose la question :
please explain to us how to find the answer to this problem, we need three fractions that name the same amount as 2
Penny Nom lui répond.
Estimating the time to complete a job 2000-12-03
Jack Hook pose la question :
I'm a contractor and need to estimate how much time it will take me to do a specific job. A previous job I did was 6,480.16 Square Feet and I was able to paint it in 31.5 hours. In estimating my next job, how many hours will it take me to paint 11,000 Sqare Feet.
Penny Nom lui répond.
A non-integrable function 2000-12-03
Mark Spilker pose la question :
I have a proof that I cannot do here it goes.
Let F(x)= 1 if x is a rational number 0 if x is an irrational number Prove the function is not intregrable on the interval (0,1). Hint: Show that no matter how small the norm of the partition, the Riemann Sum for the SigmaNotation F(wi) DeltaiX is not unique.

Harley Weston lui répond.
Two more problems 2000-12-01
Michael pose la question :
first question:
The mean of three test grades is 74. What must a fourth grade be to increase the mean to 78?

final question:
The product of two consecutive odd positive integers added to their sum is 119. What are these two integers?


Claude Tardif lui répond.
Triangles and trigonometry 2000-11-30
Mose pose la question :
If I have a right triangle, and I know the lengths of all three sides, is there a formula that will allow me to determine the measurements of the 2 non right angles?
Harley Weston lui répond.
A 16 slice pizza 2000-11-30
A student pose la question :
What is 5/8 of a 16 slice pizza?
Penny Nom lui répond.
An integration problem 2000-11-30
A student pose la question :
If a>0 and the integral from b to 0 of 1/(1+x) equals 1/2 the integral from a to 0 of 1/(1+x), express "b" in terms of "a"
Claude tardif lui répond.
The astronomers' calendar 2000-11-29
Show_Li pose la question :
The calendar that astronomers use began on Jan. 1, 4713 B.C. on that day, the julian calendar, the lunar calendar, and roman tax system calendar all coincided. This won't happen again until 3267 A.D.
(a). How many years ago was the astronomer's calendar started?
(b). Find the number of years between times that the three calendars coincided.

Penny Nom lui répond.
Trig identity crisis 2000-11-29
Rhiannon pose la question :
I have tried many times to find the answer to these problems but I can't I am in grade 12
  1. tan(x)=csc2(x)-cot2(x)
  2. cos(x)/csc(x)-2sin(x)=tan(x)/1-tan(x)
  3. cos(x)[ tan2(x)1-1]/cos2(x)+sin2(x)=sec(x)

Harley Weston lui répond.
Vector Problem 2000-11-27
Ben pose la question :
An aircraft can fly 260km/h in still air and the wind is blowing at 70km/h towards the West. In what direction should the aircraft head so that its actual velocity is on a bearing of 030 degrees?
Harley Weston lui répond.
Power series representations 2000-11-27
Grace pose la question :
Is there a systematic way of finding a power series representation of a function? I understand that you have to manipulate the function so that it is of the form 1/(1-x), but beyond that I am lost.
Harley Weston lui répond.
Order of operations 2000-11-26
Margaret Pratt pose la question :
My daughter has a math question and I am afraid I am of no help. Can you help? 2x5/2+1-5= She arrives at 8 as the answer and has been told this is incorrect. Any help you can give would be appreciated.
Penny Nom lui répond.
A complex calculation 2000-11-24
Angie pose la question :
Multiply (3-2i)2=32-2(3)(2i)+(2i)2
Penny Nom lui répond.
A piecewise linear equation 2000-11-24
Jacky pose la question :
There is a light bulb and it is given that the light bulb cost $0.75 and the cost of operating it is $0.0081 per hour. From the information give, I came up with the linear equation: Let c be total cost and Let h be hours used. Therefore: c = 0.0081h + 0.75 represents the total cost of the light bulb and the electricity. However, the second part of the question added the fact that the light bulb will only last for 800 hours. If the light bulb is replaced as soon as it burns out exactly after every 800 hours, how can I write an equation that represents that? Is it possible? What would it look like on the graph.
Harley Weston lui répond.
What are adjacent angles that equal 360 called? 2000-11-22
David pose la question :
I know that supplementary angles add to 180 degrees and that commplementary angles add up to be 90 degrees, but what are adjacent angles that equal 360 degrees called?
Chris Fisher lui répond.
Comparing an integral and a sum 2000-11-21
Douglas Norberg pose la question :
A fellow teacher asked me about a problem she wanted to give to her students. It involved whether to take a million dollars or a penny doubled a number of times. I was able to determine the number must have been .01 * 230 which is about $10 million and a lot more than $1 million. To check that I was right I used a spreadsheet and did a Riemann sum.

When I finished I reasoned that I had done the task in several steps and I could have done it in 1 step. Thus I integrated .01 * 2x from 0 through 30 but the number I got was $15,490,820.0324. Why the difference?


Harley Weston lui répond.
5 spades 2000-11-21
Matt pose la question :
In a standard deck of 52 card how many would you have to draw (without looking at them) to be absolutely certain that you had 5 spades?
Claude Tardif lui répond.
Range of a function 2000-11-21
David Bell pose la question :
Given a rational function such as f(x) = (8x-3)/(4x-1). How can the range be found.
Penny Nom lui répond.
Net, gross and vat 2000-11-20
Chris pose la question :
I have my gross but want to find out the net so I know how much the VAT is?
Penny Nom lui répond.
Integral solutions 2000-11-20
David pose la question :
determine all pairs of integers (x,y) which satisfy the equation

6x2 - 3xy - 13x + 5y = -11

I got

y= (6x2-13x+11)/(3x-5)

and i don't konw how to continue


Claude Tardif lui répond.
Permutations vs. combinations 2000-11-20
Ashleigh pose la question :
How do you tell whether the problem is a permutation or a combination?
Walter Whiteley lui répond.
Bridges and parabolas 2000-11-18
Lauren pose la question :
My name is Lauren, and Im a secondary school student in Ontario. For my gr11 advanced math class I have to find out how and why parabolics are used in arch bridges and write 3 paragraphs on it. People who cohse satelites and whatnot are lucky - I've found a ton of info, but for arch bridges there seems to be nothing.
Harley Weston lui répond.
Find the 3D angle 2000-11-18
Jacky pose la question :
Included is the diagram. I am trying to find out the angle of ABC. Is it possible? How?
Penny Nom lui répond.
Inscribing a circle in a rhombus 2000-11-16
Jacky pose la question :
A rhombus ABCD is drawn in which the diagonals are 12 and 20 units long. A circle is inscribed in the quadrilateral with the centre of the circle right on the intersection point of the 2 diagonals. The circumference of the circle touches all 4 sides of the rhombus. Is it possible to find the radius of the inscribed circle? If so, how and what is it?
Chris Fisher lui répond.
Expanding a garden 2000-11-16
Janeth Rojas pose la question :
Mr Jones's garden has an area of 21 squares meters. He wants to increase its size by 1/2. Draw a picture to show what his new garden might look like. Be sure to give the new area and demensions, and show your reasoning.
Penny Nom lui répond.
Volume of a box 2000-11-15
A student pose la question :
A box 3" wide and 2" deep is to have a volume of 2 cubic feet. How long must the box be?

How many pieces of lumber are stacked in a pile 2" high if each board is 3/8" thick?


Penny Nom lui répond.
Dividing with decimals 2000-11-15
Alex pose la question :
I teach math and my class and I were discussing the dividing of decimals. I explained that if there is a decimal in the divisor, it needs to be moved and so does the decimal in the dividend. My question is why is it necessary to move the decimal point in the divisor before dividing?
Penny Nom lui répond.
Domain of a function 2000-11-15
Mickey pose la question :
state any restrictions on the domain of the function.

y = 5x - 12 over 27x + 6 x does not equal what________?


Penny Nom lui répond.
Henri Leon Lebesgue 2000-11-14
Mandy pose la question :
I have a report that I have to do on Henri Leon Lebesgue for my Foundations of College Math class. I have searched for him on erols, google, yahoo and a few other search sites and I have only come up with one page that offered some information. I was wondering if anyone knew anything about him, or a web page that I could get some info.
Harley Weston lui répond.
Solving an equation 2000-11-14
Heather pose la question :
4x-3 = 3x+4 these kinds of problems i dont get but everything else in my math class i have got. i just dont understand it.
Penny Nom lui répond.
Five digit palindromes 2000-11-12
Jacky pose la question :
Positive integers such as 1287821 and 4554, in which the number is unchanged when the digits are reversed, are called palindromes. The number of five-digit integers larger than or equal to 10,000 which are not palindromes is... a. 10 000 b. 81 000 c. 89100 d. 90 000 e. 99 100
Penny Mom lui répond.
Static electricity on an airplane 2000-11-12
John pose la question :
What discharges an airplane of static electricity in a electric storm when it is flying. I assume the charge is on the out side of the plane but when does it get discharged, or does it occur at landing?
Ted Mathie lui répond.
Euler's Formula 2000-11-11
Denise Roberts pose la question :
I'm trying to design a unit (possibly involving a Webquest) on Polyhedra and I cannot find a formula I once used. The formula involved the number of vertices (V), edges (E), and faces (F) of the polyhedra.
Walter Whiteley lui répond.
The magnitude of a complex number 2000-11-11
Jeremy pose la question :
Recently, we started studying how to graph complex numbers. Our math teacher said to use what would normally be the x-axis as the real-axis and to use the y-axis as the imaginary-axis. However, when he started talking about how to calculate magnitude, that's when I became confused. For instance...
Walter Whiteley lui répond.
Infinite Geometric Series 2000-11-10
Sam Carter pose la question :
I ran into a problem when studying how to find the sum of an infinite geometric series. My math book attempts to explain the concept by giving formulas involving sigma and |r|, but it does not really explain how to go about finding the sum of an infinite geometric series. If you could either help me with this or point me in the direction of an informative website that could help me, I'd appreciate it.
Harley Weston lui répond.
Rhombuses 2000-11-07
Melissa pose la question :
What in real life is the shape of a rhombus?
Chris Fisher and Walter Whiteley lui répond.
How big is a trillion? 2000-11-07
A teacher pose la question :
How can you explain how much a trillion is to a 5th grade class?
Penny Nom lui répond.
Parking spaces 2000-11-07
Lydia pose la question :
A parking lot has 4 aisles. Each aisle is about 40 yards long and has parking places on both sides. If a parking place is 3 yards wide, how many cars can the parking lot hold?
Penny Nom lui répond.
How many tens are in 400? 2000-11-07
A student pose la question :
How many tens are in 400?
Penny Nom lui répond.
Crown molding mitre cuts 2000-11-06
Jim Tomfohrde pose la question :
My question has to do with making mitre cuts when installing crown molding. Crown molding is the trim that is put up at the top of walls with one edge on the wall and the other edge on the ceiling. To make a mitre cut on your mitre saw for a 90-degree corner you can lay the molding flat on the saw base, set the bevel of the blade to 34 degrees and the mitre to 31.5 degrees (these may be slightly appoximate). Of course depending on which piece of molding you're cutting you will cut one end or the other, or use the left or right end. These angles allow the cuts to line up and form a seamless corner when they're put in place on the wall/ceiling at 90 degrees. My question is this - is there some mathematical formula from which the 34 degrees and 31.5 degrees are derived. I want to know this because in many cases the corner is not 90 degrees but can be more or less, and in these instances I would like to know if I can calculate the bevel and mitre to use based on the angle of the corner.
Harley Weston lui répond.
Graphing F(x) = 3x 2000-11-06
Jose pose la question :
graph the exponential problem F(x)=3x
Harley Weston lui répond.
Banana yogurt 2000-11-03
James pose la question :
A grocery store has 100 cartons of banana yogurt in stock.Each carton contains 12 cup of banana yogurts.The probability that a cup has fewer than 20 banana chunks in it is 10 %. So,What is the probability that between 15 and 25 (inclusive) cartons out of the 100 cartons have exactly 3 cups with fewer than 20 banana chunks?
Harley Weston lui répond.
Expected number 2000-11-02
James pose la question :
1)There are 40,25,50 students in the traditional,reformed,and reformed traditional Calculas sections taught by three teachers. On one fine day the three sections congregate together to watch the NOVA video tape on Fermat's Last Theorem.

a) A student is randomly selected from he crowed of students.What is the expected number of students in the same section of this student?

****this question which i did not have any idea to do as follow for the part b
b) If one of the three teachers is selected at random, what is the expected number of students taught by is teacher?


Harley Weston lui répond.
Two problems 2000-11-02
Michael pose la question :
Question:
I mistakenly divided a number by 5 when I should have multiplied by 5. FInd my percent of error.

Next Question:
How many odd numbers are between 10 and 9,999 from the digits 0-9 if each digit is used once per number.


Penny Nom lui répond.
Length of a shadow 2000-11-01
Jessy pose la question :
A man who is six feet tall is walking away from a street light that is fifteen feet tall. How long is the man's shadow when he is ten feet away from the light?
Penny Nom lui répond.
Symmetry 2000-11-01
A student pose la question :
I am a 6th grader look for material on mathametical symmetry . Most of the material I have found is science related . I have to write a paper on this . Any resource info you could lead me to would be helpful. Thank you for your time.
Chris Fisher lui répond.
Perfect numbers 2000-10-31
A student pose la question :
I was wondering if you could help me answer a question my pre-algebra teacher asked in class the other day. He asked if we knew what the perfect numbers where.

He told us the first number is 6 the second number is 28 but the third he did not tell us. Do you know what the third perfect number is?
Paul Betts and Chris Fisher lui répond.

Factoring a cubic 2000-10-31
A student pose la question :
Factor Completely

18p3 - 51p2 - 135p


Paul Betts and Penny Nom lui répond.
Lobbing a tennis ball 2000-10-31
Alex pose la question :
If a tennis ball is lobbed into the air with an initial upward velocity of 12 meters per second, its velocity and height will be functions of time in flight described by the following rules:

V=12-9.8T and H=1+12T-4.9T 2

Find the maximum height of the tennis ball and the time it takes to reach that height.


Penny Nom lui répond.
False Positives 2000-10-29
James pose la question :
A rare disease infected 1 in 1000 people in the population. A test for the disease is accurate 99% of the time when given to an infected person and also when given to a heathy person.
  1. Fill out a two-tier tree diagram and find the probability of the false positive(i.e the conditional probabily of being healty even when tested postive by the test) Comment on the result?

  2. ...

Penny Nom lui répond.
Square roots 2000-10-29
Pamela pose la question :
HERE GOES(I WILL USE Q AS THE SYMBOL FOR SQUARE ROOT):

8(Q2) - 5(Q2) + Q2

SECOND PROBELM IS

(1 + Q2)2

LAST ONE

3/(2-Q5)


Claude Tardif lui répond.
Overlapping a circle and a square 2000-10-28
Jacky pose la question :
A square with a dimension 20 by 20cm. and a quarter of the circle with the radius of 25cm (A quater of a circle is created by 2 cuts that are perpendicular bisectors of each other where the intersecting point is at the centre of the circle). With these 2 pieces, the 2 pieces are placed over each other in which the 90o angle of the quarter circle matches with one of the right angles on the square. Now, calculate the overlapping area of the 2 figures.
Chris Fisher and Harley Weston lui répond.
Find the rule 2000-10-27
Kelsa and Linda pose la question :
Find the rule: It had 13 in a circle then 2 blank circles then 31 in a circle then two more blank circles. Could you please help us.
Penny Nom lui répond.
Developing a community garden 2000-10-26
adam pose la question :
Robin's class is developing a community garden. There are 15 students in Robin's class. They volunteer to work in a community garden at various times during the school week. Robin's teacher says it will take about 3 weeks to complete the project if 3 students work 1 hour each day. Some students can work on more than one day. The following table lists the number of students who can work on various days.
.
.
.

Penny Nom lui répond.
Cutting the lawn 2000-10-26
Kacie pose la question :
Ellen can mow a lawn in 2 hours. Mary can mow the same lawn in 1.5 hours. How long would it take them to mow the lawn together?
Penny Nom lui répond.
A zip code problem 2000-10-26
Rob Mathis pose la question :
Find the zip code of a place in a county so that the product of it and the zip code of another place in another county of the same name, but in a different state, is an exact multiple of the number 123456789
Claude Tardif lui répond.
The ages of three daughters 2000-10-25
Andrea pose la question :
An encyclopedia saleman call at a home. The woman who answers the door says she will buy something from him if he can give the ages of her three children. The first clue, she says, is the three ages multiplied together equal 36. he responds that he needs more infomration, so she says that the threee ages add up to the number of the bus that passed by (the prof did not give us this number) He thinks for a while and says he needs one more clue. So she says, my youngest child has red hair, and he is able to answer and make the sale. what are the ages of the three children? (hint: the salesman needed all three clues to get the answer).
Penny Nom lui répond.
Assessment and portfolios relating to math 2000-10-24
Jackie pose la question :
I will be assisting in a presentation for grades 4-6 on assessment and portfolios relating to math. If anyone has some ideas will love to hear them. I have checked out a few sites on the net
Diane Hanson lui répond.
Divisibility by 9 2000-10-24
Kelera pose la question :
If the sum of the digits of a number is divisible by 9, then the number itself it divisible by 9. Why is that? How do you explain this?
Penny Nom lui répond.
A sequence question 2000-10-23
Chell pose la question :
I have the following sequence:

4 16 37 58 89 145 42 20

I have no clue how to arrive at an answer. I've checked to see if it can be defined as an arithmetic or geometric series, and it can't. I've looked for primes and noticed that 37 and 89 are the only primes ... but from there I've lost. Nothing I've tried seems to work, so please help! Thanks a million!!!!


Chris Fisher lui répond.
Working together on a job 2000-10-23
Nicole pose la question :
WORKING TOGETHER ON A JOB: Patrice, by himself can paint 4 rooms in 10 hours. If he hires April to help they can do the same job together in 6 hours. If he lets April work alone , how long will it take her to paint 4 rooms?
Claude Tardif lui répond.
Concavity 2000-10-22
Alex pose la question :
the question is: on what interval is f(x)=(x2)(ex)?

ive found the 2nd derivative which is ex(x2+4x+2) and i did the quadratic to get -2-20.5 and -2+20.5, but i dont know what the interval is.
Harley Weston lui répond.

Tapes and CD's 2000-10-22
Arnold pose la question :
Nicole has 25 CDs and tapes altogether. When she tries to pair them up, she has 4 CDs left over. How many tapes does Nicole have?
Penny Nom lui répond.
The scale on a map 2000-10-21
Caroline pose la question :
On a map scale of 1:15000 the distance between two buildings is 31.4cm what is the actual distance in km.
Penny Nom lui répond.
Connecting to a water line 2000-10-20
Vanja pose la question :
My question is...A house is to be connected to a new water main that runs along the line y=2/3x-1. The connection point at the house has coordinates (2,9), where the units represent metres. What lenght of plastic pipe is needed to connect to the water main at the closest point?
Penny Nom lui répond.
The perimeter of a football field 2000-10-18
Paige pose la question :
The width of a football field is 67ft greater than the length. The perimeter is 480ft What is the width and length?
Penny Nom lui répond.
Dividing fractions 2000-10-18
Paula pose la question :
Why do you have to change the division sign to a multiplication sign and invert the fraction that follows the division sign in order to get the answer to a division problem when you're working with fractions?
Penny Nom lui répond.
Transporting bananas 2000-10-18
Krystie pose la question :
A farm has 45 bananas, a man has to take a truck and transport 15 bananas to a market that is 15 miles away. Every mile he travels, he must eat a banana. I have to get at least one banana to the market
Penny Nom lui répond.
A chord length 2000-10-17
Al Paas pose la question :
How to determine the length of a chord given the diameter of the circle and the maximum distance from the chord to The circle?
Chris Fisher lui répond.
Multiplying decimals 2000-10-16
Lily pose la question :
I need help with mutiplying decimals (example) 2.28*0.48( * = times).
Harley Weston lui répond.
Area of shapes 2000-10-14
Melanie pose la question :
What is the formula to calculate the area of different shapes?
Harley Weston lui répond.
2-step equations 2000-10-11
Jen pose la question :
i don't get how you find the answer to these equations

140= -4 -12e

x/-2 + 6 = 4


Penny Nom lui répond.
Where will we use this in the real world? 2000-10-11
Jane Ann Musgrove pose la question :
As a teacher of mathematics, I am always asked "Where will we use this in the real world?". I am seeking ideas/sites via the internet where students can find answers to this type of question. Can you help me?

To be more specific, right now I am interested in finding careers where the employees would use the concepts of "Radicals", "Matrices", and "Logarithms". This information will be used by students to make presentations to the class on their findings from internet searches.


Harley Weston lui répond.
Larger and smaller 2000-10-10
Nicole pose la question :
which one of these arrows < , > points to the greater number? which arrows points to the smaller number.
Penny Nom lui répond.
The sum of the cubes is the square of the sum 2000-10-10
Otoniel pose la question :
Without using mathematical induction, or any other method discovered after 1010 a.d. , prove that the sum of i3, (where i, is the index of summation) from one to, n, is equal to ((n*(n+1))/2)2
Penny Nom lui répond.
Hendecagon 2000-10-09
Jillian pose la question :
I need an example of a object that is in the shape of a hendecagon. I know what the shape is but I cannot come up with a real life example of an object that is this shape.
Chris Fisher lui répond.
Sunflower seeds 2000-10-09
A parent pose la question :
Find the number of 3/4 pound of sunflower seeds that can be filled with 225 pounds of sunflower seeds
Penny Nom lui répond.
Independent tests 2000-10-07
A student pose la question :
If the false-positive rate of each test in a battery of tests is 0.05, how many independent tests can be included in the battery if we want the probability of obtaining at least one false-positive result to be at most 0.2?
Harley Weston lui répond.
Repeating decimals 2000-10-06
Mary O'Sullivan pose la question :
I understand that with repeating decimals (those with a pattern), the number of digits repeated is put into fraction form with the same number of 9's

ex. 0.4444 = 4/9 0.145145145 = 145/999

How can I explain why this is so? Some inquisitive 8th graders are anxious to find out!
Penny Nom and Walter Whiteley lui répond.

Cutting the cake 2000-10-05
Cherie pose la question :
How can you divide a cake (circle) into 14 pieces by using only 4 straight lines?
Penny Nom lui répond.
Pillows and Cushions 2000-09-27
Fiona pose la question :

The following problem was given to grade eleven algebra students as a homework assignment. To manufacture cushions and pillows, a firm uses two machines A and B. The time required on each machine is shown. Machine A is available for one full shift of 9.6 hours. Machine B is available for parts of two shifts for a total of 10.5 hours each day.
Harley Weston lui répond.

Isolating an exponent 2000-09-24
C. Scott pose la question :
Suppose you invest $500.00 in an account that pays 10% interest compounded annually. How long will it take for this value to triple?

A=p(1 + i)a A=1500 i=0.1
1500=500(1.1)a p=500 a=unknown

How do you solve this problem algebraicly? How do you isolate the variable (a) when it is an exponent?


Harley Weston lui répond.
Maclaurin series again 2000-09-23
Jason Rasmussen pose la question :
I suppose my confusion comes into play when I am trying to figure out where the xn term comes from. I know that the Power Series notation is directly related to the Geometric Series of the form sigma [ brn ] where the limit is b/(1-r) for convergence at | r | <1. Therefore, the function f(x) needs to somehow take the form of b/(1-(x-a)), which may take some manipulation, and by setting r = (x-a) and b = Cn, we get the Geometric Series converted to the Power Series. Taking the nth order derivative of the Power Series gives Cn = fn(a)/n!. There must be a gap in my knowledge somewhere because I cannot seem to make f(x) = ex take the form of f(x) = b/(1-(x-a)). Maybe I should have labelled my question as "middle" because it may be more of a personal problem with algebra and logarithms. Or, am I to assume that all functions can be represented by sigma [fn(a) * (x-a)n / n!]?
Harley Weston lui répond.
BEDMAS 2000-09-22
Monica Zimmer pose la question :
In the Math rule BEDMAS does it matter if you do the division or the multiplication first?
Penny Nom lui répond.
Mode 2000-09-22
James Barton pose la question :
I have always been told that a mode is the "one" number that appears most in the set of numbers: ex.{1,3,4,6,3,2} the mode is 3. What if you have {1,1,3,4,5,5}is there a mode. I was taught long ago that there is no mode, Not i am having to teach there is two modes. 1 and 5. If this is the case if we have {1,1,2,2,3,3,4,4,5,5} that every number is the mode. True or false. This is being ambigiuous if we say all are the mode. Because no one number is used more than the others.
Claue Tardif and Harley Weston lui répond.
Permutations and Multiplication Principle 2000-09-22
Candice pose la question :
A forester selects 4 pink and 4 white dogwoods. The trees are to be planted in row. If a tree is distinguished by color only, in how many ways can the eight dogwoods be planted? How many of these arrangements have at least two trees of the same color side by side?
Denis Hanson and Claude Tardif lui répond.
Dividing a region in half 2000-09-21
Kerry pose la question :
There is a line through the origin that divides the region bounded by the parabola y=x-x2 and the x-axis into two regions with equal area. What is the slope of the line?
Penny Nom lui répond.
A Maclaurin series 2000-09-21
Jason Rasmussen pose la question :
I have a question regarding power series notation for certain functions within the interval of convergence.
Harley Weston lui répond.
Leap Year 2000-09-20
Jennifer pose la question :
The earth revolves around the sun in 365.24 days. How does our calendar deals with the extra 0.24 day?
Penny Nom lui répond.
A cycloid in Cartesian form 2000-09-20
Billy pose la question :
The parametric equation of cycloid is given:
x=r(t-sint)
y=r(1-cost)

How to eliminate t?


Harley Weston lui répond.
Arithmetic in base 5 2000-09-20
Lesley Emerson pose la question :
my daughter is 9 and has been aske to solve the following in base 5

3+2
4+10
.
.
.
Penny Nom lui répond.

A proof that 1=2 2000-09-19
sporky pose la question :
Why does the proof for 1=2 not work?

x = 1
x2 = 1
x = x2
1 = 2x (derivitive)
1 = 2(1)
1 = 2 ???

please tell me where the false logic is.


Walter Whiteley lui répond.
Order of operations 2000-09-19
Nicole pose la question :
the problem is, 4x8-18 divided by 6= do you solve this by doing 4x8=32 then by dividing 18by 6= 3, then subtracting 3 from 32 = 29? If not what is the order of operation?
Penny Nom lui répond.
Circular Permutations 2000-09-18
J. Stuart pose la question :
I am able to understand the simple theory behind circular permutations (that is, there are (n-1)! ways to arrange n people in a circle. One question, however, is giving me some difficulty. It reads: In how many ways can four married couples be arranged around a circular table if each man must sit beside his wife? Any suggestions you have would be greatly appreaciated.
Penny Nom lui répond.
Buying art supplies 2000-09-18
Travis pose la question :
An art teacher buys exactly 100 items at this sale, and the total cost before tax is $100. She buys at least one of each item. How many of each item does she buy?

Markers $0.50
Sketch Pads $3.00
Paint Sets $10.00


Denis Hanson lui répond.
Probability of a square 2000-09-18
Nick pose la question :
What is the probability that four different points chosen at random from the fifteen equally-spaced points shown are the vertices of a square? I need to have my answer expressed as a common fraction. Help! I don't know how to write it.

 . . . . . . . . . . . . . . . 

Penny Nom lui répond.
Review problems 2000-09-18
Dee pose la question :
A card is selected from an ordinary deck of cards. What is the probability of. . . selecting 2 aces in a row?

If you toss two dice, what would be your probability of the following?
.
.
.


Penny Nom lui répond.
Mr. Edgecomb's math exam 2000-09-17
Rachel pose la question :
In Mr. Edgecomb's math class, 30 students took an exam on statistics. If the average passing grade was 84, the average failing grade was 60, and the overall average was 80, how many students passed the test?
Penny Nom lui répond.
Tessellations 2000-09-17
Lindsay pose la question :
What is the word that means a shape repeated over and over again to make something like a quilt pattern?

Note: I'm pretty sure it is either a fractal or tesselation. Could it be that the pattern itself is a fractal but the entire quilt would be a tesselation?


Chris Fisher lui répond.
1234567890 2000-09-14
Bradley Kloetzly pose la question :
Can you find two whole numbers, with the smallest possible difference between them, which when multipled together equal: 1234567890?
Harley Weston lui répond.
6-49 2000-09-14
Steve pose la question :
In our state lottery you must choose 6 numbers (1-49). How many different combinations are there? They can be in any order.
Harley Weston lui répond.
Rounding 2000-09-14
MaryAnn pose la question :
How many whole numbers rounded to the hundreds place, round to 400? Can you also explain why?
Penny Nom lui répond.
Two linear equations 2000-09-14
David Dean pose la question :
2a + 1b = 3.39 3a + 3b = 6.59
What formula do I use to find what a = ?

Harley Weston lui répond.
The smaller of a and b 2000-09-14
Jenna pose la question :
For any two real numbers, a and b, give a mathematical expression in terms of a and b that will yield the smaller of the two numbers. Your expression should work regardless of whether a>b, a
Penny Nom lui répond.
Rational Numbers 2000-09-14
Josh Kuhar pose la question :
How can you tell a number is rational?
Harley Weston lui répond.
1 + 2 + 3 + ... + 50 2000-09-14
Vicki Charron pose la question :
How can you calculate the total of the numbers one through fifty, without adding up the individual numbers?
Penny Nom lui répond.
7 - - - - 77 2000-09-13
Peter pose la question :
Does anyone know how to solve the following:
7 _ _ _ _ 77 ?

I have to find the missing values.


Chris Fisher and Walter Whiteley lui répond.
4-digit numbers using 7, 8, 9 and 0 2000-09-13
Ryan pose la question :
Could you please help me with the following problem, How many different 4-digit numbers are there that use each of the digits 7,8,9,and 0? Please list them.
Penny Nom lui répond.
Manipulating powers 2000-09-13
Phil pose la question :
21/5 x 42/5 = ?
Penny Nom lui répond.
Flim 2000-09-12
Jodi and Ari pose la question :
Can you tell us the definition of the word FLIM? My daughter is in 4th grade, and this came up. Could not find it in the Websters Dictionary.
Chris Fisher lui répond.
Selling chickens 2000-09-12
Rick pose la question :
A man raised chickens. He sold all but 8 of them. The first buyer bought 1/3 of all the chickens + 2/3 of a single chicken. The second buyer bought 1/3 of the remaining chickens + 1/3 of a single chicken. The third buyer bought 1/3 of the remainder + 2/3 of a chicken. How many chickens did the seller own before selling any? All chickens were alive and whole when the buyers received them.
Penny Nom lui répond.
Logs and trig functions 2000-09-12
Becky pose la question :
How do they get these answers?
  1. log 8 + log 2 = ?
    Answer is: log 16

  2. For 0 degree < x < 90 degree, how many solutions are there for the equation 2sin x = cos x?
    Answer: 1


Penny Nom lui répond.
Factoring 2000-09-12
Melissa pose la question :
I would like you to help me factor (x 6-y 6) & (a+b)2+3(a+b)-4
Penny Nom lui répond.
Two geometry problems 2000-09-09
Becky pose la question :
What are all the real values of x that are solutions for the inequality [x-2] < 6? ( it's less than or equal to)

What is the distance between the points with (x,y) coordinates (3,-2) and (-3,-1)?


Peny Nom lui répond.
Induction 2000-09-07
Joe Peterson pose la question :
How do I prove by the principal of mathematical induction?
1.n+2.(n-1)+3.(n-2)+.....+(n-2).3+(n-1).2+n.1=(n(n+1)(n+2))/6

Paul Betts lui répond.
How many 17's and 19's total 1000? 2000-09-07
Jonathan pose la question :
My question is: what 2 numbers would multiply 17 and 19 for a total of 1000. The numbers should not contain any decimal.
Penny Nom lui répond.
Roots of x^2 + 22 x + 112 2000-09-07
Brian R. pose la question :
I need to find the root of the quadratic equation of a square. The problem is x2 + 22x + 112 = 0.
Penny Nom lui répond.
Trinomial 2000-09-06
Lea pose la question :
I need to find the trinomial value of k which makes a perfect square. The problem is x2 - 6x + k
Penny Nom lui répond.
Derivatives, there must be an easier way 2000-09-06
Brad Goorman pose la question :
The direction read: Take the derivative of each expression.

y = {1+[x+(x2 +x3)4]5}6


Harley Weston lui répond.
Euclidean distance 2000-09-06
Velma Zahirovic-Herbert pose la question :
If d(x,y) is euclidean distance between x and y Prove that
d(x,y)>=0
if d(x,y)=0 than x=y
and d(x,y)=d(y,x)

Paul Betts lui répond.
Gravity 2000-09-06
Robert Broomfield pose la question :
If they dropped a 1lb object from 40,000 feet in the air, at what speed would it it the ground?
Harley Weston lui répond.
n3 + 2n2 is a square 2000-09-04
David Xiao pose la question :
determine the smallest positive integers, n , which satisfies the equation

n3 + 2n2 = b

where b is the square of an odd integer


Harley Weston lui répond.
Making milkshakes 2000-09-04
Linda pose la question :
To make a chocolate milkshake, 3 parts chocolate syrup are mixed with 2 parts malt. To make a vanilla milkshake, 2 parts vanilla syrup are mixed with 1 part malt. If equal parts chocolate and vanilla milkshakes are mixed, what is the proportion of malt to milkshake?
Penny Nom lui répond.
A equation with a square root 2000-09-03
Lea pose la question :
Please help with 2 plus the square root ( and under it has x plus 1) = 6
Thank you

Penny Nom lui répond.
Inequalities 2000-09-02
Jennifer pose la question :
I would like some help with equations and inequalities. My first inequality is 3p-6>21 and 3q+11+8q>99.
Paul Betts lui répond.
A number problem 2000-09-02
Lalita Balu pose la question :
Can you arrange 1234567890 to add up to 100?
Penny Nom lui répond.
Trigonometry 2000-09-02
david pose la question :
determine the sum of the angles A,B where 0 <= A , B <= 180 (degrees)

sinA + sinB = sqr(3/2) , cosA + cosB = sqr(1/2)


Chris Fisher lui répond.
How many planes contain a line and a point? 2000-08-30
Harold pose la question :
How many planes contain each line and point?
Harley Weston lui répond.
Adriana's earnings 2000-08-28
Adriana pose la question :
On Friday Adriana earns half as much as she did on Thursday. On Saturday she earns twice as much as she did on Thursday, if her total for 3 days is $63.00 how much did she earn each day?
Penny Nom lui répond.
Velocity of a pendulum 2000-08-28
Mekca pose la question :
A pendulum hangs from the ceiling. as the pendulum swings, its distance,d cm, form one wall of the room depends on the number of seconds,t, since it was set in motion. assume that the equation for d as a function of t is: d=80+30cos3.14/3t, t>0.

estimate the instantaneous rate of change of d at t=5 by finding the average rates for t=5 to 5.1, t=5 to 5.01, and t=5 to 5.001.


Harley Weston lui répond.
Solving an equation 2000-08-26
Patrick pose la question :
My question is how would u do a problem like this..........
[2x-37] =15?....u have to solve it for absolute value equations....????

Harley Weston lui répond.
Cubic yards and cubic feet 2000-08-26
Rhonda pose la question :
have 2.47 cubic yards. what could the dimensions, in feet, be to equal this?
Penny Nom lui répond.
Subtracting fractions 2000-08-26
Sarah Stanczyk pose la question :
how is this problem solved??

3/ x+1 - 5/x
( 3 divided by x +1 subtracted by 5 divided by x)


Penny Nom lui répond.
The sum of the squares of 13 consecutive positive integers 2000-08-25
Wallace pose la question :
Prove that it is not possible to have the sum of the squares of 13 consecutive positive integers be a square.
Harley Weston lui répond.
Three points on a line 2000-08-25
Casey pose la question :
I am trying to find the slope and y-intercept of an equation. I have THREE x values and THREE y values. How do you do it? Help!
Penny Nom lui répond.
Three pattern questions 2000-08-22
Michael Rodriguez pose la question :
I have 3 pattern questions that I need help answering, please.
  1. 6 and 7 = 42
    2 and 5 = 10
    4 and 8 = 8
    5 and 9 = ?

  2. 7 and 5 = 1
    9 and 12 = 3
    10 and 15 = 5
    12 and 16 = ?

  3. 1st = 1
    3rd = DEF
    10th = *
    6th = ?


Claude Tardif lui répond.
Covering 1, 1/2, 1/3,... 2000-08-22
Wallace pose la question :
Consider the points 1, 1/2, 1/3, ... on the real number line. You are given five small bars, all of length p, which are to be placed on the number line such that all points will be covered. What is the minimum value of p that will allow you to do this?
Penny Nom lui répond.
Slope 2000-08-19
John K. DePonte pose la question :
My question is to why the variable "m" was chosen to represent the slope of a linear equation. I always told my class to think of "m" for "m"ountain slope. But what is the real reason for this?
Penny Nom lui répond.
Six typists 2000-08-19
Paula Duncan pose la question :
If it takes a typist 4.5 hours to type 860 words, how many hours would it take 6 typist to do 16800 words?
Penny Nom lui répond.
Three consecutive odd integers 2000-08-18
Wallace pose la question :
A six-digit integer XYXYXY, where X and Y are digits is equal to five times the product of three consecutive odd integers. Determine these three odd integers.
Paul Betts lui répond.
Two word problems 2000-08-16
Bridget pose la question :
A whale's head is 72 inches long... its tail is as long as its head plus half the length of its body, and its body is half the entire length. How long is the whale?

Also, An author published a book every two years. When the seventh one was published, the sum of the years of publication was 13,804. In what year was the author forst published?


Penny Nom lui répond.
Find the next term 2000-08-12
Ashley pose la question :
8,27,64
I need the next three numbers & I can't figure it out. I have worked on this all day.

Penny Nom lui répond.
Some trigonometry 2000-08-11
Angela pose la question :
I have some PreCal questions. I am a student at the secondary level. I would be very grateful for your help.

Solve the equation for theta (0 <= theta < 2pi).

tan2(theta) = 3 I know sec2(theta) -1 = tan2(theta)

.
.
.
Harley Weston lui répond.

A problem with a quadratic 2000-08-09
David Xiao pose la question :
Find the value of a such that 4x2 + 4(a-2)x - 8a2 + 14a + 31 = 0 has real roots whose sum of squares is minimum.
Harley Weston lui répond.
PreCalculus 2000-08-09
Angela pose la question :
Use absolute values to define the interval or pair of intervals on the real line.

 
<--|--- |--- ]--- |--- |--- |--- [---| ---|-->    
   18  19  20  21  22  23  24  25  26    

A car is moving at the rate of 50 miles per hour, and the diameter of its wheels is 2.5 feet.
a) Find the number of revolutions per minute that the wheels are rotating.
b) Find the angular speed of the wheels in radians per minute.


Harley Weston lui répond.
The angle of rotation 2000-08-03
Jay pose la question :
I have the following information Given.

(X1, Y1) Origional Point
(X2, Y2) Origional Point After a Rotation
(Xa, Xb) Center of Rotation

What formula would I use to figure out the angle the point was rotated?


Chris Fisher and Harley Weston lui répond.
Area of a circle 2000-08-03
Larry pose la question :
I know the formula is-- pi r squared--. For a circle 4 inches in diameter, do I multiply pi (3.1416) by the radius (2") then square the answer to that ie: 3.1416 X 2 squared or do I square the radius (2 X 2") then multiply by pi (3.1416) ??
Penny Nom lui répond.
Graphing an inequality 2000-08-02
Lori pose la question :
How do I find x and y and graph this problem

3x + y < 5


Penny Nom lui répond.
Two linear systems 2000-08-01
A student pose la question :
please help me with this homework question. 5/x + 6/y= 19/6 3/x + 4/y =2
hint: let a = 1/x and b = 1/y substitute these expressions into the system to find a and b. Then find x and y.

This is a question I answered wrong on a test: solve the given system for x, y, and z. Express your solutions in terms of a, b, and c.


Penny Nom lui répond.
Making a paper cone 2000-07-30
John pose la question :
The question of how to lay out & cut out of paper, cones came up. I would like the cone have :
A base of 4 inches
and height of
4 inches,
6 inches,
8 inches.

Harley Weston lui répond.
The circumference of a circle 2000-07-30
Not a student pose la question :
An equalateral triangle is enclosed in a circle. The three corners touch the edges of the circle. One side of the triangle is 12. What is the circumference of the circle?
Penny Nom lui répond.
A semi-circle and a triangle 2000-07-28
Ben pose la question :
A semi-circle and an isosceles triangle ABC have the same base AB and the same area. The equal angles in the triangle are BAC and CAB. I have to find the value of each of these angles.
Harley Weston lui répond.
LOG(LN(x)) = 1 2000-07-28
An algebra student pose la question :
LET F(x)=LOG X AND G(x)= LN X. SOLVE (f *G)(x)= 1
SHOW COMPOSITION AND USE DEFINITION OF LOGS.

Harley Weston lui répond.
(mn + m + n)/(m^2 + n^2) = 1 2000-07-24
William pose la question :
Find all pair of positive integers m and n such that mn + m + n divides m2 + n2 = 1.
Peny Nom lui répond.
An equation involving x to the x 2000-07-22
Joy Peter pose la question :
I am joy, a teacher teaching Maths at the secondary level and while solving a sum came to this stage when i got xx (1 + log x) = 0, by which we can conclude that xx = 0 or 1 + log x = 0. If xx = 0, than what should be the value of x? I feel that the value of x should then be 0 (zero) but then how do I explain this to the students as we also know that anything to the power of 0 is 1 but here 0 raised to 0 is 1. If this is not defined then how do I explain this?
Penny Nom lui répond.
n! = 42(n-2)! 2000-07-21
Damon Bailey pose la question :
Solve n! = 42(n-2)!
Paul Betts lui répond.
10,000! 2000-07-21
Lauren pose la question :
Hi I was just wondering if you could tell me how many zeros are in 100,000! (factorial.)
Denis Hanson lui répond.
L'Hospital's Rule 2000-07-19
Dan Krymkowski pose la question :
The limit of the following as x goes to infinity is 2*y. Y is a constant.

lim 2*x*log(x/(x-y)) = 2*y


Harley Weston lui répond.
Completing a square 2000-07-10
Lexa Michaels pose la question :
How do you complete a square? the textbook question is: x 4 + 64
Penny Nom lui répond.
Patterning and Sequencing 2000-07-05
Michael Jellis pose la question :
What would be the next two terms?

1.0,0.5,0.6,0.75,0.8,___,____

please explain!!! I am completely baffled and need all the help I can get!


Claude Tardif lui répond.
Five times a cube equals three times a fifth power 2000-07-05
Harman Chaudhry pose la question :
Which is the smallest 10-digit number to be five times the cube of one number and also three times the fifth power of another?
Penny Nom lui répond.
Word addition 2000-07-05
Harman Chaudhry pose la question :
What is the value of DISHES if SEE + THE + WAITER + WASHES = DISHES. In addition, I know there is a name for these types of problems--what are they actually called?
Chris Fisher lui répond.
Simplify 21+2[3z+5(3z+8)] 2000-07-02
Dennis Dyer pose la question :
My daughter has a math problem that I can't help her with. The problem is 21+2[3z+5(3z+8)] I can get the answer 101 +36z but I can't show her the correct way to write it out. Would you please show the correct way to show her work...
Penny Nom lui répond.
A trig question 2000-07-01
Will pose la question :
An open rectangular tank a units deep and b units wide holds water and is tilted so that the base BC makes an angle theta with the horizontal. When BC is returned to the horizontal, who that the depth of the water is

(a squared) * cot theta div 2b units


Harley Weston lui répond.
Parallel tangents 2000-06-30
Ebony Indalecio pose la question :
I need to prove the theroem: Tangents to a circle at the end points of a diameter are parallel.
Walter Whiteley lui répond.
Tiling a floor 2000-06-27
Carolyn Clarkston pose la question :
A square tile measures 6 inches by 6 inches. What is the least number of tiles needed to cover a rectangular floor area of 9 feet by 12 feet?
Walter Whiteley lui répond.
Calculator and telephones keypads phones 2000-06-27
Thomas Smith and Veronica Yates-Riley pose la question :
On a keyboard, why is the number "7" on the top of the keypad as opposed to the number "1" at the top a telephone keypad?
Penny Nom lui répond.
An Area 2000-06-26
Frank pose la question :
Can you tell me what the sq. ft. are of and area measuring:
            __________58____________
           |                       | 
            |                      |  
             |                     |    
              |                    |    
               |                   |   
             76 |            70    |       
                 |                 |        
                  |                |        
                  |_____21________ | 

Harley Weston lui répond.
Central Limit Theorem and Law of Large Numbers 2000-06-26
Jonathan Yam pose la question :
The Central limit Theorem states that when sample size tends to infinity, the sample mean will be normally distributed. The Law of Large Number states that when sample size tends to infinity, the sample mean equals to population mean. Is the two statements contradictory?
Paul Betts and Harley Weston lui répond.
Cascade 2000-06-22
Peter Bengtsson pose la question :
Can you help me find an equation for this correlation?

2*1+1
3*2+0
4*2+2
5*3+0
6*3+3
7*4+0
8*4+4
9*5+0
10*5+5

This is the way scores are calculated when you play the game Cascade. The more number of balls you manage to "click away", the better score you get. So, I wrote down lots of results for different amount of balls I clicked away. Clicking away one pair (two adjacent) of balls means 3 points. Clicking away three adjacent balls means 6 points. etc. You can see this from the list above.

What I now want to do is to find an equation with only ONE unknown! Y= kn*X+c or something. Whereby I only know X, I can find Y.


Penny Nom lui répond.
A bar over a Roman numeral 2000-06-21
Charles Fontaine pose la question :
Is there any significance to the bar placed over some Roman numerals?
Penny Nom lui répond.
Cairo tesselation and Archimedean duals 2000-06-21
Joyce DuVall pose la question :
I am looking for a picture of the Cairo tesselation, and pictures of the Archimedean duals. Do you know of any good web sites or books?
Penny Nom lui répond.
Lines on an oscilloscope screen 2000-06-20
Janis Watson pose la question :
What are the proper names for the vertical and horizontal lines on a graph? I am trying to explain an oscilloscope screen, and I don't know what to call these, except "vertical lines" and "horizontal lines."
Penny Nom lui répond.
The speed of light 2000-06-19
Benny Lau pose la question :
I have a personal questions. In physics,if a person is running on a train, his relative speed on the ground will be the addition of the speed of train and the person. If u have a train inside another train and inside another train, so on...... can u reach the speed of light? It would need a very long distance. But if we make all the train travel in circles. Then we don't need that much distance. So can we achieve the speed of Light?
Robert Coleman and Harley Weston lui répond.
Numerator and denominator 2000-06-18
Maureen Beard pose la question :
What is the origin of the terms numerator and denominater?
Penny Nom lui répond.
Names for large numbers 2000-06-16
Mireille Carthier pose la question :
I am trying to find the common names (in English and French) for the big numbers as follows:
English French
106 million million
109 billion milliard?
1012 trillion billion?
1015 ?? trillion?

Thank you very much


Claude Tardif and Harley Weston lui répond.
A sequence 2000-06-16
Claire Hall pose la question :
Can you find the formula for the pattern 4,12,24,40,60
AClaude Tardif lui répond.
Simplifing 2000-06-15
Angie Herbert pose la question :
My daughter is having problems with her algebra homework. She is a year 7 pupil at high school in the UK. She has been given homework on simplifying formulae and she doesn't understand how to do them. Here is an example of one of the questions :

9s+7t+5c+5s-3t

can you help her to understand how to do these and perhaps me too.
Penny Nom and Claude Tardif lui répond.

A percentage question 2000-06-15
Michael Smith pose la question :
I need a percentage for a business plan. How much is one-percent of two-hundred and thirty-nine million?
Penny Nom lui répond.
Rectangles and algebra 2000-06-13
Kirstin pose la question :
A rectangle's length is 4 more than twice its width. The area of the rectangle is 336m squared. What is its length?
Paul Betts and Penny Nom lui répond.
Two problems 2000-06-12
Sharon pose la question :
If f(4)=0 and f(6)=6, which of the following could represent f (x)?

A. 2/3x-4 B. x+2 C. x-4 D. 3/2x+6 E. 3x-12

these are problems to study for a test so I need to know the answer and how it was solved!

I have one more question

If 180o < theta < 270o and tan theta = 4/3, then sin theta =?

A. 5/4 B. -4/5 C. 3/5 D. 12/5 E. -3/5


Harley Weston lui répond.
Projecting a line segment onto a plane 2000-06-08
Monica pose la question :
What is the measure of the angle determined by a 14 inch segment and its projection into a plane if the length,in inches, of the projection into the plane is 7 inches?
Penny Nom lui répond.
Surface area of a contact lens 2000-06-06
Evie Contreras pose la question :
I would like to know how to calculate the surface area of a contact lens with a radius of 7mm? I know that the area of a circle is pi R squared, but a contact lens has a dome.
Harley Weston lui répond.
8 Queens on a Chess Board 2000-06-06
Patrick McGarrity pose la question :
In the classic puzzle where you put 8 Queens on a chess board and no queen can take any other queen, I was wondering if there was multiple solutions. Obviously there's the mirror and opposite images of the way I solved it, but I was wondering how many solutions there were, and if these solutions all followed a similar pattern?
Claude Tardif lui répond.
Divisors of 2000 2000-06-06
Amanda Semi pose la question :
  1. find the product of all the divisors of 2000
  2. dog trainer time has 100m of fencing to enclose a rectangular exercise yard. One side of the yard can include all or part of one side of his building. iff the side of his building is 30 m, determine the maximum area he can enclose

Claude Tardif lui répond.
Problems 2000-06-06
Debbie Cummins pose la question :
I am a Mum of a 12 yr.boy needing help with some math problems. I need not only the answers but how it is worked out.
  1. Both the leftmost digit & the rightmost digit of a 4 digit number N are equal to 1. When these digits are removed, the 2 digit number thus obtained is N div by 21 Find N.
  2. Find all 3 digit even numbers N such that 693xN is a perfect square, that is, 693x N = k x k where k is an integer.
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Paul Betts and Claude Tardif lui répond.
Writing in Math 2000-06-05
Laurel pose la question :
How can I incorporate writing into my math curriculum?
Penny Nom lui répond.
A derivative problem 2000-06-04
Jeff Ellis pose la question :
If F(x)=(4+x)(3+2x2)2(2+3x3)3, find F'(0)
Harley Weston lui répond.
Percents with mixed numbers 2000-06-04
Julie pose la question :
How would you find the percent of 33 1/3 out of 90 by using fraction settup!I can do whole numbers but not mixed. This is how to do whole numbers say it was 33 of 90

33 x 90 = 2970
100 x 1 = 100
2970 divided by 100
the answer is 29.7

so how do you do it with a mixed number


Penny Nom lui répond.
Pi to 5 decimal places 2000-06-03
Emily pose la question :
The question is find the value for pi to 5 decimal places????
Penny Nom lui répond.
A centroid problem 2000-06-02
Kerstin pose la question :
An isoceles triangle has sides measuring 13 cm, 13 cm, and 10 cm. Find the distance from the centroid to the vertex of a base angle.
Harley Weston lui répond.
4 Color map Theorem 2000-06-02
Rick Slen pose la question :
I am challenging my students to find a map that can not be coloured using only 4 colours. I know that it is not possible, but one boy drew a map with a "country" totally surrounding all the others so of course it touched all other colours. How do I explain that this type of map is not permissable?
Denis Hanson lui répond.
1+4+9+16+...n^2 = n(n+1)(2n+1)/6 2000-06-01
Shamus O'Toole pose la question :
How do you derive that for the series 1+4+9+16+25.. that

S(n)=(n(n+1)(2n+1))/6


Penny Nom lui répond.
Using the inverse sine function 2000-05-31
Nelson Rothermel pose la question :
This has me completely baffled. I have to use the laws of sine or cosine to find the angles of a triangle when I have 3 sides, so I can't go 180-x-y when I have 2 angles. Now, I have a triangle with values of 3, 7, and 9. Here are the steps I used (A,B,C are angles; a,b,c are opposite sides):

angle A (16.1951 degrees): cos-1*((b2+c2-a2)/(2*b*c))
angle B (40.6011 degrees): sin-1*(b*sin(A)/a)
angle C (56.7962 degrees): sin-1*(c*sin(A)/a)

If you notice, A+B+C does not equal 180. According to the book, A and B are correct, but C is supposed to be 123.2038 degrees. Why doesn't it work???


Harley Weston lui répond.
Powers of i 2000-05-24
Paul Fieldhouse pose la question :
What is the result of raising i to the googol power? is there a rule or pattern to raising i by increasing powers of 10?
Penny Nom lui répond.
Why does division start from the left? 2000-05-24
Salil Dave pose la question :
Addition, subtraction and multiplications start with right most digit and proceed left, but division starts from left-most digits and goes right ... why?
Harley Weston lui répond.
A 100-gon 2000-05-24
Chris Mohr pose la question :
What is a 100-gon called?
Harley Weston lui répond.
Angular velocity 2000-05-24
Ashley Milliman pose la question :
The crankshaft of a particular automobile engine has an angular velocity of 1,500 rpm at 30 mph. The crankshaft pulley has a diameter of 10 cm, and it's attached to an air conditioner compressor pulley with a 7 cm diameter and an alternator pulley with a 5 cm diamter

At what angular velocities do the compressor and alternator turn?

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Harley Weston lui répond.
The equation of a parabola 2000-05-22
Ian Forsyth pose la question :
Given the points A(0,0) B(60,10) C(24,d) find the equation of the parabola. leave the equation in terms of x, y and d if the general form of a quadratic is y = ax2 + bx + c.
Penny Nom lui répond.
Calculus Research Questions 2000-05-22
William Wright pose la question :
I am a Calculus Teacher, and me and my class ran into these two problems without solutions in my manual, we got answers, but are unable to check them. If anyone gets this email and can respond to this with the solutions it be greatly appreciated.
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Harley Weston lui répond.
Adjacent Angles 2000-05-21
Katherine Keys pose la question :
Can a straight angle be an adjacent angle to another angle?
Chris Fisher lui répond.
Volume of a sphere 2000-05-21
Kevin Partridge pose la question :
Does anyone have a way to physically demonstrate how to explain the volume formula for a sphere? Or perhaps how to derive the formula without calculus?
Harley Weston lui répond.
The pythagorean theorem 2000-05-19
Lauren Fitzgerald pose la question :
how do you find the length of th hipotnuse( or however you spell that word). i understand you have to add the two sides. but when i do add i always end up with this way off answer. i donot understand at all.
Paul Betts lui répond.
The square root of -1 2000-05-19
Gary pose la question :
i am not a student i am just some one that heard something and i can't be sure on the answer...my ? is what is the square root of -1? i think it is -1 but not sure can you let me know please thank you
Harley Weston lui répond.
A conic in standard form 2000-05-18
Tara McConkey pose la question :
Im havign trouble converting the following conic to standard form, i know that the conic is a hyperbola but that is all 16x2-9y2-160x-18y+247=0
Harley Weston lui répond.
Radioactive decay 2000-05-18
Catherine Sullivan pose la question :
Please help me with the following: The radioactive isotope carbon-14 is present in small quantities in all life forms, and it is constantly replenished until the organism dies, after which it decays to carbon-12 at a rate proportional to the amount of C-14 present, with a half life of 5730 years. Suppose C(t) is the amount of C-14 at time t.
  1. Find the value of the constant k in the differential equation: C'=-kC
  2. In 1988 3 teams of scientists found that the Shroud of Turin, which was reputed to be the burial cloth of Jesus, contained 91% of the amount of C-14 contained in freshly made cloth of the same material. How old is the Shroud according to the data?

Harley Weston lui répond.
Graphing a linear function 2000-05-17
Chelsea pose la question :
I need help with grahing linear functions.If you could e-mail me back the basics and how tos I would be much appriciative.
Penny Nom lui répond.
The number of seats in an auditorium 2000-05-16
David Evaska pose la question :
There are 10 students in the first row of seats in an auditorium 12 in the second 14 in the third and 2 additional in each seat. The total number of rows is 40. I know the answer is 1960 can you please show me the formula step by step.
Penny Nom lui répond.
Six letter words 2000-05-15
Karl Freitag pose la question :
An anthroplogist discovers an isolated tribe whose written alphabet contains only six letters (call the letters A,B,C,D,E, and F). The tribe has a taboo against using the same letter twice in the same word. It is never done. If each different sequence of letters constitutes a different word in the language, what is the maximum number of six-letter words that the language can employ?
Penny Nom lui répond.
A trigonmetric identity 2000-05-15
Caitlin pose la question :
My name is Caitlin and my question is from 11th grade math and I'm a student

my question is I need to solve this identity :

cos x csc x - sin x sec x = 2 cot 2x


Paul Betts lui répond.
Multiplying fractions 2000-05-14
A student pose la question :
75/2 x 1/100 = 3/8

Please show how to came up with the answer?
Penny Nom lui répond.

A matrix equation 2000-05-14
A student pose la question :
Right now, we are dealing with matrices and we are supposed to solve the following problem on our graphing-calculators: 2a+3b-4c+d=20
a-2b+3c-5d=-14
3a+4b-2c+3d=19
5a-b+6c+4d=-5

Penny Nom lui répond.
Subtracting polynomials 2000-05-13
Teresa pose la question :
I am suppose to subtract the lower polynomial from the one above it.
-3a+11b+2f
-3a- 6b+8f
________________

Penny Nom lui répond.
4x - [2x -(3x - 2)] = 13 2000-05-13
Teresa pose la question :
I need to find the following equation.
4x - [2x -(3x - 2)] = 13

Penny Nom lui répond.
Reflection off a sphere 2000-05-12
Mark Adami pose la question :
Given two points P,E and a sphere. Find a point on the sphere, T, so that a line from P that bounces off the sphere at T goes through point E.
Chris Fisher and Harley Weston lui répond.
Solve 2sin 3x-1=0 2000-05-11
Cynthia pose la question :
How would you solve 2sin 3x-1=0? I don't know what to do with the 3.
Penny Nom lui répond.
The units digit of 3 to the 58th power 2000-05-10
Kylie Mcalpine pose la question :
the questions we have been asked are what is the units digit of the following:

a) 358
b) 2358
c) 1731

and the harder question of:

what is the units digit of the following sum: 13841 + 17508 + 24617 = ???????


Paul Betts and Penny Nom lui répond.
Odds and combinations 2000-05-10
Lucy pose la question :
If the odds are 1/15 of winning, what is the probability?

if c 5! 3! How does it equal 10?


Harley Weston lui répond.
The Village of Truth 2000-05-10
Sean Pearson pose la question :
Our teacher gave us a logic problem involving two villages: the village of truth, and the village of lies. The problem is in asking two guards the right question to gain entrance to the fenced compound the villages are in without being shot. Have you heard of this problem ?
Harley Weston lui répond.
Trig functions 2000-05-09
Melissa pose la question :
Find all solutions in the interval (0,2pi)
2cos2x-3cosx-4=0

Paul Betts and Harley Weston lui répond.
Supplementary angles 2000-05-09
Suzanne pose la question :
We know that: Supplementary angles are two angles whose sum equals 180 degrees and complementary angles are two angles whose sum equals 90 degrees. Are supplementary and complementary angles necessarily adjacent? or can they be non-adjacent?
Chris Fisher lui répond.
Looking for a pattern 2000-05-08
Laura pose la question :
Yesterday, me teacher stumped me with a question. He talked to us about square units. He told us an area of 1 square unit produces 1 shape, an area of 2 sq.units produces 1 shape, an area of 3 sq.units produces 2 different shapes, an area of four square units produces 5 different shapes, and an area od five sq.units produces 12 different shapes. He left us there. He said we had to find how many different shapes an area of 1 sq. unit produces through how many different shapes an area of 15 sq.units produces. He said we could complete this "chart" by finding an equation. But, I can't find the equation. I think it may be a quadratic of some sort. My teacher told us to use the area(in sq.units) as X and the # of different shapes produced as Y. Now, what really is stumping me is I would have to have an equation so when X is Y, Y is 1 and when X is 2, Y is 1. I have also tried to see if I can complete a patter or something. The pattern I saw was 1,1,2,5,12. I can't make much sense of that pattern.
Penny Nom lui répond.
Parallel and perpendicular lines 2000-05-08
Jimmy Lumpkins pose la question :
Need a method for solving the following problem: Find the equation of a line through point P that is parallel or perpendicular to another line.
Paul Betts lui répond.
Related Rates 2000-05-07
Derek pose la question :
How can you show that if the volume of a balloon is decreasing at a rate proportional to its surface area, the radius of the balloon is shrinking at a constant rate.
Harley Weston lui répond.
Probability and odds 2000-05-05
Leah pose la question :
The chances of rain on friday, saturday, and sunday are 20%, 30%, and 50% respectively. what are the odds it will rain all three days?
Harley Weston lui répond.
Finding a formula 2000-05-05
Erica Hildebrandt pose la question :
If a farmer has a field and his plots are laid out in the following grid where each # represents a plot:
4 5 12 13 20
3 6 11 14 19
2 7 10 15 18
1 8 9 16 17

Of course the plot numbers aren't meaningful as I have described above. In fact they may not be numbers at all. The only constants I have are the total number of rows and columns. Using the total number of rows and columns and my current position row and column, how can I write a formula that tells me column 3 row 3 = 10, column 4 row 2 = 14, etc. I can see the pattern but can't quite get the formula. I believe I will need 2 different formulas one for even and one for odd rows.
Paul Betts and Penny Nom lui répond.

An improper integral 2000-05-04
A high school senior pose la question :
Hi, I am a high school senior and I need help stugying for a final. I am stuck on one of the questions on my review sheet. Does the improper integral from 5 to infinity of (38/97)x converge or diverge? If it converges I also need to know how to find the approximate value accurate to .01 of its actual value.
Harley Weston lui répond.
sin(7pi/12) 2000-05-04
Kristel pose la question :
What is the exact value of sin 7pi/12?
Chris Fisher and Paul Betts lui répond.
Thearcius Functionius 2000-05-03
Kevin Palmer pose la question :
With the Olympics fast approaching the networks are focusing in ona new and exciting runner from Greece. Thearcius Functionius has astounded the world with his speed. He has already established new world records in the 100 meter dash and looks to improve on those times at the 2000 Summer Olympics.

Thearcius Functionius stands a full 2 meters tall and the networks plan on placing a camera on the ground at some location after the finish line(in his lane) to film the history making run. The camera is set to film him from his knees(0.5 meters up from the ground) to 0.5 meters above his head at the instant he finishes the race. This is a total distance of two meters(the distance shown by the camera's lens).
Harley Weston lui répond.

An indefinite integral 2000-05-03
Bonnie Null pose la question :
I am to find the indefinite integral of: (ex - e-x)2 dx
Claude Tardif lui répond.
Mary Fairfax Greig Somerville 2000-05-03
Joshua Garrett pose la question :
I'm giving a report in class on her life. Could i recieve some sort of information about her. thank you
Claude Tardif lui répond.
Why is 1/4 larger than 1/5? 2000-05-02
Sherry pose la question :
I have to do a math project for my teacher education class. The question that I am working on is why is 1/4 bigger than 1/5.
Paul Betts, Claude Tardif and Penny Nom lui répond.
Minimizing the metal in a can 2000-05-02
May Thin Zar Han pose la question :
A can is to be made to hold 1 L of oil. Find the dimensions that will minimize the cost of the metal to manufacture the can.
Harley Weston lui répond.
Matrices Information 2000-05-02
William Avery pose la question :
I am an OAC student at Governor Simcoe Secondary School in St. Catharines Ontario. Today at school we were handed an independent study project by our Finite teacher. This assignment is based on Matrices, it involves performing some simple matrix calculations, but also involves a written section. This written section asks for the following:
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Marley Weston lui répond.
Area of an ellipse 2000-05-02
Kaushal Shah pose la question :
How do I Calculate the area of a ellipse known the length of any related thing. Example, suppose if I know the length of latus rectum, major&minor axis etc.
Walter Whiteley lui répond.
Two calculus problems 2000-05-01
Kaushal Shah pose la question :
How Do WE Integrate the following Functions,
  1. Integral xtanx dx
  2. How was natural base "e" discovered and why e=2.7.......

Claude Tardif lui répond.
Fractals 2000-04-29
Rachel Maginn pose la question :
What are Fractals? I am doing a research project. Any information would be great. I need to know the history behind fractals, and how they are used. I would like some examples like the snowflake and a fractal tree. Any other examples would be appriciated greatly.
Harley Weston lui répond.
What percent is one fraction of another fraction? 2000-04-29
A student in grade 4 pose la question :
What is the method for finding out what percent one fraction is of another fraction. For instance 4/5 is what percent of 1/9?
Penny Nom lui répond.
Monica's geometry problem 2000-04-27
Monica pose la question :
Given: ABCD is a square; AX is perpendicular to BY
Prove: Angle 1 is congruent to Angle 3

Chris Fisher lui répond.
Graphing cube roots 2000-04-27
Heather Jones pose la question :
What do the graphs of cube roots look like?
Walter Whiteley lui répond.
Searching for socks 2000-04-26
Luther Jackson pose la question :
There are 10 red socks and 10 blue socks in a drawer. Aside from their color the are identical. All of the socks in the drawer are mixed up. If the room was pitch black, How many socks would you need to pull out of the drawer to be certain that you have a pair that matches? Why?
Penny Nom lui répond.
Paying with silver 2000-04-26
Luther Jackson pose la question :
A silver prospector is unable to pay his March rent in advance. He owned a bar of pure silver, 31 inches long, so he made the following arrangement with his landlady. He would cut the bar, he said into smaller pieces. On the first day of March he would give her and inch of the bar, and on each succeeding day he would add another inch to her amount of silver. She would keep this silver as security. At the end of the month, when the prospector expected to be able to pay his rent in full, she would return the pieces to him.
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Claude Tardif and Penny Nom lui répond.
The weight of a watermelon 2000-04-25
Lori Speir pose la question :
If I have a 100 pound watermelon and it is 99% water. If it sits out in the sun all day and is now only 98% water what does it weigh now?
Penny Nom lui répond.
An expected value 2000-04-24
Carl Pride pose la question :
Suppose that in a statistics class of size 23, each student has a probability of passing of 73 percent.

sample:

What is the expected number of students who will pass??


Harley Weston lui répond.
Conversions 2000-04-23
Tara pose la question :
750 lbs = ___ tons

How do I figure this out!? I know that 1 ton is 2000 lbs, how do I figure out this answer?
Penny Nom lui répond.

Adding fractions 2000-04-23
A grade 6 student pose la question :
In adding fractions, how do I rewrite the fractions so that the denominators are equal? The problem is 3/4 + 1/6 =
The other problem is 11/18 + 4/9 =

Penny Nom lui répond.
A colony of bacteria 2000-04-22
Nicci Demmin pose la question :
Suppose that the bacteria in a colony can grow unchecked, by the law of exponential change. The colony starts with one bacterium and doubles every half hour. How many bacteria will the colony contain at the end of 50 hours?
Penny Nom lui répond.
Side length of an octagon 2000-04-22
Unknown pose la question :
If I have an octagon that is 12 feet across (side to opposite side) how can I find the length of the sides?
Harley Weston lui répond.
Two gross minus two score 2000-04-20
Georgie pose la question :
What is two gross minus two score?
Chris Fisher lui répond.
Circumference = Area 2000-04-19
Scot George pose la question :
The area and circumference of a circle has the same measurement. Find the radius.
Chris Fisher lui répond.
Chisanbop 2000-04-19
Steven D. Edmonds pose la question :
I once heard about a manual counting method which when learned at an early age allowed one to be able to perform large calculations manually. I believe that name of the method (phonetically) was "chisenbok".
Harley Weston lui répond.
Question regarding Combinations and permutations 2000-04-19
Paul Stoner pose la question :
I am a programmer and I have a quick question. I have 5 criteria which will either be true or false. If a criterion is true it returns its ordinal representation, if false it returns 0. I then combine these results to determine where to go in my program. My question is: How can I figure out the number of combinations I will need?
Patrick Maidorn lui répond.
Math in various careers 2000-04-18
Jennifer Jones pose la question :
I am a Fifth grade student researching how math is used in various careers. What kind of math is used in your career? How do you use math?
Harley Weston lui répond.
Borrowing 2000-04-17
A college student pose la question :
How would you explain borrowing to an elementary school student?
Penny Nom lui répond.
Factoring trinomials that are squared 2000-04-17
A student pose la question :
I have a question that I really need an answer to. I need help with factoring trinomials that are squared.
Penny Nom lui répond.
Uniting algebra and geometry 2000-04-16
Beth pose la question :
Who is the mathmatician that united algebra and geometry???
Claude Tardif lui répond.
Finding a Quadratic Equation given the roots 2000-04-16
A secondary student pose la question :
How do I find the equation for the quadratic with roots at 2-i and its complex conjugate?
Harley Weston lui répond.
Sample variance 2000-04-16
Jonathan Freeman pose la question :
I was just reading your article entitled "A Note on Standard Deviation" I'm now teaching a unit on s.d. and my students were wondering why one uses a denominator of n for a population and n-1 for a sample. I saw in your article that this is because "[the quantity] tends to underestimate sigma... and other technical reasons." To which my students again asked... "Why?" Could you please elaborate a bit on the "other technical reasons" perhaps in terms a high school senior (or their teacher...) could understand?
Harley Weston lui répond.
All the roots of x^6 - 64 2000-04-15
Dakota pose la question :
Find ALL zeros of P(x) = x 6 - 64
Walter Whiteley lui répond.
The area of a triangle using calculus 2000-04-15
Todd Bowie pose la question :
Hi, I am not a student but am reviewing calculus for an upcoming interview. I would like to know how to derive the area of a triangle using calculus. Thanks!
Patrick Maidorn lui répond.
Rounding 2000-04-15
Tawana Brown pose la question :
I was uncertain as to whether a number such as 85.25 rounding to the nearest tenth would be 85.3 or 85.2. I thought I had heard somewhere that if 5 is the last number that you don't round up. But I have also heard that anything 5 and above you do round up. It's been awhile since I've done rounding, so I need a refresher course.
Walter Whiteley and Harley Weston lui répond.
Job outlook 2000-04-12
Shelby Faust pose la question :
what is the future demand, in numbers, of a secondary mathematics teacher? what are the projected costs for this career? what technology skills will be needed for this career?
Walter Whiteley lui répond.
Logs 2000-04-12
Jessica pose la question :
Write as a single log 3ln x - 2ln(y+e) + 5ln(x-12) - 4ln y
Harley Weston lui répond.
Infinite sets 2000-04-12
Brian Provost pose la question :
Here's the deal: There are an infinite amount of integers (1,2,3...). Agreed? There are an infinite amount of even integers, too (2,4,6...). Agreed? By convention, infinity equals infinity. Yet common sense tells us there are obviously more integers than there are even integers. Prove this to be true mathematically.
Harley Weston lui répond.
Natural numbers 2000-04-12
Sara pose la question :
What is a natural number???
Penny Nom lui répond.
Estimates 2000-04-11
Sue Jordan pose la question :
I am looking for examples of estimates for underestimating and overestimating. When would you do each one. For my child age 11 6th grade.
Penny Nom lui répond.
Geometric sequences 2000-04-11
Jodie pose la question :
I am in a grade ten principles class and was taught how to do geometric sequences and series but no one in my class understood what we were taught. Our teacher is one of few to use the new curriculum which used to be the grade twelve curriculum. Could you please explain to me how to do geometric sequences and how to find the different terms and sums. Thank you very much!
Harley Weston lui répond.
Magic triangles 2000-04-11
Sandy pose la question :
My tutoring student brought math homework today in the form of a "magic triangle". There are three spaces along each side for missing numbers. The sums of the numbers along each of the 3 sides should be the same. Use the numbers 4 through 9. Don't use any number more than once. The sum of the numbers on each side should be 20. What is the logic behind solving a problem of this kind?
Claude Tardif and Harley Weston lui répond.
White and blue paint 2000-04-09
Lauren Emerson pose la question :
A truck full of cans of blue and white paint flips over on the road. There are dots of blue and white paint everywhere. Prove that two dots of the same color paint are exactly pi feet apart.
Penny Nom lui répond.
How many zeros? 2000-04-09
Greg Potts pose la question :
The natural numbers 1 to 25 are multiplied together (1 x 2 x 3x..24 x 25). How many zeros are there in the product of this multiplication?
a)6 b)7 c)5 d)10 or e)4?

Harley Weston lui répond.
2^32 + 1 2000-04-08
Un Etudiant pose la question :
232 +1 can be divided by 641 , why?
Claude Tradif lui répond.
Star-multiplication 2000-04-07
Greg Potts pose la question :
I have this question to answer and I don't know where to start. 1*9=0, 9*8=72 and 2*8=9, then 9*9 =?
Penny Nom lui répond.
42% of 70 2000-04-07
Nikkie pose la question :
What is 42% of 70?
Penny Nom lui répond.
Surface area of a cylinder 2000-04-07
Jim Campbell pose la question :
I am going to cover the outside of a shaft with some material. How do I figure the square inches of the outside surface of the shaft? Shaft is 6" in diameter and 24" long
Harley Weston lui répond.
History of a meter 2000-04-07
Jarod Fischer pose la question :
The length of a meter has been determined in three different ways. The first and original way was determined in 1798. The second way was determined in 1960. The third and current way was determined in 1983. What were the three ways and why were the first two abandoned?
Harley Weston lui répond.
Lining a cone 2000-04-06
Jim Campbell pose la question :
I am not a student, I am trying to solve a business problem. The question. If I want to put a lining in a chute that is cone shaped, how do I calculate the size steel plate I need to do that. The cone is 10' in diameter at the top and has a 20" hole at the bottom. The total height of the chute is 8'.
Harley Weston lui répond.
Why are equivalent fractions equal? 2000-04-05
An elementary student pose la question :
What is the mathematical reason equivalent fractions are equal?
Penny Nom lui répond.
y = x^x^x^x... 2000-04-05
Michael Hackman pose la question :
Find the derivative of: y = x^x^x^x... on to infinity.
Claude Tardif lui répond.
How many grams are in 1 ounce? 2000-04-04
Kathy G pose la question :
How many grams are in 1 ounce?
Penny Nom lui répond.
Manipulatives 2000-04-04
Jodi Stuker pose la question :
I am a student looking for a good lesson plan using manipulatives to teach multiplication to LD students. They are currently functioning on approximately 3rd grade level in math but are age 12-14.
Penny Nom lui répond.
Nim 2000-04-04
Sandy Daniel pose la question :
Could you please give me any information on this Math Fair topic?
Claude Tardif lui répond.
The square root of 3 2000-04-04
Mr. William pose la question :
Prove that root 3 is irrational
Harley Weston lui répond.
The side length ratios of some triangles 2000-04-04
Alexis Lockwood pose la question :
I am doing a project for my Math 30B class regarding the side length ratios of 45-45-90 degree and 30-60-90 degree triangles. I would really appreciate any assistance in answering the following questions, or even direction to an appropriate web site or resource on the matter.
Harley Weston lui répond.
Interest compounded daily 2000-04-03
Debbie Bracken pose la question :
How do I figure interest that is compounded daily? 8% compounded daily.
Penny nom lui répond.
Why a Right angle? 2000-04-03
Joseph Mizerek pose la question :
I was wondering why a 90 degree angle is called a Right angle. I mean why isn't called a left angle.
Haragauri Gupta lui répond.
Wholesale price 2000-04-02
Lynda Bintz pose la question :
If a product is priced at $4.99 and is marked up 40% how do I calculate the wholesale price?
Penny Nom lui répond.
Running Through a Train Tunnel 2000-04-01
Eugene Chan pose la question :
A man is running through a train tunnel. When he is 2/3 of the way through, he hears a train that is approaching the tunnel from behind him at a speed of 60 mph. Whether he runs ahead or back, he will reach an end of the tunnel at the same time the train reaches that end. At what rate, in miles per hour, is he running? (Assume he runs at a constant rate.)

I think the answer (12 mph) is wrong. Also, I believe it should read 1/3 of the way through, but don't know how to prove it. Could you come up with some way to prove it, please? I would really appreciate it.


Penny Nom lui répond.
Filling a hole 2000-04-01
John McNeill pose la question :
I have an area 20 feet long and 12 feet wide It starts out at a depth of 4 inches and ends up at 0 inches. How much sand do I need to fill the excavation.
Penny Nom lui répond.
Symmetric Primes 2000-04-01
Marlene Moore pose la question :
Hi...Im in 9th grade and am having a hard time figuring out symmetric primes. Heres the problem:

Find two pairs of symmetric primes of 20. Symmetric primes of 15?


Claude Tardif lui répond.
Careers after a math degree 2000-03-31
Jeanne Hyer pose la question :
What type of careers can a person have with a math degree, and what is the closest thing that you have to an undergraduate degree in financial mathematics? (Administration, math, actuarial science, etc.)
Harley Weston lui répond.
Word problems 2000-03-31
Amy pose la question :
Question:
  1. a north bound train left at noon. four hours later a south bound train left the same station. at 5 o'clook they were 160 miles apart. what was the rate of both if the north bound train was going 20 miles faster than the other one.
  2. clark's final exam was given 5 times the weight of the weight of a weekly test. the avgerage of 15 weekly test was 91. the overall weighted average was 85. what did he make on the final.

Penny Nom lui répond.
Hats, jackets and gloves 2000-03-30
Max pose la question :
Find the one that does not belong 66 333 99 111 88

also if you have 3 hats and 3 jackets and 3 gloves, how many different combinations of a hat and a jacket and gloves can you wear?
Claude Tardif and Penny Nom lui répond.

Riemann sums 2000-03-30
Joshua D. Parham pose la question :
If n is a positive integer, then
 
     lim   (1/n)[1/(1+1/n) + 1/(1+(2/n) + ... + 1/(1+n/n)] 
n->infinity 

can be expressed as the integral from 1 to 2 of 1/x dx
Penny Nom lui répond.

Making fruit salad 2000-03-29
A grade 5 student pose la question :
Miss.Muffet males a fruit salad by adding 31/2 pounds of grapes and 4 1/4 pounds of apples to every 2 1/4 pounds of melon. How many pounds of grapes does she use in 50 pounds of fruit salad?
Claude Tardif lui répond.
The world of percentage. Price tags everywhere 2000-03-27
Lydia pose la question :
I know there is a formula to be utilized for finding the percentage of a number, like most math. You just simply need to remember the formula for finding the number. Please put me on the path.

How does one figure out 10% or 15% of a total number asked? Say... 120

Reverse: 15 is what percent of 120, I know the answer should be the same but how is the formula applied?


Harley Weston lui répond.
Taxis in Chicago 2000-03-27
A high school student high school student pose la question :
Suppose that taxis pick up and deliver passengers in Chicago, which is divided into three zones. Records kept by the drivers show that of the passengers picked up in Zone 1, 50% are taken to a destination in Zone 1, 40% to Zone 2, and 10% to Zone 3. OF the passengers picked up in Zone 2, 40% go to Zone 1, 30% to Zone 2, and 30% to Zone 3. Of the passengers picked up in Zone 3, 20% go to Zone 1, 60% to Zone 2 and 20% to Zone 3. Suppose that at the beginning of the day, 600 of the taxis are in Zone 1, 100 in Zone 2, and 300 in Zone 3. What is the distribution of taxis in the various zones after all have had two riders?
Harley Weston lui répond.
Division 2000-03-26
Kelly Allen pose la question :
My 8 year old daughter had 12 bracelets which she arranged into 4 piles of 3. Did she divide 12 by 3 or by 4?

Most people I've asked can only offer an opinion. What I'm looking for is a definitive answer, if there is one.

My husband says the number of sets is the answer: 12 divided by 3 = 4 Most others I've asked said that the amount in each set is the answer: 12 divided by 4 = 3


Harley Weston lui répond.
Divisibility by 3 2000-03-24
Pat Walsh pose la question :
W hy does it work when you add the digits of a number then divid by three to see if the number is divisible by three
Penny Nom lui répond.
Increasing the weight 2000-03-23
Lee Millard pose la question :
A weight of dimension a, b is to have its weight increased by w% by bolting plates of the same material along the top and one side (but not at both ends). The top plate and side plate have the thickness, x. Find the thickness of the plates for a given weight increase of w%.
Penny Nom lui répond.
Sylvester's Problem 2000-03-23
Sheryl Webb pose la question :
I am trying to find a proof of the theorem: Given n points in a plane, there is a line that contains exactly two points.
Chris Fisher lui répond.
A parabola problem 2000-03-23
Morin pose la question :
I need to prove that if parabola x2=4py has a chord (not necessarily a focal chord) intersecting it at points A and B, with tangents to the parabola at points A and B that intersect at C, then a line drawn through C and the midpoint of the chord M is parallel to the y-axis. Further, prove that the point D where this line intersects the parabola is the midpoint of line CM.
Penny Nom lui répond.
Reflex angles 2000-03-22
D. Reed pose la question :
What is the name of an angle that exceeds 180 degrees?
Penny Nom lui répond.
Rule of 78 2000-03-22
Dan Baumgarten pose la question :
Can you explain the rule of 78 and the reverse rule of 78? Thanks.
Claude Tardif lui répond.
Surface area of a sphere 2000-03-22
Gina Wilkie pose la question :
How can I demonstrate to my middle school students the reason for the formula for the surface area of a sphere?
Walter Whiteley and Chris Fisher lui répond.
I am in lowest terms. 2000-03-21
Travis Fox pose la question :
I am in lowest terms. When you double my numerator and my denominator the result is 10/15.
Penny Nom lui répond.
Compounding continuously 2000-03-21
Gina pose la question :
You deposit $1500 in an account that pays 6.5% annual interest, compounded continuously. Find the balance after 10 years.

I'm not sure what to do with the "compounded continuously" part.


Penny Nom lui répond.
Binomial coefficients 2000-03-21
Howard Lutz pose la question :
How do you find each successive numerical term in this equation y+dy=(x+dx)5 =x5+5*x4dx+10*x3(dx)2+10*x^2(dx)3+5*x(dx)4+(dx)5 I would appreciate an explanation of the method to find the numeric coefficient in a binomial expansion
Penny Nom lui répond.
A system of equations in five unknowns 2000-03-20
Will pose la question :
I have been having some problem with the following question for some time. I would appreciate any help on solving the problem or a solution.

Q: Assume that a system of equations in the unknowns x1, x2, x3, x4 and x5 when converted to row echelon form gives

.
.
.

Penny Nom lui répond.
root(-1)* root(-1) 2000-03-20
Michael Moran pose la question :
i squared = -1

but

i squared = root(-1)* root(-1)
= root( -1*-1)
= root(1)
= 1
-1 doesn't = 1

can you help me with my question


Claude Tardif lui répond.
Travelling from A to B 2000-03-20
Matt pose la question :
A car is traveling from point A to point B. Point A and point B are 30 miles apart. A car travels 30 miles an hour from point A to point B and then goes back to point A. How fast does the car have to go back to average 60 miles an hour?
Claude Tardif lui répond.
Six digit numbers using 1,2,5,6,7, and 9 2000-03-20
Rachel pose la question :
How many different six-digit numbers can you make using the digits 1,2,5,6,7, and 9? How many of these six digit numbers are divisible by six?
Claude Tardif and Denis Hanson lui répond.
A quantitative methods course 2000-03-19
Mark Haberman pose la question :
Question:
Last semester, the grade distribution in a quantitative methods course had the following distribution: 10% A, 25% B, 35% C, 10% D, and 15% W (withdrew).
  1. If this grade distribution does not change this semester, what is the probability that a randomly selected student will make at least a D?
  2. If this grade distribution does not change this semester, what is the probability that a randomly selected student will fail the course?
  3. If this grade distribution does not change this semester, what is the probability that a randomly selected student who finished that course (did not withdraw) made a grade of D or better?

Harley Weston lui répond.
The Terror Run 2000-03-18
Danny Mclean pose la question :
A fairground's most popular attraction is a roller coaster ride known as the Terror Run. One stretch of track is called the Missile Path and is in the form of a parabolic curve. B is 180m horizontally from A and the highest point of the curve is 100m above A and B.

A.. The owner works out a quadratic expression to describe the Missile Path. What is the expression He found?

B.. A safety Engineer examined the structure and observed that points A and B were likely to be damaged due to the steepness of the Missile path near these points. The owner can see no way to make the Missile path less steep near A and B and to keep the height of the ride the same. HOW CAN IT BE DONE?


Harley Weston lui répond.
Four questions 2000-03-17
Ibrahim Bin kasmin pose la question :
  1. What is a hexahedron?(please show a picture of a hexahedron).
  2. How do we make a cube out of three pyramids?(show me the picture).
  3. How do we find the approximate perimeter and area of a hibiscus leaf?
  4. What is a Pascal triangle?

Penny Nom lui répond.
The Kennedy Pep Club 2000-03-17
David Grimmer pose la question :
The Kennedy Pep Club rented a bus to take all of its members to a baseball game. The cost per person was to be $18.00. However, those making the trip had to pay $24.00 each because 10 members cancelled at the last minute. How many pep club members took the bus to the game?
Penny Nom lui répond.
Completing a sequence 2000-03-17
David Grimmer pose la question :
Complete the following sequence so that, after the first two terms, each successive term is the average of all the preceding terms.

20__ __ 28 __ __


Penny Nom lui répond.
1000 percent 2000-03-17
Matt Stevenson pose la question :
If one invests $4000.00 and makes 1000% on the investment would he/she have $40,000.00?
Could one figure this by: $4000.00 * 10.0 = $40,000.00?
So is 10 times a number the same as 1000%?

Would 100 times a number be the same as 10,000%?


Penny Nom lui répond.
Division 2000-03-16
Charday pose la question :
What is the easiest way to calculate the least number that can be divided evenly by all the numbers from 1 to 10.
Penny Nom lui répond.
Induction 2000-03-16
William Tsang pose la question :
I am trying to prove a induction question

Sigam r=1 n (2r -1)cube = n square (2 n square - 1)


Harley Weston lui répond.
Functions that satisfy f' = f 2000-03-16
Kevin Palmer pose la question :
Recently my calculus teacher asked his students to try and find any functions whose derivatives where the exact same as the original function.

The only function then I have determined that statement to be accurate in is all the natural exponential functions. Ex. f(x) = ex, f'(x) = ex

If possible could you please email me all the functions that you can find in which the original function and its derivative is identical.


Claude Tardif lui répond.
Putting in a pool 2000-03-16
Katie pose la question :
If your digging a hole for a pool and the pool is:

Length= 11m
Width= 6m
Sallow Depth= 1.1m graduating to
'Deep' Depth= 1.8m

What is the volume of soil that will be taken out? And if a bobcat can excavate and remove 10m3 (qubed) of soil an hour how long will it take him to excavate the soil.


Penny Nom lui répond.
Geometrical solids 2000-03-15
Sarah pose la question :
  1. What geometrical solid has 8 edges and 5 vertices?
  2. What geometrical solid has 12 edges that are all the same length?

Walter Whiteley lui répond.
Rationals, irrationals and integers 2000-03-14
Erin McKeon pose la question :
Why does the letter J represent the set of integers, the letter Q represent a set of rational numbers and the letter P represent a set of irrational numbers? What do each of these letters stand for?
Harley Weston lui répond.
Eligibility in a contest 2000-03-14
Ken Rabley pose la question :
Hi, hoping you can help. Dispute among co-workers. Tell me, what is the correct answer to the following question:
-1936 + (2406/4812) x (4756 - 3256) + 1250

Seems this is the question for eligibility in a contest...We have come up with various solutions, all which may be correct.


Penny Nom lui répond.
Characteristic of a logarithm 2000-03-14
Andrew Strauss pose la question :
What is the characteristic of log base 18 of 1980 ?
Harley Weston lui répond.
Two problems 2000-03-14
Teresa Bostic pose la question :
  1. A man's age at death was 1/29 of the year of his birth. How old was he in 1949?
  2. At a contest, 2 persons were asked their ages. Then to test their ability mathematically, they were asked to give the ages together. One gave 44 and the other gave 1280. The first had subtracted one age from another, and the second had multiplied the two together. What were their ages?

Penny Nom lui répond.
An integer max-min problem 2000-03-13
Paul Servic pose la question :
Maximize Q = xy 2 where x and y are positive integers such that x + y 2 = 4
Penny Nom lui répond.
A trogonometry problem 2000-03-12
A student pose la question :
Find all values of X in the interval 0 degrees <= x < 360 degrees that satisfy the equation 2sin x - cos 2x = 0.
Harley Weston lui répond.
Maximize 2000-03-12
Tara Doucet pose la question :
My question is Maximize Q=xy^2 (y is to the exponent 2) where x and y are positive integers such that x + y^2 ( y is to the exponent 2)=4
Harley Weston lui répond.
An equilateral triangle in a circle 2000-03-11
Michael Setlik pose la question :
An equilateral triangle is drawn within a circle such that all three points of the triangle just touch the inside of the circle. Given the diameter of the cicle as six inches what is the length of the sides of the triangle?
Harley Weston lui répond.
Simultaneous equations 2000-03-11
Laura Molck pose la question :
My name is Laura Molck and I am in Year 11 in Australia. Please help me with the following. I know that they are all simultaneous equations which I can do but I have trouble with the formulae to work the equations. Can you please help!!

1. A tent manufacturer produces 2 models, Outback and Bushwalker. From earlier sales records it is known that 20% more of the Outback model is sold than the Bushwalker. A profit of $200 is made on each Outback sold, but $350 is made on each Bushwalker. If during the next year a profit of $177,000 is planned how many of each model must be sold?


Penny Nom lui répond.
Completing the square 2000-03-11
Sandra pose la question :
How do i complete the square and leave in simple radical form? x squared + 18x - 17=0
Penny Nom lui répond.
Congruent parts of congruent figures 2000-03-10
Erica pose la question :
Yesterday, I recieved a test problem asking to prove two line segments equal. Here is the problem as I was given it:

Given: paralleogram ABCD
AE is perpendicular to DB
CF is perpendicular to DB
Prove: AE is equal to CF

I answered the problem as follows:
.
.
.
Walter Whiteley lui répond.

A goat problem 2000-03-10
Nancy pose la question :
A farmer has a fenced-in, circular field with an area of about one acre. A goat in the field is tethered to one of the fence posts with a rope which gives the goat approximately one-half acre of grazing area. To the nearest foot, how long is the rope?
Chris Fisher lui répond.
Systems of linear equations 2000-03-10
Ann Marie Devereux pose la question :
hi there!!, I guess I have a problem!!!
  • 3x+4y=10 (over)
    4x+y=9

  • 2x=5y+3 (over)
    x=3y+1


Penny Nom lui répond.
Grazing area for a goat 2000-03-10
Amy pose la question :
A goat is tied in the middle of a side of a square building whose sides are 2 yards long. The rope is 4 yards long. What is the grazing area for the goat?
Harley Weston lui répond.
Box and whisker plots 2000-03-09
Brett Blake pose la question :
Do you have any information on Box and whisker graphs?
Harley Weston lui répond.
Some equations 2000-03-08
Maria pose la question :
Hi, could you help me with these questions:

Find x & solve

  • 7-2x/3=9
  • 4x+3/5=-2
  • 6-2x=14
  • -1/7x=-4/3+1/6

Penny Nom lui répond.
Mathematical deduction and mathematical induction 2000-03-07
Espera Pax pose la question :
What are mathematical deduction and mathematical induction, and what is the difference between them?
Harley Weston lui répond.
Making dolls 2000-03-07
A 6th grader pose la question :
How many small dolls can be made from 3 lbs. of dough if each doll uses 7/8 lbs
same question if each doll takes 3/8 lbs.

Penny Nom lui répond.
A mixture problem 2000-03-06
Rebecca Edwards pose la question :
A tank in which cholocate milk is being mixed contains a mixture of 460 liters of milk and 40 liters of chocolate syrup initially. Syrup and milk are then added to the tank at the rate of 2 liters per minute of syrup and 8 liters of milk per minute. Simultaneously the mixture is withdrawn at the rate of 10 liters per minute. Find the function giving the amount of syrup in the tank at time t.
Harley Weston lui répond.
Is a sheet of paper 2-dimensional? 2000-03-06
Jaclyn Evans pose la question :
One day, we were discussing 3-dimensional items. Is a sheet of paper considered a 3-dimensional shape? Or is it 2-dimensional as described by 8.5 by 11 size? Also, could you give me an example of a 4-dimensional item or scenario?
Harley Weston lui répond.
10 000 000 = a x b 2000-03-06
Spencer Jaffe pose la question :
What two numbers that don't end in zero, multiplied equal 10,000,000.
Claude tardif lui répond.
Two calculus problems 2000-03-03
Tara Doucet pose la question :
  1. The height of a cylinder with a radius of 4 cm is increasing at rate of 2 cm per minute. Find the rate of change of the volume of the cylinder with respect to time when the height is 10 cm.

  2. A 24 cm piece of string is cut in two pieces. One piece is used to form a circle and the other to form a square. How should the string be cut so the sum of the areas is a maximum?


Harley Weston lui répond.
Angle of Intersection of Two Lines 2000-03-02
Veronica Patterson pose la question :
I am having a real hard time trying to figure out this problem. Could you please help me! The homework question says to find the acute angle of intersection between the two lines y=3x+1 and y=(1/2)x-1. (It also says to use the results of a problem I had already figured out.) That problem was to use information from a picture shown that tan(theta sub1-theta sub2)= ((m sub2- m sub1)/(1+(m sub1 * m sub2))). I used the difference identity of tangent to figure out the answer. Any help on this problem would be greatly appreciated.
Harley Weston lui répond.
Triangular numbers and square numbers 2000-03-02
Emily McCallum pose la question :
Would someone find me some math activities using triangular numbers and square number. Especially acitivities that actually form the shapes. They need to be at the 5th grade or 6th grade level. But you can not find anything that can be tauht at these level, that fine. I just need to be able to teach this new subject or kind of math to my kids.
Rick Seaman and Penny Nom lui répond.
The positive effects of mathematics on human's thought 2000-03-02
Yucel Tucker pose la question :
I am a student of secondary school. I have to prepare a homework about " the positive effects of mathematics on human's thought". If you help me I'll be pleased. thank you...
Walter Whiteley lui répond.
Pythagorean triples 2000-03-01
Bob Ross pose la question :
Could you please tell me what pythagoria triad is.I am a year 10 student.
Chris Fisher lui répond.
Proportionality in a triangle 2000-03-01
Courtney Smith pose la question :
I would appreciate assistance with the following problem In triangle ABC,segment MN divides sides(segment)AC and (segment)AB proportionally. If the coordinates are A(3,7),M(0,10) and N(8,22) and if AM:MC = 3:1, find the coordinates of B and C.
Penny Nom lui répond.
Saving for college 2000-03-01
Andrew Kunz pose la question :
SAVING FOR COLLEGE In this project, you will forecast a friend's finances. Jane has received $75 from her grandparents on every birthday since she was one year old. She has been saving the money in an account that pays 5% interest. She is saving her money to help you pay for her college education, which she will start this fall after her 18th birthday. She also has been receiving birthday checks from her other relatives, but these didn't start until she was 12 years old. The amounts of these checks from her 12th birthday until her 18th birthday are $45, $45, $55, $50, $55, $60, $65.

How much money will she have saved just from her birthdays by the time she starts college? IS this a reasonable amount to pay for a used car during her junior year in college? If she had invested her money in a different accoutn that had earned 7% interest, how much more money would she have saved?


Penny Nom lui répond.
Folding a page 2000-03-01
Krista Bischoff pose la question :
One corner of a page of width a is folded over and just reaches the opposite side. Express L, the length of the crease, in terms of x and a.

I can't get the picture to copy to this form so I guess I will have to try and describe the picture the best that I can. The top right hand corner is folded to the left side, almost half way down. The width of the paper is a ( the width of the bottom part which is not folded.) The creased side is L and the part shorter part of the folded area is x (the part that would have been the top right of the original piece.)


Chris Fisher lui répond.
What's the next term? 2000-02-29
Meredith O'Neill pose la question :
At this point, the whole family wants to know the answer. if possible an explanation. thanks
a sequence ?

16,37,58,89,145 ??


Chris Fisher lui répond.
Area of a circle 2000-02-29
Michelle Buboltz pose la question :
My name is michelle and I just need to convert 25 ft across a circle into how many square feet.
Penny Nom lui répond.
A negative times a negative 2000-02-29
Michael J. Butler pose la question :
I have reviewed the answer in relation to the question of why (-3)x(-2)=6; however, I am still not able to properly explain the reasoning to my son, Jonathan, who is in grade 7. I want him to understand the reason for the rule that the multiplication or division of two negative numbers equals a positive number. Can you help?
Chris Fisher lui répond.
Order of operations 2000-02-27
Mildred Saulsbery pose la question :
Find the value of the expression.
 6(5+1) - 9(1+1) _____________    5(8 - 6) -23 

Harley Weston lui répond.
Fractions in algebra 2000-02-27
Leslie pose la question :
Question:
add (4x+1)/(x-8) + (3x+2)/(x+4) + (49x+4)/(x^2-4x-32) and

solve x - 6/(x-3) = 2x(x-3)

Penny Nom lui répond.
Factoring, primes, GCF and LCM 2000-02-27
Ruth Kroek pose la question :
My son is in grade seven, he has to do a Factoring Booklet the areas covered are:
  • Prime #'s
  • Composite #'s
  • Rainbow Factoring
  • Finding Multiples (consecutive multiples)
  • Finding GCF of 2-3 numbers uning Rainbow factoring
  • Finding LCM of 2 numbers using consecutive multiples
  • prime factor trees
  • prime factor ladders
  • finding GCF of 2 numbers using Prime number Method
Although his text 'Math Power' gives some information, we are at a loss ..

Penny Nom lui répond.
Building a pyramid 2000-02-26
Francis X. Hines Jr. pose la question :
I am presently trying to build a pyramid. I can understand that the base has 90 degree angles on the first plane which is the outline of the square that makes up the floor.

As close as I can figure the slope of each wall face is 35 degrees or 35.7 to be exact if I am correct by using 360 as the total of the three interior angles.Now , I run into a compound angle where the corners meet what would be the angle created by the two 35 degree angles that would allow for the 90 degree edge to continue.

Because I'm working in three dimensions I also need to be sure that my math would be correct when I substract 35 from 90 to aquire the angle of the narrow edge as to allow for a 90 degree surface to be present ..to allow for another level to be added with only the base line being shortened. I hope you can understand what it is that I'm asking assistance with.I would greatly appericate your help.


Chris Fisher lui répond.
Polar coordinates 2000-02-24
Tran Trung pose la question :
How do I convert r = 2/(2sin(theta) - 3cos(theta)) to rectangular and x2 + y2 -2y = 0 to polar form?
Harley Weston lui répond.
Slant height of a cone 2000-02-24
Jocelyn Wozney pose la question :
I need help with this problem for my high school calculus class. Any help you can give me will be greatly appreciated-I am pretty stumped. "Express the volume of a cone in terms of the slant height 'e' and the semi-vertical angle 'x' and find the value of 'x' for which the volume is a maximum if 'e' is constant.
Harley Weston lui répond.
The isoperimetric theorem 2000-02-24
Raj Bobal pose la question :
How can you prove Mathematically that the maximum area enclosed by a given length is a circle?
Chris Fisher lui répond.
Hexagons 2000-02-23
Mohd. Amjad pose la question :
I want to know about hexagons. What is the area and the perimeter of an hexagon?
Penny Nom lui répond.
More on googols 2000-02-23
Kevin Brennan pose la question :
Could you please give me a couple of examples of when you MATH guys would use a google. Do youu measure, like, galaxies with it ? Or was it created to keep track of Mr Gate's bank account.
Penny Nom lui répond.
Triple angle formula 2000-02-23
Sara pose la question :
Can one derive a triple angle formula for sine and cosine? If so, how?
Chris Fisher lui répond.
A triangle and a circle 2000-02-23
wendy pose la question :
If a triangle of base 6 has the same area as a circle of radius 6, what is the altitude of the triangle? I am having trouble with altitude.
Penny Nom lui répond.
Some integration problems 2000-02-23
Tim Valentine pose la question :
I am having a great deal of difficulty with the following integrals, can you help? I think they need the use of trig substitution or integration by parts but I cannot figure out how to begin. Thanks!

The integral of 1/(2+3x2) dx.

and

The integral of x * square root of (4x+5) dx.


Harley Weston lui répond.
A trig identiry 2000-02-23
Ashlee pose la question :
I am having problems doing this problem. Can you help?

Verify the identity: (1+cot2X)(1-cos2X)=2


Harley Weston lui répond.
Party favors 2000-02-22
Krystina Fernandez pose la question :
Luanne was making party favors for her little sister's birthday party. Each party favor was in the shape of a cube. Luanne had pink and purple paint to paint the cubes and she could paint each face only solid pink or solid purple (no dots,stripes,ect.).For example, one cube may be all purple, another may have two purple faces and four pink faces. Her little sister wanted to have a different cube for each guest.(A cube is not considered different if it can be turned so that all it's sides match the corresponding sides of another cube.)How many different cubes was it possible for Luanne to make?
Claude Tardif lui répond.
A moving point on the graph of y=sinx 2000-02-22
Veronica Patterson pose la question :
Find the rate of change of the distance between the origin and a moving point on the graph of y=sinx if dx/dt=2 centimeters per second.
Harley Weston lui répond.
Pi 2000-02-22
Shelley Collier pose la question :
Numbers that can be written in the form p/q where p and q are integers, (q not 0), are known as rational numbers. What you are missing is that p and q must be integers. The fact that Pi is irrational means that you can't have a circle with both the circumference and diameter being integers. In fact you can't even have the circumference and diameter both rational since the quotient of two rationals is again a rational.
Claude Tardif and Penny Nom lui répond.
A valentines project 2000-02-21
Courtney Dohoney pose la question :
I was assigned a valentines project. Our job is to make a valentines card that has a math theme. On my valentines card I would like to include the set of equations that when graphed look like a heart. If you can figure out a set of equations and get it back to me I would be very happy.
Harley Weston lui répond.
The quotient rule 2000-02-21
Charlene Anderson pose la question :
Question: I came across a question in our book that states: Let Q(x) = N(x) / D(x) Then re-write Q(x) in a form that can utilize the Power and Product Rules. Use this rearranged form to derive the Quotient Rule.

The Quotient Rule can be derived from the Power Rule and the Product Rule.

One must also use the chain rule too, right?


Harley Weston lui répond.
Mass of the earth 2000-02-21
Terry Broughton pose la question :
My name is terry i am 15 my question is how much does our planet earth weigh ?
Chris Fisher and Harley Weston lui répond.
Why counterclockwise? 2000-02-21
Drew pose la question :
Why do the numbers of quadrants in a graph increase in a counter clockwise pattern? Why aren't they numbered increasingly in a clockwise pattern?
Chris Fisher lui répond.
Irrational algebraic functions 2000-02-21
Bucky Cadena pose la question :
Here is the multipart problem:

Given f(x) = x-3* squareroot of x + 4

What does the f(x) intercept equal Find the two values for which f(x) = -5 Find the one value for which f(x) = -3


Harley Weston lui répond.
Three factors 2000-02-21
A parent pose la question :
Question from a parent helping a child, grade 4, with homework. Can a number have three factors? Name three numbers that have three factors.
Penny Nom lui répond.
Perimeter of an ellipse 2000-02-21
Kurtis Proffit pose la question :
What is the formula for the perimeter or circumference of an ellipse?
Chris Fisher lui répond.
Number sense 2000-02-17
A college student pose la question :
I am a college student and I am to answer the following question: Describe ways of telling by simple inspection when a fraction has a value close to 0; close to 1/2; and close to 1. I am to imagine that I am a 3rd grader answering this question. Any thoughts please?
Penny Nom lui répond.
Jogging up a hill 2000-02-17
Aaron Williams pose la question :
A man jogs down the hill at 6 miles per hour and back up at 4 miles per hour. The total time that he travels is 5/4 hours. What is the total distance that he jogged.

The solution is supposedely 3 miles, but i believe that it is 6. Can you help me? Please.


Claude Tardif lui répond.
A trig identity 2000-02-17
Eric pose la question :

Question:
How do I solve this problem?

 sin3x   cos3x _____ - _____ = 2 sinx cosx 

Chris Fisher lui répond.
The length of a cylinder 2000-02-17
Kelly Wichmann pose la question :
What is the formula to figure the volume of a cylinder? We have a cylinder that is 2 3/4" in inside diameter and a gallon of oil that needs to fill it. We are trying to figure out how long the cylinder should be. Can you help us?
Chris Fisher lui répond.
Cross multiplication 2000-02-16
J E Swinton pose la question :
Why does cross multiplication work?

How come canceling work?


Penny Nom lui répond.
Least Common Multiple 2000-02-16
Kathy Heath pose la question :
The way I understand it is for 2,3,9 the least common multiple is 18. Am I right? If so, I guess the least common multiple for 3,4,7 is 105. Please let me know if I'm right so I can tell my daughter.
Denis Hanson lui répond.
Change for a dollar 2000-02-16
Rachelle pose la question :
What is the least positive number of coins that is impossible to give out change for a dollar? It is higher than 50 i know and you can us dimes, nickels, pennies, quarters, 50 cent pieaces and silver dollars.
Claude Tardif lui répond.
2 = 1 2000-02-16
Chuck Kennedy pose la question :
Question:
  1. Assume a=b
  2. Multiply both sides by a, a2=ab
  3. Subtract b2, a2-b2=ab-b2
  4. Factor (a-b)(a+b)=b(a-b)
  5. Cancel like factors a+b=b
  6. Substitue b for a b+b=b
  7. Then 2b=b
  8. Therefore 2=1
Question; Were is the mistake?

Claude Tardif lui répond.
Midpoints and endpoints 2000-02-15
Jessica Sipes pose la question :
I need to know how to find and endpoint using the midpoint and the other endpoint.
Penny Nom lui répond.
Weighing bales 2000-02-15
Thinh Than pose la question :
You have 5 bales of hay. and they were weighed but they didn't weigh them individually, they were weighed in pairs. The pairs were 1&2, 1&3, 1&4, 1&5, 2&3, 2&4, 2&5, and so on. The weights of the pairs were 80,82,83,84,85,86,87,88,90, and 91. Can you tell me how much the bales weigh individually.
Claude Tardif lui répond.
Factors 2000-02-15
Guy Rayfield pose la question :
Please can you tell me the factors of 6

I think the answer is 2 and 3 - am I right?


Penny Nom lui répond.
Is a square a rectangle? 2000-02-15
Jaireh pose la question :
This is something that aroused a debate in class: A rectangle was defined as a parallelogram with 4 right angles. A square was defined as a parallelogram with 4 congruent sides and 4 right angles.

I need written and conclusive proof that some rectangles can or cannot be squares. I tried insisting that some of them can.. but without proof nobody will listen.


Walter Whiteley lui répond.
The sum of repeating decimals 2000-02-15
Caitlin Harris pose la question :
Express 0.111... + 0.121212... + 0.123123123... as a repeating decimal and its equivalent fraction. Show work. Also, are there any extensions to this problem? In other words, are there any questions that we could ask that may be related to this problem?
Penny Nom lui répond.
Counting to a trillion 2000-02-06
Art Keck pose la question :
If I counted one dollar every second, would it take 31,000 years to count to a trillion? If not, could you please explain how long it yould take?
Penny Nom lui répond.
Ten stools 2000-02-06
Haim pose la question :
In a cafe with ten stools, three customers want to be seated, so that no two are next to each other. How many ways can this be done? Do not consider it to be a separate seating if two customers switch seats.
Denis Hanson and Walter Whiteley lui répond.
A 4-by-4 magic square 2000-02-06
Maureen Fitzsimons pose la question :
I need to create a 4x4 grid using numbers .1, .2, .3, .4, ....1.1, 1.2, 1.3,1.4,1.5,1.6 the sum of the number diagonally, horizontally and across all equal 3.4
Penny Nom lui répond.
Is zero an even or odd number? 2000-02-06
Christian Hansen pose la question :
On a list I run, someone posted that 02-02-2000 was the first date since 28-08-888 where all the digits were even. Of course, this provoked a discussion of whether zero was odd, or even, or neither. I remember reading that, for symmetry's sake, it is considered by mathematicians to be even. Any thoughts?
Patrick Maidorn lui répond.
Percentages with decimals 2000-02-06
Andrew Connell pose la question :
I need help with these math questions: How does one convert a percent to a fraction when the percent has a decimal (example-86.5%)?
Penny Nom lui répond.
Tennis doubles 2000-02-04
Brittany Allinson pose la question :
Cheri, Beth and Jacinta are daughters of Mr. Sullivan, Mr. Marchand, and Mr. Benoit. Four of these people are playing tennis doubles. Mr. Benoit's daughter and Mr. Sullivan are partners. Cheri's father and Mr. Marchand's daughter are also partners. There aren't any father/daughter combinations. Who is Cheri's father?
Penny Nom lui répond.
Filbert Family Circus 2000-02-04
Sarah pose la question :
As Clyde moves his broom around the circus ring, he thinks that he has finally found a job where he can make a clean sweep of things. Clyde is sweeping the ring where the lions perform in the Filbert Family Circus. The ring is 76 feet across and Clyde is using a broom 3 feet wide. He starts at the outside edge and works his way to the middle, making circles around the ring. After sweeping 3/4 of the ring, Clyde sees the lions coming with their trainer and scurries out of the ring. How many trips around the ring did he make?
Penny Nom lui répond.
A 16th century mathematician 2000-02-04
Danielle Dombrowski pose la question :
My name is Danielle Dombrowski, I am in the 7th grade and my teacher gave us a riddle to figure out which mathemtician we would have to do a report on. The only problem is that I don't know what the answer is. Can you help? The riddle is

"This 16th century mathematician, having predicted the day of his death, took poison to make sure it came true. Who is it?"


Penny Nom lui répond.
Play ball 2000-02-03
Jessie pose la question :
Here's a calc question that is probably a lot easier than I am making it. If you have a legendary "baseball problem" for the related rates section of Calc I, and you are given that the runner is running from 2nd to 3rd base at a given rate, and the umpire is standing at home plate, and you are given the distance between the bases on the field, how do you find the rate of change of the angle between the third base line (from the point of the umpire) and the runner? Here is a sample prob: Runner is moving from 2nd to 3rd base at a rate of 24 feet per second. Distance between the bases is 90 feet. What is the rate of change for the angle (theta, as described previously) when the runner is 30 feet from 3rd base?
Harley Weston lui répond.
A problem with a radius. 2000-02-01
Howard B Davis pose la question :
We start a Line that goes up 1 unit, then it goes to the Right for 5 units long, and then goes down 1 unit which is the end point. If we draw a circle that is tangent to both ends as well as the mid-point of the horizontal line: How do we find the radius of the arc; in Mathematics, with only this information?
Chris Fisher lui répond.
100% on two tests 2000-02-01
Craig and Chelsea Bruzzone pose la question :
A class of 35 students took a math test and a science test. 12 students got 100% on the math test. 9 students got 100% on the science test. There were 19 students who made less than 100% on both tests. How many students made 100% on both tests?
Penny Nom lui répond.
Mark's life 2000-01-30
Jean and Larry Brandemuehl pose la question :
Mark passed 1/6 of his life in childhood, 1/12 in youth, and 1/7 more as a bachelor. Five years after his marriage, there was born a son who died four years before his father, at half his father's (final) age. How old was Mark when he died?
Penny Nom lui répond.
Percent of improvement 2000-01-30
Steve Quigg pose la question :

In a 1998 survey, 21% polled responded favorably to a question. In 1999, 31% responded favorably.

What is the percent of improvement?


Harley Weston lui répond.
Can't make an equation! 2000-01-30
Maggie Clarke pose la question :
An estate is to be distributed among the wife, 3 children and 2 grandchildren. The children will each receive 2x as much as each grandchild, and the wife will receive 4x as much as each child. If the estate amounted to $115,000, how much will each person receive?
Penny Nom lui répond.
Names of the polygons 2000-01-29
Janemath pose la question :
I have been doing research on the names of polygons with 11 to 20 sides. I have found conflicting names for some of them . for example 18 sided-octadecagon and octokaidecagon. 11sided-undecagon and hendecagon. Why is this? Is one more correct than another? Or are they equally acceptable?
Harley Weston lui répond.
Two problems 2000-01-29
D. J. Anthony pose la question :

Hi, I am taking a course "math for elementary teachers" and I have two problems.

  1. How thick is a sheet of paper in your textbook.
  2. A little island has a population of 1,000 people. It doubles every 30 years. What will the population be in 30 years?, in 60 years?, when will it be over one million?

Peny Nom and Claude Tardif lui répond.
Compatible numbers 2000-01-27
Angie pose la question :
Use compatible numbers to estimate each product and quotient.
23*1/2
1/3*11

Penny Nom lui répond.
Factors 2000-01-27
Pam pose la question :
My son [age 9, 4th grade] has a math problem with factors. I need to know how to do the problem that involves the factor 24. I'm not even sure where to start.
Harley Weston lui répond.
Probability, graph theory and VLSI testing 2000-01-27
Valentin Muresan pose la question :
I am postgraduate student of Dublin City University, Ireland, in the field of VLSI Testing. I am currently working on some heuristics and I need a probability formula. I want to get an expert's point of view in my matter. Say there is an initial list of so called tests: T1, T2, T3, ..., Tn Every test element Ti of the above list has a list of compatibility (incompatibility), which includes all the elements (tests) from the initial list, the Ti test is compatible (incompatible) with. For example, say the initial list is: {T1, T2, T3, T4, T5, T6, T7, T8, T9, T10} and the compatibility lists of these elements (tests) are:
.
.
.

Denis Hanson lui répond.
Quadratics 2000-01-27
Lori pose la question :

Hi my name is Lori. I'm a student, in the 11th grade.I have a problem in quadratic functions. I don't know how to get the numbers into the problem and then how to do the problem. here is one problem the rest are sort of similar to it... y=2x squared. If I were to find out how to get the (x,y) answers then I could graph it but as I said I can't find the numbers to go into the problem.

Also in the equation g: x arrow to y = -x + 4..... how would you know weather it is or isn't a quadratic equation????


Penny Nom lui répond.
Counting guppies 2000-01-26
Sarah Albaugh pose la question :
Out of 200 fish, 99% are guppies. How many guppies must be removed to have 98% of the remaining fish to be guppies?
Penny Nom lui répond.
Quadratic 2000-01-26
Karen Johnson pose la question :
What is the reasoning behind the title quadratic equation?
Penny Nom lui répond.
Mixing oil and gas 2000-01-25
Karen pose la question :
My hubby is ready to use his snow blower and is supposed to use 50:1 measurement....50 parts gas to 1 part oil......how does he do this if he has 1 gallon of gas? How much oil do we use...need info asap.....hopefully you are there!
Harley Weston lui répond.
Complex Roots 2000-01-24
Jess Rutherford pose la question :
How do I find the value of k when 5x2 + k = 3x and has complex roots ?
Penny Nom lui répond.
Euclidean Math puzzle 2000-01-24
Margaret Matthews pose la question :

(Check out this web-site: Simeon's Triangle Puzzle )

I have tried to figure out how this could be, because everything I know about it tells me it can't be. However, I can't seem to make it NOT work.

Two right angle triangles. They are each cut up into four identical pieces. In the first, all the pieces fit together so that there are NO empty spaces; in the second, presumed to be identical in size to the first, the pieces are slightly rearranged, and now, there IS a space in the triangle.


Patrick Maidorn and Claude Tardif lui répond.
Word problem 2000-01-24
April pose la question :

Ok, my algerbra teacher gave me this problem and by just looking at it I can tell what the answer is but he wants me to show how I got the answer in an equation form.

The tempature at 7am on a cold day was -4 degrees Celcius. At 3pm the tempature was 1 degree Celcius. Write and solve an equation to find out how many degrees the tempature rose between 7am and and 3pm.


Penny Nom lui répond.
Functions 2000-01-23
Tara pose la question :
Hi my name is Tara, I have two math problems that I need help with in my calculus math class.

  1. If f(x)= x - 2 show that (x+3)f(x)-(x+2)f(x+1)+4=0

  2. Graph this function and use the graph to determine the range y=2x2 - 8x - 3

Harley Weston lui répond.
Frogs and lily pads 2000-01-23
Nick pose la question :
There are 5 lily pads and 4 frogs, 2 Red and 2 Green, how many moves does it take for them to swap sides?
Answer: 8

I have a formula which will tell you how many moves it will take with different total numbers of frogs, it is [(F*F)/4]+F Where F is the number of red frogs add the number of Green frogs. This formula only works with numbers of frogs that are the same on each side. What I would like to know is why this formula works and why you have to divide it by 4?


Penny Nom lui répond.
The limit of f(x)/x 2000-01-22
Laurent Jullien pose la question :
I would appreciate help to prove that a twice continuously differentiable convex function from R+ to R has the property that f(x)/x has a limit when x tends to infinity.
Claude Tardif lui répond.
Domain of a function 2000-01-19
Stacey Hutchison pose la question :

What is the domain of:

f(x) = -1/(x + 4)


Patrick Maidorn lui répond.
Arclength of a circle 2000-01-19
Holly pose la question :
What is the formoula for finding the arc length of a central angle of a circle??
Harley Weston lui répond.
Logarithms 2000-01-18
Jennifer pose la question :

Hi I have a test tomorrow and I was wondering if you could help me with these two problems.

  1. Explain how to express y in terms of x if log3y=4log3(2X)

  2. The LN key on your scientific calculator is not working, but the ex and LOG keys are. Write directions for calculating a natural logarithm using the ex and LOG keys. Explain why these directions will get you the right answer.


Harley Weston lui répond.
Pyramids and prisms 2000-01-18
Tyler pose la question :
What's the definition of a Triangular Prism and a Triangular pyramid.
Penny Nom lui répond.
Algebra 2000-01-18
Candis pose la question :
I want to know what exactly is Algebra?
Not how to do it, or methods. Just what is it?

Allen Herman lui répond.
Ax + By = C 2000-01-18
Fatiha Khanboubi pose la question :
I was wondering if you could please explain to me how I would write the equation of line through the given points [(4,1), (6,3)] in Ax+By=C form.
Harley Weston lui répond.
Solving an equation 2000-01-17
Shelley's Mom pose la question :

My daughter has an assignment in math that includes this equation:

-6b+5= -10

I've tried to help her with a scale. We've figured that you subtract 5 from each equation so its not -6b = -15. Is this correct and can you help us figure out the next step?


Penny Nom lui répond.
An unbelievable story 2000-01-17
Melissa pose la question :
good morning-i am taking a course "math for elementary teachers" and i have a take home problem that i really need help on. here is the question
-the million dollar problem
a recent item in the newspaper described a robbery in which the robber had held up a local bank for 1 million dollars in small bills, had the tellers put the money in a briefcase which he gave them, and fled the scene on foot. is this story believable? explain your answer!

Harley Weston lui répond.
Taxicab geometry 2000-01-16
Jack pose la question :
Im doing an investigation entitled 'taxicab geometry', ive attempted it and have done most of the practical part of it. But i cant seem to see the equation behind it all. please guide me in the right direction.

They provide a regular grid with regular horizontal and vertical lines. The lines are roads and the actual squares are blocks of hoouses/ buildings.

In taxicab geometry the distance between place A & B is worked out by adding together the horizontal and vertical distances. each square is counted as i unit.

Part 1 (I've done this)

A taxix cab firm is based at A. the posistion B is 7 units away from A. investigate all the posistions of B at 7 units. investigate for different distances.

.
.
.

Penny Nom lui répond.
Order of operations 2000-01-16
Dorothy pose la question :
I was wondering if you could tell me where I can get some info. on how to solve the following problem. I was given the answer but I don't know how it is solved.

4+2x(6x2)-5=23


Penny Nom lui répond.
A roll of paper 2000-01-15
Richard pose la question :
I have a roll of paper, wrapped around a corrugate core, whos diameter is 10.750 in. The outer diameter of the roll is approx. 60 in. The thickness of the paper is .014 in. I am trying to find out how much linear feet of paper is left on the roll, given only the diameter of paper remaining on the core.
Chris Fisher and Harley Weston lui répond.
A three digit number 2000-01-13
Manali Shah pose la question :
My son is in 5th grade, he has a math problem. There is three digit number, which is greater than 500, can be divided by 7,9 and 11, but cannot be divided by 2,4,6, and 5.
Harley Weston lui répond.
Algebra 2000-01-13
Tim Merrill pose la question :
"please help me out with these four algebra questions"

  1. Rewrite the following using positive exponents only.

    xy -3
    -------
    x -2

  2. Find the following quotients.

    9a3+3a2+6a
    --------------
    3a


.
.
.

Penny Nom lui répond.
Parallel lines 2000-01-12
Lori pose la question :
Find an equation of the line parallel to the given line containing the given point. x + y = 2; (1,2) We know parallel line have the same slope and we know the answer y = -x + 3.
Penny Nom lui répond.
Addition 2000-01-11
Deanna pose la question :
what is the answer for 20+5+32-3+98
Penny Nom lui répond.
Three dimensional rectangle 2000-01-11
Dennis Murphy pose la question :
I would like to find out the name of a Three dimensional rectangle.
Harley Weston lui répond.
Bar graphs and histograms 2000-01-11
Raeluck pose la question :
What is the difference between a bar graph and a histogram?
Harley Weston lui répond.
Factoring by graphing 2000-01-11
Dylan Kirkwood pose la question :
How can you factor a quadratic equation by graphing it?
Penny Nom lui répond.
Ratios 2000-01-11
Cyndi pose la question :

My name is Cyndi and i am in middle school in the 8th grade. The questions i am about to ask come from my book. My return address is PR_Angel1@yahoo.com

The directions on a can of lemonade mix say to use 8 tablespoons of mix to make 2 quarts of lemonade. Heathcliff wants to make 7 quarts of lemonade. How many tablespoons of mix should he use? and In a recent year, the ratio of men to women in the United States armed forces were about 9 to 1
  1. if there are 90 men in a random group of military personnel, how many women would you expect to find in the group?
  2. in a group of 90 military personnel, how many of them would you expect to be women?
  3. what percent of armed forces personnel were women in that year?

Penny Nom lui répond.
Parallel planes 2000-01-10
Hugo Alvarez pose la question :
When two parallel planes are cut by a third plane, the lines of the intersection are?
Claude Tardif lui répond.
Phone Number Possibilities 2000-01-09
Hamilton Weston pose la question :
How do phone companies arrive at the possible number of phone numbers that can be generated for customers?
Harley Weston lui répond.
Capacitor discharge rate 2000-01-09
Bill Phillips pose la question :
I need to be solve for t in the following rate problem for an electrical capacitor. Vr = E(e^-t/RC), e=nat. log 2.718 raised to the -t/RC power.
Harley Weston lui répond.
Percentages 2000-01-09
Nancy pose la question :

What is the best way for a parent to explain how one calculates percentages?

ie. Commission is $54268. Total Sales $403114.00 from that number how do you calculate the percentage of sales of various expenses.


Penny Nom lui répond.
How many coins is one calculator? 2000-01-09
Mandy Brockmann pose la question :
Tom weighed 1 pen and his calculator with 4 coins. Then he weighed his calculator and 3 pens with 12 coins. How many coins is one calculator?
Claude Tardif lui répond.
Functions 2000-01-06
Tori Morris pose la question :
Consider the function f(x)=x2-3. Which of the following are true?

  1. f(1)>f(0)
  2. f(2)>f(-3)
  3. f(2)=f(-2)
  4. f(-1)=f(3).
More than one answer can be true.

Penny Nom lui répond.
Angles 2000-01-06
Rayna pose la question :
I am doing a presentation report on angles which has to be fun and entertaining as well as educational. I am having problems locating resources on angles that give me ideas of fun entertaining projects. My lecture is to be about 20 minutes long infront of a class of 11th and 12th graders. Please Help if you can.
Claude Tardif and Walter Whiteley lui répond.
Ordering fractions 2000-01-05
A seventh grader pose la question :
I am a middle school student (7th grade) and I was wondering if you could help me with ordering fractions from least to greatest the fractions are 31/12, 2 5/6 and 2 3/4.
Walter Whiteley lui répond.
A probability experiment 2000-01-05
Vanessa pose la question :
Duels in the town of Discretion are rarely fatal. There, each contestant comes at a random moment between 5 a.m. and 6 a.m. on the appointed day and leaves exactly 5 minutes later, honor served, unless his opponent arrives within the time interval and then they fight. What fraction of duels lead to violence?

There must be a minimum number of 100 trials and things like graphing calculator, dice, spinners, and whatever are allowed.
Harley Weston lui répond.

Why study calculus? 2000-01-05
Trlpal pose la question :
I am a high school senior enrolled in a pre-calculus class. Could you tell me what the benefits of taking calculus are and why it would be important to take the class.
Walter Whiteley and Harley Weston lui répond.
Factoring ^6 2000-01-03
Athena pose la question :

my name is Athena and I have a question on factoring: how would you figure this out:

(x6-y6) and (x6+y6)


Penny Nom lui répond.
Y-intercept 2000-01-03
Kayla Boylan pose la question :
How do you use and find the y-intercept?
Penny Nom lui répond.
zero 2000-01-01
Jason pose la question :
What civilization first used zero?
Penny Nom lui répond.
Derive the quadratic equation 2000-01-01
Thuy pose la question :
My teacher asked us this question in which i can't understand when she asked to derive the quadratic equation. What does this mean?
Penny Nom lui répond.
Solving a cubic equation 1999-12-30
Natalia pose la question :
How can I solve:
2 x3 - x2 + x - 2 = 0 ???

Penny Nom lui répond.
Absolute value 1999-12-29
Alex Waller pose la question :
What are some practical applications for absolute value?
Harley Weston lui répond.
Period 1999-12-28
Mahdawi pose la question :
I have attached a diagram of the graph, and I need to find out its period. I really don't understand how to do so, please help!
Harley Weston lui répond.
Parachute Problem 1999-12-28
Stephanie Zinsli pose la question :
A parachutist jumps from an airplane and lands in a square field that is 2 kilometers on each side. In each corner of the field there is a large tree. The parachutist's ropes will get tangled in the tree if she lands within 1/11 kilometer of its trunk. What is the probability that she will land in the field without getting caught in a tree?
Penny Nom lui répond.
Three algebra problems 1999-12-28
Stephanie Branton pose la question :
  1. If P represents the product of all prime numbers less than 1000, what is the value of the unit's digit of P?

  2. Do any real numbers a and b exist such that: ln(a+b)=ln a + ln b? if so, what are they?

  3. Define a function by: f(x)=1/1-x where x is not equal to 0,1. what is f(f(f(a)))?

Harley Weston lui répond.
Graph of a sine function 1999-12-23
Pierre pose la question :
Given;
amplitute:1
period: 540
Phase shift: 60 degree,right

I am ask to right the equation: sin 2/3 (value -60degree)

When I am asked to graph the equation, the period is mixing me up.
Harley Weston lui répond.

Climbing stairs 1999-12-22
Harman Chaudhry pose la question :
Paul, Michelle and Michael all climb up 54 steps. Paul climbs the steps one at a time i.e. 1, 2, 3, etc. Michelle Climbs the stairs 2 at a time i.e. 2, 4, 6, etc. Michael climbs the stairs 3 at a time i.e. 3, 6, 9, etc. How many steps are used by exactly two people?
Penny Nom lui répond.
Specific heat 1999-12-22
Irena pose la question :
In transferring 1260J of heat to water, the temperature of 0.20 kg of mercury falls 50 K. Calculate the specific heat capacity of mercury using the equation C= Q/(m)(delta t)

i know that Q= -1260J because it's loosing heat and m= 0.2kg and since i have to use 'C i have to convert Kelvins into Celsius (i also know that 'C has to be negative since it looses heat)
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Harley Weston lui répond.

Approximations 1999-12-20
Adrian Valc pose la question :
Long-time ago I red an article about surprizing (and in a way frustrating) results in math, for example the limit of a nicely defined infinite series which was believed to be a simple rational number, but later was determined to be a transcendent number that missed the rational value by an incredibly small amount (so for example the limit proved to be 2.75000...00137.. with a lot of 0's in between). I cannot find that article anymore, so i was wondering if you have any such examples, or you can point to any relevant information source?
Chris Fisher lui répond.
Comma as decimal separator 1999-12-18
Franck Menuge pose la question :
Could somebody tell me the origin of the use of a 'comma' as a decimal separator and of a 'dot' for thousands in the French numeric system, ex.1.234,56 Is it only used in France or in other european coutries? Why is it different in the UK?
Patrick Maidorn and Penny Nom lui répond.
The area of a garden 1999-12-17
Jessica Wells pose la question :
Hi My name is Jessica Wells and I am 10 years old. I was hoping you could help me out wityh a question my dad gave me. It is if aq graden is 32cm in diameter and I want to know the area of it what process do I use? He's a math wiz so I need o show him that I'm smart too
Penny Nom lui répond.
Two algebra problems 1999-12-17
Michael Standfest pose la question :
If x+4 is a factor of 2x4+kx3-3kx2+6x-40, find k

and

Prove that n2-n is even for all n, using the proof of contradiction
Penny Nom lui répond.

Proving a trigonometric identitiy 1999-12-17
Ryan pose la question :
I need to figure out how to prove that sec2x + csc2x = sec2x csc2x. I am not sure where to start out with it and whether I should use reciprocal, quotient, or pythagorean.
Penny Nom lui répond.
Logarithms 1999-12-16
Pierre pose la question :
Can you please answer those three question

  1. inverse or the exponential function.

    logx 81 = 4,
    x expo4 = 81,
    x = +or- 4square root 81,
    x = +or- 3
    s.s = {3}
    Why is -3 not acceptable.

  2. .
    .
    .

Harley Weston lui répond.
Rectangular hyperbola 1999-12-15
Aarti Chand pose la question :
Why do they call a rectangular hyperbola, rectangular and where the normal hyperbola looks like a rectangle and the rectangular hyperbola looks like a sqaure?
Chris Fisher lui répond.
A decreasing ellipsoid 1999-12-15
A student instructor pose la question :
The volume of an ellipsoid whose semiaxes are of the lengths a,b,and c is 4/3 *pi*abc. Suppose semiaxes a is changing at a rate of A cm/s , the semiaxes b is changing at B cm/s and the semiaxes c is changing at C cm/s . If the volume of the ellipsoid is decreasing when a=b=c what can you say about A,B,C? Justify.
Harley Weston lui répond.
A model area 1999-12-15
John Ost pose la question :
Hello, I am a college student taking an elementary math course I need if possible assistance to developing an area model 36 x 25 that shows each of the four separate partial products. I must know how to do the computation 36x25 showing each of the four partial products separately, and indicate how each corresponds to the drawing that is required of the area model.
Penny Nom lui répond.
Cutting a carpet 1999-12-15
Heather pose la question :
A rectanglular piece of carpeting is 90 inches long and 90 inches wide. How can the carpet be cut into two pieces of equal sides and shape to cover an area of 100inches? There can only be one cut and no scraps. Please show me how.
Penny Nom lui répond.
.400 in Baseball 1999-12-15
Nieve Nielson pose la question :
I have several questions to ask about the probability of getting a .400 in baseball:
  1. What is the probability of a baseball player hitting a .400 in one game, considering that the hitter is up to bat four times?

  2. What is the probability of a baseball player hitting a .400 in a season, considering that there are 100 games in a season? With the first two questions in mind:

  3. Considering that baseball has been around for about 100 years, about how many people should hit .400 inthat time?

Chris Fisher lui répond.
Fibonacci Numbers 1999-12-15
Gary Nelb pose la question :
I'm doing a project on fibonacci numbers and I'm using different starting values and finding out if different starting values to see whether or not the ratios still get closer to phi. I was wondering, what numbers should I use. Should I use two of the same # like 2 and 2, or numbers like 1 and 2, or even something totally different.
Denis Hanson lui répond.
Two calculus problems 1999-12-13
Alan pose la question :
I have 2 questions that are very new to me, they were included on a quiz and the material was never covered. Our teacher never explained the purpose and detailed explanation of how to solve the problem. Could you help? Thanks.

Question 1:
A ball is falling 30 feet from a light that is 50 feet high. After 1 sec. How fast is the shadow of the ball moving towards the light post. Note that a ball moves according to the formula S=16t^2

Question 2:
How many trapezoids must one use in order for the error to be less than 10^-8 if we want to find the area under the curve Y=1/X from 1 to 2. Find the exact area, Graph the function and use the trap rule for the "N" that you found.


Harley Weston lui répond.

Passing trains 1999-12-10
Nancy pose la question :
Two trains, each of 80 cars, must pass on a single track which has a deadend siding. How can they pass if the siding can only hold a locomotive and 40 cars?

I do not understand this...help. It will be due monday. I thought it would be simple if the siding could hold 80 cars.
Penny Nom lui répond.

Sines & cosine laws 1999-12-10
Pierre Boivin pose la question :
Triangle LMN, angle L=71 degree , LM= 7.2 , MN=8.3 , ln= 5.9

The questiion was to find angle M. Using the cosine law I found the answer to be 44 degree. It is also the book answer. Using the sines law I found the answer to be 42.2 degree. why can't I use the sines law.
Chris Fisher lui répond.

Cubic meters to gallons 1999-12-09
Chris Compton pose la question :
I am trying to convert cubic meters to gallons. Do you have the conversion formula? The problem I am trying to solve is:

59.62 cubic meters to gallons.


Harley Weston lui répond.

Solve for v 1999-12-09
Beth pose la question :
1-3/4(v+2)=-5
Penny Nom lui répond.
A calculus problem 1999-12-08
JT Wilkins pose la question :
These are the questions:

  1. Show that there exists a unique function that meets the following requirements:

    a) f is differentiable everywhere
    b) f(0)= f'(0)= 0
    c) f(x+y)= f(x)+ f(y), for all real values of x,y

  2. Consider the function F: R-->R (All Reals)

    F(x) = 0, for x irrational & 1/q, x=p/q gcd(p,q)=1 q > 0

    a)determine the values x where f is continuous, respectively discontinuous.
    b)determine the values x when f is differentiable and for each of these values compute f'(x).


Penny Nom lui répond.
Percentage change 1999-12-08
Michael Weinberg pose la question :
I am the Laboratory information system supervisor in a hospital. Our computer system calculates the change of specific results to monitor a patient's status. But there is a problem with the calculation in the base code of the program.
If one day the patient has a Blood count of 100 (P for Previous) then the next day the Blood count is 75 (C for current), the computer should calculate the change as -25% using the calculation |P-C|/P= D (D for Delta) and then check for positive or negative by the equation If P>C then D*-1 or If P The program is calculating using the equation: ((P/C)-1)*100 in the above situation this would calculate the Delta as 33.33333% Referenced in a Laboratory manual published before computers were used to calculate the delta changes.
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Penny Nom lui répond.
Advanced Calculus 1999-12-07
Kay pose la question :
Hi, my name is Kay. Please help---these problems are driving me crazzzzy!!!! Your help would be greatly appreciated!
  1. Let a,b be contained in R, a
  2. .
    .
    .

Claude Tardif lui répond.
Inequalities and absolute values 1999-12-07
Austin Cline pose la question :
Solve for x: The absolute value of x-1 is less than or equal to the absolute value of x-2
Harley Weston lui répond.
Mean, median and mode 1999-12-07
J William Morning pose la question :
Using the data values 2,2,10,6,5, determine the median, mode and mean.
Penny Nom lui répond.
Two conics 1999-12-07
Quinn pose la question :
I know the formula to find the axis of symmetry of a conic section (I'm not sure what shape - circle for the first one??) is (-D/2A,-E/2C) but I obviously don't get how to calculate it, because when I check the answer it's wrong, but I'm so close!! For the following equations my teacher suggested to "divide the x term coefficient, D, by the x squared term coefficient before...do the same for y."

2x2+2y2-8x+12y+16=0
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.
.
Penny Nom lui répond.

Bases other than 10 1999-12-06
Garret Magin pose la question :
We are doing a lesson on numbers of other bases than 10. We are working with binary, octal, and Hexadecimal. I was wondering what is used to represent number of different bases other then 16? Does it just continue on with the alphabet and if so what happens when you get to Z. It would be a help if you could answer this because it is really bugging me. And none of the math teachers at my school could let me know.
Claude Tardif and Patrick Maidorn lui répond.
Systems of equations 1999-12-06
Roger Hornbaker pose la question :
I am having problem figuring out x and y solutions.
  1. 5x + y = 4
    3x - y = 4

  2. 3x + 2y = 6
    - 3x + y = 0

Penny Nom lui répond.
order 4+ determinants 1999-12-06
Joe Kron pose la question :
Why is it never shown how to calculate the value of 4x4 (or larger size) deteminants by the diagonal multiply methods that are generally shown for 2x2 and 3x3 determinants? The method I'm talking about is called Cramer's Rule??? Is this method not extensible to order 4+ and if not why not? Anyway the method always shown for order 4+ is called "reduction by minors" which is not the answer to this question.
Walter Whiteley lui répond.
How many 3/5 are in 3/4? 1999-12-06
Whiteny pose la question :
How many 3/5 are in 3/4?
Penny Nom lui répond.
Volume of an ellipsoid 1999-12-06
Michael Nowicki pose la question :
I am a physician at the University of Mississippi. I am trying to compare the size of polyps (abnormal growth of tissue in the colon) between 2 groups of individuals. The department of pathology gives the size as length X width X depth - how do I calculate the volume? Polyps are nearly ovoid in shape.
Walter Whiteley lui répond.
Multinomial coefficients 1999-12-03
Suraj Das pose la question :
Is there a formula for the expansion of (a+b+c) to the nth power? Does it have to do with Pascal's triangle?
Penny Nom lui répond.
The chain rule 1999-12-03
Jennifer Stanley pose la question :
This problem is making me dizzy. I would greatly appreciate a little help!

Express the derivative dy/dx in terms of x.

y=u^2(u-u^4)^3 and u=1/x^2
Harley Weston lui répond.

Log Cancel 1999-12-03
Justin Murray pose la question :
Ok I feel like a goof because I know this and I cant think of an answer But I want to isolate the x in the function y=2^x how do I do this?
Harley Weston lui répond.
Whole numbers 1999-12-02
Patty pose la question :
I'm in a 5th grade class, please explaine what whole numbers are.....
Penny Nom lui répond.
The elimination method 1999-12-02
Jennifer pose la question :
Could I get an answer to this one:

2x+5y=36
3x+2y=32

I have to use the Elimination method, as I already know how to do Substitution. How do I begin and show my work? I'm attempting to eliminate the values for y.
Penny Nom lui répond.

Zero to the zero 1999-12-02
A middle school teacher pose la question :
I am a middle school teacher who is looking for a precise explanation of why zero raised to the zero power is undefined. I am hoping to get an explanation using something other than the fact that diividing by zero is undefined.
Penny Nom lui répond.
Camels and bananas 1999-12-02
Marie Rich pose la question :
Corey Camel's harvest, worth its weight in gold, consists of 3000 bananas. The market place where the stash can be cashed in is 1000 miles away. However, Corey must walk to the market, and can only carry up to 1000 bananas at a time. Furthermore, being a camel, Corey eats one banana during each and every mile she walks (so Corey can never walk anywhere without bananas). How many bananas can Corey get to the market?
Claude Tardif lui répond.
Get rich quick 1999-12-02
Holly Hutson pose la question :
If one cent were placed in an investment that doubles in value every day, what would be the value of the investment at the end of 30 days?
Penny Nom lui répond.
Two calculus problems 1999-12-01
O'Sullivan pose la question :
Question #1 Assume that a snowball melts so that its volume decreases at a rate proportional to its surface area. If it takes three hours for the snowball to decrease to half its original volume, how much longer will it take for the snowball to melt completely? It's under the chain rule section of differentiation if that any help.

I've set up a ratio and tried to find the constant but am stuck.

Question #2 The figure shows a lamp located three units to the right of the y-axis and a shadow created by the elliptical region x^2 + 4y^2 < or= 5. If the point (-5,0) is on the edge of the shadow, how far above the x axis is the lamp located?

The picture shows an x and y axis with only the points -5 and 3 written on the x axis. the lamp is on the upper right quadrant shining down diagonally to the left. There's an ellipse around the origin creating the shadow. It's formula is given as x^2 + 4y^2=5.


Harley Weston lui répond.
Cos x = -1/2 1999-12-01
Pierre Boivin pose la question :
When I factor[ 2cos (square) - 5cos -3], I get (2cos + 1)(cos - 3). 2cos + 1 = 0, 2cos = -1, cos = -0.5,. Using inv cos on calculator, I get 120 degree related angle.

When I graph I get two values, between 90 and 180 degree and between 180 and 270 degrees. How do I find those two values. How do use 120 degree in relation with the x axis.
Penny Nom lui répond.

An area problem 1999-11-29
Vicky Birch pose la question :
The length of a rectangle is three times it's breadth. If the length were 6 meters less, and the breadth were 6 meters more, the rectangle would be a square. Make a mathematical model and solve the resulting equation to find the breadth of the original rectangle. What is the area of the square?
Penny Nom lui répond.
Two candles 1999-11-24
Skip Simpson pose la question :
You have two candles the same length. They are lit at the same time. One burns down in 4 hours; the other in 5 hours. How long does it take before one candle is three times the length of the other candle?
Walter Whiteley lui répond.
The number of city blocks in a country mile 1999-11-24
Gloria Hearst pose la question :
For years my family has had an on going debate on the number of city blocks in a country mile. We vary from a minmum 8 blocks per mile to a maximum of 12 blocks per mile.
Nadine Griffiths and Penny Nom lui répond.
How wide is the well? 1999-11-24
Chris Baranski pose la question :
There is a well and in the well there are 2 sticks one is 2 meters long the other is 3 meters long and they are opposite to each other. They are leaning against the wall of the well. The place where they touch is 1 meter of the bottom of the well. How wide is the well?
Chris Fisher lui répond.
Repeating decimals 1999-11-22
Andrew pose la question :
Is 1.9 repeating the same as 2?
Walter Whiteley lui répond.
Age in minutes 1999-11-21
Mesha Jackson pose la question :
How old would I be in minutes if I were 12
Penny Nom lui répond.
A goofy clock 1999-11-20
Kate pose la question :
While repairing a watch, a jeweler removed the hands and inadvertently replaced the hour hand on the min. spindle and vice versa. he set the hands to read 2:00pm, which was the correct local time when I picked up the watch. A few minutes later, I noticed that the hands were taking goofy positions. What was the first time thereafter that the watch would show the correct local time?
Chris Fisher lui répond.
A matching quiz 1999-11-20
William J. Ricciardi pose la question :
I gave a matching quiz the other day and one of my students got all 9 incorrect. That got me thinking......What is the probability that someone could get all 9 questions incorrect?
Peny Nom lui répond.
Selecting some players 1999-11-20
Korbin Brown pose la question :
Roger Craig, during his term as team manager of the San Francisco Giants, received a strange communication from the team general manager, Al Rosen. Mr. Rosen told him to select 25 players according to this formula: 1/2 of the team had to be outfielders and infielders 1/4 of the team had to be starting pitchers 1/6 of the team had to be relief pitchers 1/8 of the team had to be catchers Roger was a bit confused by Al's request, yet complied anyway. How did he do it?
Claude Tardif lui répond.
Ratios and proportions 1999-11-19
Rebecca pose la question :
I'm not that good of a student and I was woundering if there is a shortcut to ratios and proportion. My 6th grade teach tought all we needed to know. I was just wounder if there was an easier way.
Claude Tardif and Harley Weston lui répond.
Area of a quadrilateral 1999-11-19
Zane Cram pose la question :
I need the formula to calculate the area of an irregular sided rectangle. Each side has a different measurement or length.
Walter Whiteley lui répond.
polynomial functions 1999-11-19
Quinn pose la question :
  1. Without fully factoring the following show that they all have the same zeros:

    I: x4-x2+2x+6
    II: -x4+x2-2x-6
    III: -4x4+4x2-8x-24
    IV: 10x4-10x2+20x+60

  2. When P(x)=x3-3x2+5x+1 and G(x)=x3-2x2-x+10 are each divided by(x-a) the remainders are equal. At what coordinate point does the graph of P(x) intersect G(x)?

Walter Whiteley lui répond.
Critical numbers 1999-11-17
Sarah pose la question :
My question is this:

If f(x)=2x3+4x2-9x+8

and the derivative is f'(x)=6x2+8x-9,

how do I find the critical points if f'(x) is not factorable??
Penny Nom lui répond.

Percent 1999-11-16
Elaine Edwards pose la question :
Can you please tell me what is 75% of $495.00?
Penny Nom lui répond.
Two derivatives 1999-11-16
Gina Renicker pose la question :
The derivative of:

y=e(xlnx) and y=x2arctan(x1/2)
Harley Weston lui répond.

The sixth game 1999-11-16
Stephanie Sprunger pose la question :
Janice scored 18,21,27,16,and 19 points in five basketball games. How many points must she score in the next game to raise her average to 22 points per game?
Penny Nom lui répond.
Domain and Range of a Function 1999-11-14
Michelle Mellott pose la question :
How do you find the range of the following function:

2y2/(y2+5y+6)??

I know the domain is x not equalled to -2, -3. How can one easily find the range?
Harley Weston lui répond.

Estimating the population mean 1999-11-13
John Barekman pose la question :
Statitistics: Estimating the population mean when the standard deviation is known:

I am not sure which n to use in the formula for the confidence interval equation:

x +/- z*(standard deviation/sqrt(n))

If we have data of ten people, and if we have the data of ten sets of ten people each, what is the difference in the n that we use? What is the difference between the standard deviation and the standard error? Are we using the number of sampling means or just the number of samples?
Harley Weston lui répond.

Number sequences 1999-11-11
Justin Schessler pose la question :
I CAN NOT figure out this sequence or how we continue this sequence...

3,2,6,5,15,14,___,___,___
Chris Fisher and Harley Weston lui répond.

Body part measurements 1999-11-10
V Bailey pose la question :
I am a kindergarten teacher and mother of a 6th grader who wants to do a science project on the correlations of body part measurements. We heard this on the radio and it sparked our interest, but now I cannot find any information about it. Examples are: your height is supposed to equal the distance from fingertip to fingertip when your arms are outstretched. Your foot size is supposed to equal the distance from your wrist to your elbow.

Please help me find more information on this topic.
Penny Nom lui répond.

Linear models 1999-11-09
Helen Moreno pose la question :
What is a linear model?
Harley Weston lui répond.
Multiple step problems 1999-11-09
Maria Rainsdon pose la question :
I don't understand how to solve these multiple step problems. I wasn't there when my teacher explained it and I am really lost. Here is one of the probs I don't understand: 3m+6=-m-6.
Penny Nom lui répond.
Parabolic mirrors 1999-11-07
Andy White pose la question :
I am working on a project concerning parabolic mirrors. I need to create a mirror to focus sunlight on a focal point, but I don't know how to do it. Is there some equation that tells where a focal point will be in relation to a parabola?

What is a directrix?
Penny Nom lui répond.

Mean, median and mode 1999-11-06
Rick pose la question :
I have five number places and the mean and median are both "0". The mode is greater than the mean. The sum of the absolute values of all of the numbers is 20. The smallest number is 4 less than the next smallest number. What are the five numbers. (negative integers can be used) All of the numbers are integers.
Penny Nom lui répond.
Crossing number 1999-11-06
Christian pose la question :
The crossing number of a graph G, denoted cr(G) is defined to be the minimum number of (pairwise) crossings of edges among all drawings of the graph in the plane. For example, cr(K5)=1 and cr(K3,3)=1.
What is cr(K7,7)?

I figured out that the answer is 81.

Now I am trying to figure out if K7,7 can be drawn in the plane with less than 81 crossings?

I'm not sure how to approach this one. Other than actually drawing it out and checking by trial and error, I am not sure how to approach this problem. Please help!
Denis Hanson lui répond.

Division/Fractions 1999-11-06
Azmat Hussain pose la question :
Is there a way to explain division by fractions using patterns? For example 3 divided by one half.
Chris Fisher and Penny Nom lui répond.
Nines and ones 1999-11-05
Greg Miller pose la question :
Using the numbers 1, 1, 9, 9, only once each, how can I create an expression that equals 10 using only the basic functions of addition, subtraction, multiplication, division, and/or parentheses?
Claude Tardif lui répond.
Three numbers 1999-11-03
Walter pose la question :
Three whole numbers , when added two at a time,yield the sums 75, 111, and 128.

Find the smallest of these three whole #'s.
Penny Nom lui répond.

Transforming a triangle 1999-11-02
Wilder Maldonado pose la question :
The height, H, of a triangle is increased by a lenth M, How much must be subtracted from the corresponding base,b, so that the area of the new triangle is one-half that of the original triangle.
Penny Nom lui répond.
Trolls and Gargoyles 1999-11-02
TexGrimm pose la question :
How can you seat 6 monsters - 3 Trolls and 3 Gargoyles- at a circular table if the trolls look alike and the gargoyles look alike? Does your formula work for 9 monsters - 4 trolls and 5 gargoyles?
Penny Nom lui répond.
Inverses of functions 1999-11-01
Leanne Hickey pose la question :
Let f(x) = 2x2 -3x + 2. Find f-1(4) given the fact that f(2) = 4. So the question is finding the inverse of 4, he said it's easier than it looks.
Penny Nom lui répond.
Powers of zero 1999-10-31
Salina Young pose la question :
Hello! I have two questions to ask about the power of "0".

First, what is the value of "0' to the power of "0"? And why?

Second, what is the value of "0" to the power of "2" or '3" etc? And why?

Thank you for your help.
Walter Whiteley and Harley Weston lui répond.

Area of a circle and an inequality 1999-10-30
Adam Anderson pose la question :
I have two problems.

The first: prove that the area of a cirlce is pi times radius squared without using calculus.

The second: show that ln(x) < x - 1 for all x > 0.


Harley Weston lui répond.

A pictograph 1999-10-28
Ali pose la question :
Please tell me how to make a pictograph.I am 2 grade student.
Penny Nom lui répond.
Ben's observation 1999-10-28
Emily Nghiem and Ben Rose pose la question :
As a teacher at a school called Educere in Houston, I have a ninth-grade student who discovered the following shortcut last year as an eight-grader. What he noticed is that given any two consecutive integers (or n and n+1 for any rational number greater than or equal to 2), the difference between their squares was equal to the sum of the two numbers.
.
.

Chris Fisher and Penny Nom lui répond.
Calculating a square root 1999-10-28
Jonathan pose la question :
What is the formula for calculating a square root?
Penny Nom lui répond.
Clockwise or Counterclockwise? 1999-10-27
Tim pose la question :
A particle moves around the circle x2 + y2 = 1 with an x-velocity component dx/dt = y
  1. Find dy/dt

  2. Does the particle travel clockwise or counterclockwise around the circle? Why?

Harley Weston lui répond.
Derivatives with logs 1999-10-26
Kate pose la question :
What is the derivative of 5 to the 5x-2 at x equals 0.8?
Harley Weston lui répond.
Order of operations 1999-10-25
Garrett pose la question :
99*(57+76)*9-1085/9
Penny Nom lui répond.
-log(a) 1999-10-22
Brenda Miskimmin pose la question :
I need to know the mercury concentration in mg/L or ng/L for the following:

-log M (Hg) = 8.5

where mw of Hg=200.59

(it's the negative sign in front of log that confuses me).
Harley Weston lui répond.

An odd number of factors 1999-10-22
Melissa pose la question :
What is the common name used for numbers that have an odd number of factors? What is the least positive integer that has exactly 13 factors?
Penny Nom lui répond.
Cutting a board into 8 equal pieces 1999-10-21
Brittany pose la question :
Jamie wanted a board cut into 8 equal pieces. The Lucas Lumber Co. charges 60 cents for cutting a board into 4 equal pieces. How much will it charge for cutting Jamie's board?
Claude Tardif lui répond.
0! + 1! + 2! + 3! + ... + 2000! 1999-10-21
Melissa pose la question :
My name is melissa. I am a 9th grade student I am having trouble finding out how to do this: What is the tens digit of 0! + 1! + 2! + 3! + ... + 2000! I know how to find these, but my calculator cant go any higher than 69! Is there any way i can do this problem?
Penny Nom lui répond.
Going to the movies 1999-10-21
Gayla Werry pose la question :
You have $1.00 to take 100 people to the movies. It costs: 1 cent for 10 children, 3 cents for each woman, 5 cents for each man. You have to take at least one of each category of people. Your answer has to add up to exactly 100 people and exactly $1.00. How many men, women, and children can you take?
Penny Nom lui répond.
|6-2x|<4 1999-10-20
Tchilco pose la question :
Solve |6-2x|<4
Harley Weston lui répond.
Piecewise functions. 1999-10-20
Jenny pose la question :
How do you figure out a piecewise function by hand?

e.x.
( 2x (if x is not equal to 0)
f(x)=<
( 0 (if x is not equal to 0)
Harley Weston lui répond.

How many squares are on a chessboard? 1999-10-20
Tchilco pose la question :
How many squares are on a chessboard?
Penny Nom and Claude Tardif lui répond.
Broken line graphs 1999-10-19
Lori Samara, Kristi Cameron and the 4th grade students pose la question :
Students in Ms. Cameron's grade 4 class were wondering if a broken line can be used anywhere in the range on the y - axis when creating a broken line graph? They understand that the broken line can be used at the 0 on the broken line but what if there is a large gap in the data from 100 - 200? What do we do? The text book and mathematics dictionary do not answer these questions.
Penny Nom lui répond.
l'Hospital's Rule 1999-10-18
Yannick Gigandet pose la question :
How can I solve these two limits :
  1. lim when n approches 1 of n[a1/n -1]

  2. lim when x approches 0 of (eax - ebx) / x
Thanks for the answer!

Harley Weston lui répond.
Working Backwards 1999-10-16
Linda pose la question :
I am having problems finding examples of problems that require "Working Backwards" used as a strategy for solving. We are required to give a presentation on Monday, October 25, 1999 in our school districts math class. We are trying to become better problem solvers and how to teach problem solving in the elementary classroom. Help! I can't find anything in my web searches.
Penny Nom lui répond.
An equivalent decimal 1999-10-14
Cheryl Wendlandt pose la question :
I have a question in my book that is one and five sixths and you are to put them in an equivalent decimal. I'm sick at home or I would be able to ask my instructor. I would appreciate any help.
Penny Nom lui répond.
(-5)^2, -5^2 and -(5)^2 1999-10-13
Jennifer Brown pose la question :
What is the difference between the following problems:

(-5)2, -52 and -(5)2

Our text book (Beginning Algebra, fourth edition, published by McGraw Hill, by Streeter, Huthison and Hoetzle) says the second and third problem are exactly the same. I don't see how that can be. Is there a mathematical rule that explains this?
Penny Nom lui répond.

Find the missing numbers 1999-10-12
Bonnie pose la question :
I must find the missing numbers and function rules

noutput
710
1220
3940
2430
16b
87c

we are totally confused can someone help
Denis Hanson lui répond.

A famous mathematician 1999-10-12
Yvette Perez pose la question :
Another way to write 3/15. Remove 0 add a line, unscramble, you have the name of a famous mathematician.
Claude Tardif lui répond.
Isosceles triangles 1999-10-12
Amber pose la question :
In defining the types of triangles, our class was stumped by a question asked by one of the student. Maybe you could help. The definition of an equilateral triangle is a triangle with three congruent sides. The definiton of an isosceles triangle is a triangle with at LEAST two congruent sides. The question is, if an isosceles triangle only requires at Least two of the sides to be congruent, could an equilateral triangle be called an isosceles triangle?
Penny Nom, Walter Whiteley and Chris Fisher lui répond.
Solving using logs 1999-10-11
Rich Bolton pose la question :
Here's my question:

$541.39(1+i)15=784.09

Can you please show me how to do this?
Penny Nom lui répond.

Women in Trig 1999-10-11
Sandra Mills pose la question :
I am looking for some information about women who have contributed to the discipline of trigonometry. In addition to this I have been asked to choose a subject pertaining to Roman times for my Roman and American Lit class. I wanted to do a project and presentation related to mathematics, but could use some suggestions-- maybe how mathematics were applied as in engineering and the structure of the Roman buildings. Could you please provide some information about the history of mathematics and it's applications in Roman times. I am also open to any other suggestions for topics.
Chris Fisher lui répond.
Equations with fractions 1999-10-10
Lori pose la question :
I'm a secondary student. How would you figure out a problem such as t-2/t =14/3t - 1/3. The book gave one example but it is really easy. The work YOU have to do is totally different. You don't have to tell me the answer just how to do such problems like these.
Penny Nom lui répond.
Length of a line 1999-10-10
Dagmara Sarudi pose la question :
My question has to do with the length of a diagonal. This problem came up when I thought about the shortest distance between two points, for example walking from one point to another in my neighborhood. I can choose a zig zag route and assuming the blocks I walk are exactly the same length, it shouldn't matter what route I took, the distance I travel should still be the same when I reached my goal. If, on the other hand I could travel in a diagonal line, the distance would be shorter. But what if, in my zig zag motion, the sections get so small the route approaches a diagonal. Shouldn't it be that each separate section added together equals the value of the two original sides? Or would it suddenly equal the value of the diagonal (which, of course was shorter than the two sides added together)?
What gives?


Chris Fisher and Harley Weston lui répond.

Two Quadratics 1999-10-08
Jason On pose la question :
Solve the following equations,expressing solutions in the form p + iq.
  1. sqr(x) + 2x - 1 = 0,
  2. sqr(x) + 2x - 3 = 0.

Harley Weston lui répond.
A sum of two squares 1999-10-08
Marksmen pose la question :
what is the smallest whole number that can be written two ways as a sum of two different perfect squares? i.e.11squared plus 3 squared is 121+ 9=130 and7 squared + 9squared=49 +81= 130. Are there any smaller? I am stumped!
Claude Tardif lui répond.
sin x = x/10 1999-10-07
Amandeep Grover pose la question :
Solve the equation sin x = x/10
Harley Weston lui répond.
A trig limit 1999-10-06
Yannick Gigandet pose la question :
What is the limit, as x approaches pi/3, of (1-2cosx) / sin(x-(pi/3)) ?
Penny Nom lui répond.
Palindrome 1999-10-06
Chris Ware pose la question :
What is a non paladromic number?
Claude Tardif lui répond.
Logic and mathematical logic 1999-10-06
Polly Mackenzie pose la question :
What is the difference between logic and math logic?
Walter Whiteley lui répond.
A googol 1999-10-06
Kevin Brennan pose la question :
describe to me a guegoll is that how u spell it?

it sounds like that
Penny Nom lui répond.

Common factors 1999-10-06
Tommygirl98 pose la question :
Ok I have a question about common factoring I'm not to sure if you could help me but it's worth a try here it goes. Ok I have a test on Friday and i'm having trouble understanding how to do it here's an example,

Factor,
-10 + 2b how do you do it and what do they mean by factor?
Penny Nom lui répond.

The circumference of a circle 1999-10-05
Mara Frost pose la question :
what is the formula to find the circumference of a circle, or if there is no formula, how do you find the circumference of a circle?
Penny Nom lui répond.
towers of cubes 1999-10-05
Sanker pose la question :
I need help to solve this Rules for bulding towers of cubes
rule 1 The number of cubes on the bottom layer is always one less than the number of squares on the grid
rule 2 Each new layer is made with one cube less than the layer underneath it.
  1. Investigate how many different arrangements there are of 4 cubes on top of 5 cubes on a two by three grid

  2. investigate the number of different arrangements of six cubes on top of seven cubes on a two by four grid

  3. investigate the relation between the number of arrangements of cubes and the size of the grid
    • when there are two layers of cubes
    • when there are more than two layers of cubes

Walter Whiteley lui répond.
Regular and irregular shapes 1999-10-03
Samuel Tighe pose la question :
What is the difference between a regular shape and an irregular shape? Are a rectangle and a triangle regular or irregular shapes?
Walter Whiteley lui répond.
Percentage increase 1999-10-03
Ann Allen pose la question :
I am a a student in the 12th grade. I need to know how to calclulate the following: A percentage increase from 2.0% to 9.5% is what percentage?
Harley Weston lui répond.
Two limits 1999-10-02
Jennifer pose la question :
How do I find

lim (1-cosx)/(x^2) as x-> 0

and

lim (tan3x)/x as x->0
Harley Weston lui répond.

A donkey and his carrots - part 2 1999-10-02
Sarah Klink and Brenda Gamble pose la question :
Does anyone know the solution of the donkey who had to carry 3000 carrots to the market which was 1000 miles away? The donkey can only carry 1000 carrots at a time and he eats one carrot every mile he walks but this is only when he is carrying carrots. How many carrots can get to the market with the donkey carrying them?
Claude Tardif lui répond.
Temperatures 1999-09-27
Eula pose la question :
How do you cahnge farenheit degrees to celsius degrees?
Penny Nom lui répond.
Dollar Bills 1999-09-27
NRQT pose la question :
Why are 1999 American dollar bills worth more than 1997 American dollars bills? This has to be put into a mathematical problem???
Penny Nom and Claude Tardif lui répond.
Jose and Arthur 1999-09-26
Joel Hammer pose la question :
Jose can run around the track in 40 seconds. Arthur runs with Jose but in the opposite direction. They meet every 15 second. How long will it take Arthur to make one trip around the track?
Denis Hanson lui répond.
Trigonometry history 1999-09-25
Nikki pose la question :
What is trigonmetry ? Who invented it ? What is it's purpose ? And anything else that you can tell me that is related to Trigometry.
Chris Fisher lui répond.
Two 12-sided polygons 1999-09-25
Kelly Boulton pose la question :
Two 12-sided polygons are similar. A side of the larger polygon is 3 times as long as the corresponding side of the smaller polygon. wHAT IS the ratio of the area of the larger polygon to the area of the smaller polygon.
Walter Whiteley lui répond.
Intercepts 1999-09-24
Cassandra pose la question :
My book says to find where the X and Y intercept, i dont understand who to do this problem. Can you please help here is the problem. it didnt quite explain the instructions.
Penny Nom lui répond.
A fraction problem 1999-09-23
TruRed pose la question :
Seven ninths divided by a negative 3.Could you pleas answer my question and go step by step.
Penny Nom lui répond.
Percentages 1999-09-23
Pete Cornejo pose la question :
Hello, I was wondering if you could help me with a question? Yesterday my daughter came to me and asked if I could help her solve these three problems.
  1. 18 percent of 25 is what?

  2. 18 percent is what of 25?

  3. 25 is what percent of 18?

Walter Whiteley lui répond.
English to french maths words translators 1999-09-22
Steph Keeley pose la question :
Can you foward be any information re English to french maths words translators, as i am having problems finding one.
Penny Nom lui répond.
-8*-(-5a)=15 1999-09-22
Shelby pose la question :
-8*-(-5a)=15

i cannot get this question!! please help me!!
Harley Weston lui répond.

Predictions 1999-09-22
Joesph Dana pose la question :
How do u find the results of an unbiased sample of 100 students that are shown on the table. For example the school has a total of 1,150 students prdict how many students would chose cereal(46) pancakes(15) eggs(20) and sandwich(19)
Haeley Weston lui répond.
Numbers with the digit 2 in 1...1000 1999-09-20
Jessica pose la question :
Is there a trick to finding out how many numbers containing the digit two is there from 1 to 1000?
Walter Whiteley lui répond.
Distance between the windows 1999-09-19
Lawrence pose la question :
An observer on level ground is at distance d from a building. The angles of elevation to the bottom of the windows on the second and third floors are a and b respectively. Find the distance h between the bottoms of the windows in terms of a b and d
Harley Weston lui répond.
Fractions, percents and decimals 1999-09-19
Sue Farr pose la question :
My son is in 5th grade, and I can't seem to find any papers that have a simple explanation of how to convert decimals into fractions, percents into decimals, and vice-versa.
Harley Weston lui répond.
Magic Square 1999-09-18
Nick Grundberg pose la question :
Using the this square, fill in the squares using the numbers 1 through 9 just once to make all the sums equal in all directions, across, down, and diagonally.

Then tell what the sum of the magic square equals.
Penny Nom lui répond.

Repeating decimals 1999-09-18
Kavoos Bybordi pose la question :
I dont know how to change a reccuring decimal to a fraction please could you tell me the method.
Penny Nom lui répond.
Surface area of a cone 1999-09-18
Frothy pose la question :
I don't understand how to find the surface area of a cone. The height is 12cm and the radius is 5cm.
Walter Whiteley lui répond.
The greatest possible difference 1999-09-17
Denea Hugunin pose la question :
Use each of the digits 1 to 5 once to make a 2 digit number and a three digit number that the greatest possible difference.
Penny Nom lui répond.
2 to the x and x squared 1999-09-17
John pose la question :
For what values of x is 2 to the exponent x greater than x squared?
Harely Weston lui répond.
Square roots without a calculator 1999-09-14
Josh Weiner pose la question :
Is there any way to find out a square root without a calculator?
Harley Weston lui répond.
Bob and his dad 1999-09-14
Yvette pose la question :
"Bobs dad is 27 yrs older then Bob. The sum of their ages 5 yrs ago was 45 yrs. How old is Bob now?"
Penny Nom lui répond.
Stem and Leaf Plot 1999-09-14
Jeanette Sovick pose la question :
My 5th grade son brought home a math paper, the title of which reads, Reading Stem-and-Leaf Plots...can you explain this so I can explain it to him...There is no book, his teacher just sent this practice sheet home for him to complete and I have no clue!
Penny Nom lui répond.
Six toothpicks 1999-09-14
Maddie pose la question :
The book asks: Using 6 toothpicks represent the number 17. I am studying expressions to represent a number. ex.) (2+4)4x4=96.
Penny Nom lui répond.
Two Jugs 1999-09-14
Kynadi Kemp pose la question :
If you have and 8 liter and a 3 liter jug and you want exactly 4 liters how do you get it if there is a water hose near by but thats all you have to get the 4 liters how do you do it ?????
Penny Nom lui répond.
Help with three mathematicans! 1999-09-14
Ashley Tacheira pose la question :
I am a sophomore in high school and have been assigned a research paper on over thirty mathematicians. I was able to find information on all but three. I need to know the birth and death dates and major contributions of these three mathematicians. Any suggestions on where to look would be appreciated. George Stigler, T.C. Koopmans and Thomas Guthrie are the three that I cannot seem to find.
Chris Fisher lui répond.
Bales of hay 1999-09-13
Ivy pose la question :
You are given 5 bales of hay. Two bales are weighed at a time, which equal the following weights:
110, 112, 113,114,115,116,117,118,120,121. What does each individual bale weigh?

Harley Weston lui répond.
Inductive reasoning pattern 1999-09-13
Greg Walsh pose la question :
What are the next 2 rows of the pattern?

3
13
1113
3113
2123
112213
312213
Walter Whileley lui répond.

Roman Numerals 1999-09-13
April pose la question :
Write MCDXCVII in arabic numbers
Penny Nom lui répond.
Spreading a rumor 1999-09-13
Bornstar14 pose la question :
There is someone who wants to spread a rumor within 7 days to 250,000,000 people. he wants to know how many people he should tell on the first day (assuming the rumor is passed by everyone who was told to the same amount of people) so that everyone knows on the 7th day. What I did is the 7th root of 250,000,000. this answer is not possible unless rounded. is it okay for the number to be approximate?
Penny Nom lui répond.
Rolling Circles 1999-09-12
Craig Ellis pose la question :
We have a circle of radius 3. inside the circle and tangent to the circle of radius 3 at one point is a circleof radius 1. The question is if we could roll the smaller circle around the inside of the larger circle how many revolutions would it take to get around to where we started.
Chris Fisher and Walter Whiteley lui répond.
2,5,8,1 yields 24 1999-09-12
Terry Hill pose la question :
I was wondering how do I make the numbers 2,5,8,and 1 equal 24?
Penny Nom lui répond.
How many went to the game? 1999-09-09
Lisa Schmidt pose la question :
If 3/4 more students went to the game than actually did go to the game, 25% of all students in the entire school would have gone. What fraction of students in the entire school went to the game?
Harley Weston lui répond.
Degrees and triangles 1999-09-09
Sandra Mills pose la question :
Are there any triangles which are not 180 degrees?

I am also in need of information on the history of degree measure for an angle.
Walter Whiteley lui répond.

Four fours 1999-09-09
Roger pose la question :
I need help with a math problem my child asked me about I guess in her 7th grade math class they were told to come up with a answer from 1-10 only using four 4's and she got stuck on the problem that needs to be equal to ten, she asked me and I couldn't help her it's sad so if you could give me the problem and and answer so i could explain it to her I would really appreciate it.
Penny Nom lui répond.
Using Factoring in Problem Solving 1999-09-09
Lori pose la question :
I have a problem with a problem. The Problem is....The sum of the squares of two consecutive positive even integers is 340. Find the integers.
Penny Nom lui répond.
Infinity 1999-09-08
Richard Tracy pose la question :
In order to transverse from point A to point B one must first cross the halfway point (C). Additionally....One must also pass another halfway point labeled (D) in order to get to the halfway point of (C). There is also point (E) which is the halfway point between A and D. We have to assume that there are an infinite amount of halfway points points between (A) and (B). My understanding of infinity is something that goes on forever. But how can one expect to traverse over infinity in a finite amount of time? Will we never reach (B)?
Walter Whiteley lui répond.
Who is right 1999-09-04
rf, k, p and uncle a pose la question :
Good morning. Could you please, help us resolve and by the way, confirm "who is right"... regarding the solution of this problem: - a piece of metal is 6 in. wide by 2 in. in height and weights 500 pounds... - what is the weight of a piece made of same metal, 5 in. wide by 1 3/4 in in height? Could you please supply the "formula".

Regards, rf, k, p and uncle a.
Penny Nom lui répond.

Towers of Hanoi 1999-09-03
Jeni pose la question :
In the puzzle called the Towers of Hanoi there are three peg and you are asked to move the rings from one peg and stack them in order on another peg. You can make as many moves as you want, but each move must consist of moving exactly one ring. Moreover, no ring may be placed on top of a smaller ring. The minimum number of moves required to move n rings is 1 for 1, 3 for 2 rings, 7 for 3 rings, 15 for 4 rings, and 31 for 5 rings. Find a formula for this sequence. What is the minimum number of moves required to move 6 rings?
Penny Nom lui répond.
Is zero positive? 1999-09-03
Shah pose la question :
Is zero a positive integer?
Penny Nom lui répond.
Y2K? 1999-09-03
Mike Putzakulish pose la question :
In Y2K, the "K" stands for thousand, but where did the "K" come from? I know it's not a Roman Numeral, but what is it??
Chris Fisher and Harley Weston lui répond.
Notation 1999-09-03
Judy Gray pose la question :
My name is Judy Gray. I guess the level on this would be about middle school, and I am an other!! I've been out of school for alot of years. I have a couple of questions, I guess.
  1. What does an equal (=) with a slash through it mean? I put intersects, but I think I'm wrong.

  2. What is the symbol of a small n? Only the symbol is wider. Example: If A = {1.2} B = {2,3} then what is A (n) B? Can you make sense out of that?

  3. What is the equation of the y-axis?

Penny Nom lui répond.
The three jugs problem 1999-09-02
Kent Lane pose la question :
I wonder if you could help me figure out this secondary Discrete Math Problem. I cannot figure out where this comes from.

Here's the question:

You have three containers. Container 1 is a three (3) liter container. Container 2 is a five (5) liter container. Container 3 is an eight (8) liter container that is full of liquid. The goal is to get 4 liters in one of the containers.

Stipulations: There are no marks on the containers to measure out the liquid.

All you know is that 1 is 3 l., 2 is 5 l., and 3 is 8 l. full of liquid.
Chris Fisher lui répond.

Division by zero 1999-09-02
Joshua B. Mariano pose la question :
Why can't I divide a number by zero. When I put in my calculater 0 divided by 7 it equals 0. But when I put 7 divided by zero my calculater say's error. Why can't this be solved? What is the answer? Is there a paper on it? Help?
Walter Whiteley lui répond.
A double negative 1999-09-01
Dennis pose la question :
If b = -2 what does -b = ? As in (a + 8.5) - [(-b) + |c|] a = 1.5, c = -1.7
Penny Nom lui répond.
A Multiple Choice Test 1999-08-31
Cintra Ramnarine pose la question :
I have ten questions. There are two multiple choice answers to each question. What are the chances of answering all questions correctly.
Harley Weston lui répond.
Intercepts 1999-08-29
Sally Rickerson pose la question :
I am looking for any intecepts. How do I solve: y=x^2 square root of (9-x^2)
Harley Weston lui répond.
The Bellhop Problem 1999-08-29
Gerard O'Neill pose la question :
Three fellows going to a Math Conference book into a motel. "That will be $30.00" says the bellhop. Each fellow gives $10.00 and they go off to their room. The manager enters and says "That was a $25.00 room. Go and give them $5.00 back."
The bellhop heads off but thinks....."how am I going to split $5.00 between 3 fellows? Hey I will keep two dollars and give each guy a dollar." He does just that.......each fellow now paid $9.00 and the bellhop kept two. 3 X 9= 27 plus the bellhops two = $29.00 Where is the missing dollar?

Harley Weston lui répond.
A Trigonometry Question 1999-08-28
Diane Simms pose la question :
My question is can the following be factored. I am a teacher who needs the factors to this right away. 2 Sin2X + 2 SinX CosX - 1= 0
Harley Weston lui répond.
Invert and multiply 1999-08-28
Debbie Walter pose la question :
I have another question please, WHY do we invert and multiply when dividing fractions? I know that's what we do but WHY? What is the reasoning behind it?
Penny Nom lui répond.
Crossing the Bridge 1999-08-27
Debbie Walter pose la question :
If you have four people who need to cross a bridge in the dark with only one flashlight and only two of them can cross at a time and their speeds of crossing are as follows:
  • one person can cross it in one minute
  • one person can cross it in two minutes
  • one person can cross it in five minutes
  • and the slowest person can cross it in ten minutes
what is the shortest amount of time it would take to get all four across the bridge?

Penny Nom lui répond.
The sum of the cubes is the square of the sum 1999-08-25
Bernard Yuen pose la question :
How to prove 13 + 23 + 33 + 43 + ... n3 is equal to (1+2+3+...n)2? (for n is positive integer)
Harley Weston lui répond.
A gazillion 1999-08-21
Leah pose la question :
Does a gazillion really exist?
Penny Nom lui répond.
Division by a negative 1999-08-19
Sangeeta B. pose la question :
56/-8
Penny Nom lui répond.
Why is slope designated m? 1999-08-18
Peter Komlos pose la question :
Why is the slope of a line is designated by the letter "m"?
Penny Nom lui répond.
Perimeter 1999-08-15
Mel Nordan pose la question :
The length of a rectangle is IS 3 1/2 times its width. Its perimeter is 108cm. Find its length and width. Choices for the width: 12,18,24
Penny Nom lui répond.
111...1222...2 1999-08-11
Brad Goorman pose la question :
Let N = 111...1222...2, where there are 1999 digits of 1 followed by 1999 digits of 2.
Express N as the product of four integers, each of them greater than 1.

Penny Nom lui répond.
Parametric Equations 1999-08-06
Nicholas Lawton pose la question :
Show that an equation of the normal to the curve with parametric equations x=ct y=c/t t not equal to 0, at the point (cp, c/p) is :

y-c/p=xp^2-cp^3
Harley Weston lui répond.

From an airport control tower 1999-08-04
Pammy pose la question :
Hi I am a 30 yo mature age student doing my HSC but am having difficulty understanding this, if you can help me.

From an airport control tower, a Cessna bears 023 degrees T and is 27km away. At the same time, a Boeing 767 bears 051 degrees T and is 61km from the tower. Both planes are at the same height.

i) What is the size of angle ATB?

ii) Using the cosine rule to calculate the distance the planes are apart, to nearest kilometre.

I figured out and drew the triangular diagram but can't figure out the rest and which formula to use. sorry about this, thankyou kindly
Harley Weston lui répond.

Cognitive development as related to learning mathematics 1999-08-04
Chris Ahlman pose la question :
I am doing an independent study for my Math theory course at Evergreen State College, WA. I am looking into teaching Math to elementary students "as a language". I need information on cognitive development to tie to this idea of language development. I only know of Piaget. There must be others who are more recent. Can you help?
Walter Whiteley lui répond.
Cleaning an Ellipse 1999-07-29
Mark Salter pose la question :
Hello hope some one can help. We need to clean an elipse and then paint it. We need to know the square foot of the job and the job is an elipse which rises 2 ft. is 12 ft wide and is 36 ft long.
Harley Weston lui répond.
Geometry 1999-07-29
Jessica pose la question :
How do you even do Geometry. Like what do you need to learn first and like a step by step plan.I realy need help I need it before school starts PLEASE!!!!!!!!!
Walter Whiteley lui répond.
A difference of squares problem. 1999-07-24
Michael and Stephanie Bixler pose la question :
If you have the equation x= n2 - m2 (ie 40= 72-32= 49-9) x must = a positive number

1) which squared numbers work as n and m
2) how does it work
3) if my teacher gave me the number for x; how could I figure out this problem
Harley Weston lui répond.

A calculus problem 1999-07-22
Nicholas Lawton pose la question :
The curve y= e^x(px^2+qx+r) is such that the tangents at x=1 and x=3 are parallel to the x-axis. the point (0,9) is on the curve. Find the values of p,q and r.
Harley Weston lui répond.
Infinity Symbol 1999-07-13
Mark E. Kelly pose la question :
There is a symbol that looks like a sideways 8 that is used to represent infinity. Does it have a name?
Doug Farenick and Penny Nom lui répond.
Standard Deviation 1999-07-11
Anthony Fama pose la question :
I have seen several answers to this question: If one standard deviation represents 68% of the population, what does two, three, four and five sigma [std deviation] represent? As stated, I have seen several different answers and thus, the impetus for my question.
Harley Weston lui répond.
The number of acres in a square mile 1999-07-09
Rita Murphy pose la question :
What is the # of acres in square mile
Harley Weston lui répond.
An Acre. 1999-07-02
Walker Runnels pose la question :
What is the outside measurements of an acre?
(ie. x ft. X x ft.)

Penny Nom lui répond.
Compound Interest 1999-07-01
Kim Palmer pose la question :
In early 1997, my son borrowed $4831 at 7.5%. He has made 30 monthly payments of $130 each. He is now in a position to pay off the balance. What is his remaining principal?
Penny Nom lui répond.
The shortest ladder 1999-06-26
Nicholas pose la question :
A vertical wall, 2.7m high, runs parallel to the wall of a house and is at a horizontal distance of 6.4m from the house. An extending ladder is placed to rest on the top B of the wall with one end C against the house and the other end, A, resting on horizontal ground. The points A, B, and C are in a vertical plane at right angles to the wall and the ladder makes an angle@, where 0<@
Harley Weston lui répond.
Scheduling Meetings 1999-06-25
Beth Carver pose la question :
We have 6 groups meeting at three different places simultaneously. The meetings take place once a month each year. Is there a way to have each group meet with each of the other groups at least twice in a year, four times in each place?
Chris Fisher and Harley Weston lui répond.
Computer use in mathematics classrooms. 1999-06-23
Rosemary Greer pose la question :
Can you give me any information, either articles or the names of books, concerning the use of computers in the math classroom?
Lillian Perivolaris lui répond.
Staying under budget. 1999-06-22
Chris pose la question :
If I had $147.69 and I had to buy 200 bannas at $.46 & 100 potatos at $.42 each how do I stay under my buget
Penny Nom lui répond.
Sin 4A 1999-06-22
Ryan Cochrane pose la question :
If sinA = 4/5, and A is a first quadrant angle, find sin4A
Harley Weston lui répond.
A Weighty Problem 1999-06-17
A parent pose la question :
When using a balance scale, weights can be placed on either side of the scale. For example, if a 10 pound weight provides a counter balance to an object and a 7 pound weight, then the object must weigh 3 pounds. What four weights can be used to weigh objects of 1, 2, 3 ... 38, 39, 40 pounds?
Penny Nom lui répond.
Even and Odd Function 1999-06-17
Kent pose la question :
There is one function with the domain of all real numbers that is both even and odd. Please give me the answer to this question before I go insane.
Penny Nom lui répond.
Liquid capacity 1999-06-15
Bernard Antill pose la question :
Would you please tell me how many litres of water in a swimming pool that is 24 feet long, 16 feet wide & 4 feet deep. I would appreciate you showing the formula for this calculation. I am a 74 year old male and I cannot find a formula in which I have any faith! I would also appreciate the answer in Imperial gallons.
Penny Nom lui répond.
Slopes of curved lines 1999-06-09
Stephen Ehrler pose la question :
When one plots the graphs of y=2x, y=3x, y=xx When each of these graphs pass through point (0,1) do they have the same slope? I know they are different lines but is it possable that they have the same slope at point (0,1).
Harley Weston lui répond.
Measuring the fourth dimension 1999-06-07
Suzanne Hall pose la question :
Hi! The other day, two of my students asked a very interesting question: Is the fourth dimension measured with hypercubes? Their reasoning went like this: Lines are 1D and are measured with line segments, which are part of a line. Planes are 2D and are measured with squares, which are part of a plane. Space is 3D and is measured with cubes, which are part of space. So, logically, hypercubes would be used to measure the fourth dimension.
Chris Fisher lui répond.
A trig problem 1999-06-03
Stu Barnes pose la question :
cos(theta) / 1+ sin(theta)=sec(theta)-tan(theta)

I've being having trouble with this one on my correspondance course.
Harley Weston lui répond.

The three cousins 1999-06-01
Irena pose la question :
I have three cousins on my dad's side. The product of their ages is 84. Next year the youngest will be 1/4 the age of the middle cousin. In 2 years from now, the oldest will be twice the current age of the middle. What is the age of my oldest cousin?
Harley Weston lui répond.
A problem with powers 1999-06-01
Bill pose la question :
solve for the variable:

5-x = 25x+6
Penny Nom lui répond.

How to carpet a room 1999-05-31
Appleby pose la question :
A room which is 9X12 is to be covered with carpet but the carpet has been provided in one 8X1 piece and one 10X10 piece. The larger piece is to be cut into two pieces so that the room can be covered in carpet.
Stacey Wagner lui répond.
An Invalid Argument 1999-05-31
Rod Redding pose la question :
Can an invalid argument have a true conclusion? If yes then why?
Walter Whiteley lui répond.
Graphing a linear equation 1999-05-27
Dylan Bradley pose la question :
Im in Grade ten and am doing linear equations, I cann't figure out how to make a chart for questions like y = -2x + 3
Penny Nom lui répond.
A circle in a square 1999-05-26
Jose V Peris pose la question :
A circle is inscribed in a square. The circumference of the circle is increasing at a constant rate of 6 inches per second. As the circle expands, the square expands to maintain the condition of tangency.

find the rate at which the perimeter of the square is increasing.

find the rate of increase in the area enclosed between the circle and the square at the instant when the area of the circle is 25(pi) square inches.
Harley Weston lui répond.

Girth 1999-05-26
Carolyn Bulkley pose la question :
I am trying to explain to my son (who is in the 8th grade) how to figure girth. I'm afraid I have just confused him. Is there a simply formula to figure the girth of a box.

for example: I have a box that is 27" L X 22" W X 21" H.
Penny Nom lui répond.

Repeating decimals 1999-05-21
Stan pose la question :
Hi, I am in Honors Math, and have confronted everyone, including teachers, about repeating decimals. What interests me is the number 0.9... and 1. Everyone says that since there is no number between 0.9...(repeating) and 1, that 0.9... = 1. However, isn't a repeating number a representation of a number, and not a real number? Let's look at it this way. 0.9 is close to 1. 0.99 is closer. 0.99999999999999 is even closer. so, 0.9... is a representation of it's closeness to 1. it's an active number... I don't understand how 0.9... is equal to 1. Please help me prove that 0.9... does NOT = 1.
Penny Nom lui répond.
Introductory Algebra 1999-05-19
Pat pose la question :
(2 + sq. root of 3) x (2 - sq. root of 3) = 1

Please show me the work.
Harley Weston lui répond.

Three Daughters 1999-05-18
Norm Campbell pose la question :
I recently received a beat up copy of the three daughters question. I have only some of the question. It ends after the statement "the oldest one looks....... It does not finish. Is there any chance that someone can finish it off for me?
Rick Seaman and Harley Weston lui répond.
Circles, cirmcuference and area 1999-05-16
Stephen Ehrler pose la question :
I would appreciate if you could please tell me if what I discovered here is something or my ignorance? I noticed that a circle with r radii has the folling characteristic.

r = [2 * ( pi * r2 / pi * 2r)]

The equation states that the ratio of a circles area over its circumfrence = 1/2 that of the circles radii. It works every time. Did you know this ? Is it some kind of therom and can it be used for any thing? I thought this was intresting and would appreciate any input you may have.
Thank you.
Chris Fisher lui répond.

Square feet and acres. 1999-05-15
Helene Freeman pose la question :
How can I find out about acres in sq. ft. a house lot is 2360 sq. ft. and the house is on 1432 how many acres are left?
Penny Nom lui répond.
Re-Percentaging 1999-05-15
Doug Guion pose la question :
My mind has gone blank. I have a series of percentages which have been establised by the same base number. I need to remove one of the percentages (13%) leaving me with 87%. I need to arifically inflate the remaining percentages to total 100%. Any help would be appreciated.
Penny Nom lui répond.
Related rates 1999-05-13
Tammy pose la question :
The sides of a rectangle increase in such a way that dz/dt=1 and dx/dt=3*dy/dt. At the instant when x=4 and y=3, what is the value of dx/dt? (there is a picture of a rectangle with sides x and y, and they are connected by z, which cuts the rectangle in half)
Harley Weston lui répond.
Missing the boat 1999-05-11
Judith Moe pose la question :
Our daughter is in Grade 3 and seems stubbornly determined NOT to learn how to add and subtract. She's been assessed as quite intelligent in reading and writing,...Do you know of any alternative approaches to teaching/learning math that are proving useful in such circumstances.
Diane Hanson lui répond.
A log problem 1999-05-08
N. Lam pose la question :
I don't understand how to do this type of question:

log(base absolute value x)y = log(base abs.val.x)2 + log(base abs.val.x)(Cos x)

How do you graph the equation also, if -2(3.14)<=x<=2(3.14)
Harley Weston lui répond.

Base 2 to Base 10, conversion, convert 1999-05-08
Larry Bader pose la question :
101000112 is the same as what number in Base ten?

a. 83
b. 128
c. 93
d. 326
e. 163
Penny Nom lui répond.

Equivalence Relations 1999-05-06
Megan pose la question :
I am tutoring a boy who got this assignment from his teacher and I have no clue how to do it because I don't even know what the questions is asking! I need some help. Hereit is: "Give five examples of relations which are not equivalent relations and five examples of equivalent relations and explain why they are equivalent relations." This is seventh grade and I read about it in his book but it is not coming together for me.
Chris Fisher lui répond.
A Polar Plot 1999-05-06
Irene pose la question :
Consider the polar equation r=2-3Cos(theta/2) In the interval [o, 4Pi], how would you find the area of one of the leaves and also the length of one of the edges of a leaf?
Harley Weston lui répond.
48 cents with 6 coins 1999-05-05
Belinda pose la question :
i'm in 5th grade. my teacher asked this question: what are two ways you can make 48 cents out of 6 coins? i could only figure out one way. please help.
Chris Fisher lui répond.
Evens and odds 1999-05-04
Emily Hays pose la question :
My name is Emily Hays, I am in the 6th grade and my teacher gave me some extra probelms to see if I could solve them. She can't find the KEY and I can't figure out the probelm so she suggested I e-mail you guys to see if you could help us. Here's the Problem:

The numbers 1,2,3...,1999 are written on the blackboard in the classroom. Evertime the teacher enters the room he chooses two numbers on the blackboard, say a & b, with a> or equal to b, then he erases them and writes the difference a-b somewhere on the blackboard. After this procedure is carried on 1998 times, there will be only one number left on the blackboard. Prove the last remaining number must be even.

I hope you can help us!
Chris Fisher and Harley Weston lui répond.

The Jasper Project problem solving problem posting 1999-05-04
Heidi Laura Bergman pose la question :
I am a pre-service teacher in my third semester (out of four) of student teaching at the University of Wisconsin - Madison. I am wondering if you can tell me anything about "The Jasper Project" or where I might be able to find out more information regarding this topic. Thanks, Heidi
Rick Seaman lui répond.
Shape-preserving transformations 1999-05-04
J McAndrew pose la question :
A shape preserves its shape if a rotation, translation or scaling is performed on it. Are these the only continuous transformations which have this property? These transformations if performed on the parts and then summed have the same effect as the transformation being applied to the whole; are these linear transformations? Who, and what area of mathematics has classified all transformations of this type completely?
Chris Fisher lui répond.
Parabolic shapes 1999-05-04
Justin Ailor pose la question :
Can you give me some parabolic shapes?
Penny Nom lui répond.
A 1999-05-02
Leah pose la question :
a=b
a^2=ab
a^2+b^2=ab-b^2
(a-b)(a+b)=b(a-b)
a+b=b
b
2=1

why is this proof wrong?
Penny Nom lui répond.

A rhombicosidecahedron 1999-04-30
Himmat pose la question :
What is a rhombicosidecahedron?
Harley Weston lui répond.
Roman Numerals 1999-04-29
Michelle Jenkinson pose la question :
Someone proposed this question to me and I do not know the answer, so I was wondering if you could help. How, using Roman Numeral, did people add, subtract, multiply, and divide with no zero or negative numbers?
Penny Nom lui répond.
An equilateral triangle on a square 1999-04-26
Ed pose la question :
My Grade 8 class and I were discussing the solution to the following problem:

What is the area of the largest equilateral triangle that can be drawn on a 5 cm square.

We used 5 cm as the base of our triangle and then drew the other two legs of 5 cm each to make the equilateral triangle. We then drew an altitude from the upper vertex to the base of the triangle. Using the law of Pythagoras with side a of 2.5 and side c of 5 we calculated side b to be 4.3 cm (the altitude). Therefore the area of the triangle would be 5 x 4.3 divided by 2 or 10.75 square cm.

The answer key to this resource says I am wrong.

What do you think? Have we interpreted the question incorrectly?
Chris Fisher and Harley Weston lui répond.

A bike race 1999-04-23
Bill Gepford pose la question :
Bill was in a bike race and his friend kyle calculated that if he went 15mph that he would cross the noontime checkpoint one hour early but if he rode 10mph he would arrive one hour late.
How far away is the checkpoint?

Penny Nom lui répond.
Question about 3rd degree polynomials 1999-04-23
Patrick Bryan pose la question :
What is the general solution to the equation with the form:

a*x^3 + b*x^2 + c*x + d = 0

I have once seen a solution to this a few years ago, but I do not recall if it was a general solution. What I do know, is that you could simplify this equation to:

a*x'^3 + p*x' + q = 0...
Doug Farenick lui répond.

Parallel and perpendicular lines 1999-04-23
Crystal Pilling pose la question :
My name is Crystal Pilling and I am in 9th grade algebra. We are currently studying parallel and perpendicular lines. I am having trouble with this problem: 3/4x - 5y= 16, (5,-6) I have to find a line that is perpindicular to this line on a graph.
HELP ME PLEASE!!!!!

Penny Nom lui répond.
Bill and Sam at the Casino 1999-04-23
Rham Stewart pose la question :
Bill and Sam went off to bet at the casino. Each started with the same number of dollars. At the end of the first hour, Bill had won 20$ and sam had lost 20$. At the end of the second hour, BIll had lost two thirds of his money, and Sam had won the same amount that Bill had lost. At that point, sam had four times as much money as BIll. How much did each one start with?
Penny Nom lui répond.
Radius of an arc 1999-04-22
Rusty Riddleberger pose la question :
I need to find the equation for finding the radius of an arc; I know the length of the arc (i.e the distance of the line connecting the two ends of the arc) and the height; (i.e the rise of the arc at its apex,) I had the formula years ago but it has lost me; this would be invaluable for work in new homes i.e. where we need to build an "arch" with a rise of 21" between two columns 11 feet apart
Chris Fisher lui répond.
Shopping at Wegman's 1999-04-22
Stan pose la question :
Joanne, Steve, Pat, Alice, Joan, and Bill go to Wegman's at the same time. Joanne buys 2 gal of milk, 1 dozen oranges, 8 apples, and 2 lb. of ground beef, paying a total of $13.24. Steve buys 3 qts. of milk, 5 lbs. of ground beef, 10 lb. of potatoes, and 2 bags of mixed vegetables, paying a total of $16.95. Pat buys 3 gal. of milk, 2 dozen oranges, 1 dozen apples, 5 lb. of potatoes, and 5 bags of mixed vegetables, paying a total of $25.09.
....
Find the cost of: 1 qt. of milk, one orange, one apple one lb. of ground beef, one lb. of potatoes, and one bag of mixed vegetables.

Penny Nom lui répond.
A ladder problem 1999-04-22
Michael Blade pose la question :
There is a cube box 3feet x 3feet x 3ft resting against a vertical wall on level ground. Resting against the outside corner of the box is a ladder 10 feet tall, this ladder is of course resting on the ground but also against the outside corner of the box and rests on the wall.

The question- the ladder is divided into two unequal section bounded by the box to the ground and the box to the wall. what are those dimensions?
Penny Nom lui répond.

Area of a triangle from vertex coordinates 1999-04-21
Mark Tyler pose la question :
I'm no schoolkid, but I liked your answers about triangles. You might enjoy a quick look at this, the kids may too.

I was working on a Voronoi dual where I had to calculate the areas of very many triangles expressed as vertex coordinates, so I derived the following very direct formula:

A = abs((x1-x2)*(y1-y3)-(y1-y2)*(x1-x3)) for triangle (x1,y1)(x2,y2)(x3,y3)

I've never seen this in a textbook. Is it original? I doubt it, the proof is only a few lines long.

Regardless, it may be fun for the kids, even if it's not on the curriculum.
Walter Whitley lui répond.

Radius of convergence 1999-04-21
Nowl Stave pose la question :
Why is the radius of convergence of the first 6 terms of the power series expansion of x^(1/2) centered at 4 less than 6?
Harley Weston lui répond.
Circles 1999-04-21
Alex Elkins pose la question :
How do you find the circumference of a circle if you only know the radius and the square feet or inches of the circle if the radius is 18 inches, If done in inches do you multiply by 12 to get the square feet?
Jack Lesage and Harley Weston lui répond.
The average rate of change of a function 1999-04-20
Tammy pose la question :
Suppose that the average rate of change of a function f over the interval from x=3 to x=3+h is given by 5e^h-4cos(2h). what is f'(3)? I would appreciate any help with this question.
Harley Weston lui répond.
Unit conversions 1999-04-20
Deanna pose la question :
My question has to do with unit conversions with English and metric systems. I need to know how to use conversion factors with powers of 10. Which way do i move my decimal point. ex. .48kl to liters. Thank you.
Jack LeSage lui répond.
A Series 1999-04-20
Deepak Shrestha pose la question :
Given the sequence an=e^(-n*Ln(n)), does the series converge and why?
Harley Weston lui répond.
The halfway mark 1999-04-20
Sherry & Tom McGee pose la question :
How do you figure the halfway mark between 1/3 and 2/3 as a fraction and a decimal point?
Penny Nom lui répond.
The birthday problem 1999-04-19
Gordon Cooke pose la question :
How do I explain the rapid rise in the probability that at least two people in a group of n have the same birthday. We have derived the formula for p(n) and have graphed it and have seen how the results are counter-intuitive. At around n=23 p(n)=.5 and at n=50 p(n) is very close to 1. It does not help to simplify the problem (eg use months instead of days) because then our intuition does correspond more closely to reality. Is there some way we can see how the probabiltiy of a "collision" increases with n? It makes me think of data storage problems and hash tables in computer science.
Harley Weston lui répond.
Work jobs 1999-04-19
Cindy Miller pose la question :
Hi. I'm a college student, majoring in Elementary Education. This semester I am taking a math class for elementary school teachers.

I'm not sure if you can help out, but here is what I need. For the class, I am supposed to make 10 work jobs for students. Simple things that teach math that students can work on individually, for example after finishing a test.

If you have any suggestions, I would really appreciate it.
Penny Nom lui répond.

Volume of oil in a tank 1999-04-17
Lars Waldemarsson pose la question :
My problem is to get an equation for the depth of the oil in a gastank formed like a cylinder. The cylinder is in a horizontal position and by a stick you will be able to get the depth of the oil in the tank. All I need is an exmaple which I can build on. By this equation you will be able to get the volume of the oil if you know the depth.
Harley Weston lui répond.
Ounces and milliliters 1999-04-17
Tony Rizzi pose la question :
I'm mixing a formula of:

48 oz distilled water.
15 grams of Hydroxy Ethyl Cellulose GR (powder)
30 grams of Hydroxy Ethyl Cellulose MR (powder)
200 grams of Barium Sulfate (powder)
1000 grams of Calcium Hydroxide (powder)

After mixing, I need to estimate the amount of each ingredient that fits in a 3ml syringe. And how many syringes I can fill?
Harley weston lui répond.

y=mx+b 1999-04-15
Selena Royle pose la question :
When solving a problem on slopes,and in the formula y=mx+b what do the M and B stand for? Why M and B?
Penny Nom lui répond.
Extra point questions 1999-04-15
W Troy Council pose la question :
My teacher has given me 5 extra point questions. I have figured out two, but i need a little assistance with 3 others, could you help me with:
  1. A stablehand agreed to work for 1 year. At the end of that time, she was to receive $240 and one horse. After 7 months she quit the job, but still received the horse and $100. What was the value of the horse?

  2. If the roots of x2 + bx + c are pi and square root 2, then find "b" and "c."

  3. ...

Penny Nom lui répond.
The Binomial Theorem for rational exponents 1999-04-15
Angela Evans pose la question :
The full question is this: Isaac Newton generalized the Binomial Theorem to rational exponents. That is, he derived series of expansions for such expressions as (x+y)-3 (x+y)2/3 (x+y)5/6 What did Newton find? What are the first four terms of the series expansions of binomials above? How can this extended Binomial Thrm. be used to aid in calculations?
Penny Nom lui répond.
Two contest problems 1999-04-14
Bruce Baldwin pose la question :
We have students that are preparing for the Pythagoras Contest which is a nation wide Grade 6 math challenge.

In the preparatory tests we have run into several questions that we can not understand.

Is there anyone who can help us?

  1. If 1 * 9 = 0, 9 * 8 = 72, 2 * 8 = 9, then 9 * 9 = ?

  2. ...

Judi McDonald and Walter Whiteley lui répond.
Dividing a Circle 1999-04-12
Mike Kenedy pose la question :
I am having trouble with a homework question for bonus marks. A Circle is continually divided by lines that do not intersect the center so that they produce the most pieces of circle. For example
  • 1 line divides the circle into 2.
  • 2 into 4.
  • 3, however into 7.
  • 4 into11
  • 5 into 16
  • 6 into 22
  • 7 into 29
  • 8 into 37
  • etc...
I am stumped and cannot figure out the equation, though I'm sure it involves squares. Can you help?

Penny Nom lui répond.
Cross-sectional area of a cylinder 1999-04-12
Rebecca Connor pose la question :
What is the formula to find the cross-sectional area of a cylinder?
Chris Fisher lui répond.
Linear programming and optimization 1999-04-09
Shams pose la question :
What is Linear programming and optimization?
Jack LeSage and Penny Nom lui répond.
Grade 10 math 1999-04-08
Ron pose la question :
the type of question i'm having trouble with is 5(2x-1)=3(x-4)
Penny Nom lui répond.
Dotted graph paper 1999-04-08
Bridget Winward pose la question :
A teacher at our school is trying to locate dotted graph paper online or in print. His class would like to make three dimensional, geometerical drawings.
Please let us know if you have a good source.

Jack LeSage lui répond.
Converting Metric Measurements 1999-04-08
Rick pose la question :
Do you have any simple explanations for converting Metric measurements to other Metric measurements?? What helpful hints do you also have for a 5th Grader...
Penny Nom lui répond.
Universal Area 1999-04-08
Karen Richardson pose la question :
I need a formula for area that works for a square, a rectangle, a parallelogram, a trapezoid, and a triangle.
Jack LeSage, Chris Fisher and Harley Weston lui répond.
Instant Winner 1999-04-07
FSSTAN pose la question :
The probabilities of being an "instant winner" of $25 or $50 in a lottery are 1/600 and 1/1200, respectively. The mathematical expectation of being an "instant winner" of $25 or $50 is?
Jack LeSage and Penny Nom lui répond.
Area of an irregular shaped objects. 1999-04-07
Jesse Townsend pose la question :
How do I find the surface area of an irregulary shaped object such as someone's knee from the thigh to shin?

Thanks.
Walter Whiteley lui répond.

Large Numbers 1999-04-05
CK pose la question :
Hello. I need a lesson plan for grades 4 to 7 dealing with the concept of large numbers. Specifically, how to teach scientific notation. The lesson plan has to deal with the following: the size of the universe is so huge that is is almost beyond the ability of the mind to comprehend. One way is to measure...
Chris Fisher lui répond.
Volume of a cube. 1999-04-04
Alex Elkins pose la question :
How do you find the volume cubic matter of a cube or space, example how many cubic feet in an example 6" high 4' X 6' rectangle

Thank You
Penny Nom lui répond.

Pi/4 1999-04-04
Daniela Annarella pose la question :
What is the 30th digit of pi(1/4) after the decimal point?
Harley Weston lui répond.
T-shirts 1999-04-04
Valerie pose la question :
At a discount T-shirt shop the manager marked a special batch of T-shirts that originally sold for $2.00. When all the shirts sold the shop had collected $603.77.

How many shirts did they sell and what was the price per shirt?
Jack LeSage and Penny Nom lui répond.

Finding Excluded Values 1999-04-01
Lorraine Le Cam pose la question :
The question asks me to find the value of the variable that must be excluded in each rational expressionion. The operation is:

a
______
a - 2

How do I work this out?
Harley Weston lui répond.

Quadratic equations 1999-03-31
Ken Niebergall pose la question :
#1 a2 - 10a = 2a - 36

#2 t(t - 5) = 5 (t - 5)

#3. (x + 4)(x - 3) = 8

Thanks.
Jack LeSage and Penny Nom lui répond.

Factoring 1999-03-30
Maggie Stephens pose la question :
I don't know anything about factoring would you plese help me.

3x4 - 48

54x6 + 16y3

125-8x3

12x2 - 36x + 27

9 - 81x2

a3 + b3c3

I would greatly appreciate any help you can give me thanks.
Jack LeSage lui répond.

Standard Form 1999-03-30
Pam pose la question :
How do you put this equation into standard form?

y=3.572x+5.409

Would you please put this equation in this form Ax+Dy+C=0
Penny Nom lui répond.

A Frustum 1999-03-29
Monica Armour pose la question :
What do you call a square pyramid that has had the top chopped off?
Chris Fisher and Jack LeSage lui répond.
Factoring polynomials 1999-03-29
Karen pose la question :
I have been unable to factorise a polynomial equation and was wondering if you could please help. It is level (10-12) maths. The polynomial is x3 + x2 - 24x + 36
I have tried a few factorisation methods such as foctorisation by grouping but it won't work this polynomial. Please help.

Jeff Walters and Jack LeSage lui répond.
Resources for real-world math activities 1999-03-26
Kate O'Brien pose la question :
Where is there a collection of math acitivities or projects to use in high school Algebra I, Algebra II, or Trigonometry that tie concepts to real-world careers?
Jack LeSage lui répond.
Cubic feet and gallons 1999-03-26
Karen Coheley pose la question :
How many gallons in a cubic ft. ??
Harley Weston lui répond.
Complex numbers/polar coordinates 1999-03-25
Kate Cegelis pose la question :
What is the relationship between complex numbers and polar coordinates?
Harley Weston lui répond.
Prime dates 1999-03-25
Jessica Brown pose la question :
I'm asking how do you figure out all the prime numbers in a year and, whats the average amount of prime numbers per week.
Jack LeSage and Penny Nom lui répond.
A word problem 1999-03-25
Anna Gariss pose la question :
A second number is 4 less than a first number. The product of the second number and 3 more than the first number is 18. Find the pair of numbers.
Jack LeSage and Penny Nom lui répond.
Rhomboid 1999-03-25
Monica Armour pose la question :
I need to see a net of a rhomboid. Where can I find one on the net? Is it like a square paramid with the top chopped off? Help! This has me stumped.
Jack LeSage lui répond.
Probability and Statistics 1999-03-25
Karrie Waller pose la question :
Hi my name is Karrie and I am an elementary ed. student at Florida State University in Tallahassee, Florida. I am doing a report on how children learn probability and statistics. I am having trouble locating information that will tell me specifically how students learn. I am wondering if you can answer this question for me or direct me in the right direction.
Jack LeSage lui répond.
A field trip 1999-03-18
Jennifer Rudd pose la question :
This word problem is driving me nuts! I could really use your help. Its a secondary level question. Here it is:

A group of students planned to charter a bus for a school field trip. Each student was to share the $810 cost equally. However, 3 people were unable to go and this increased the share of each person by $3. How many went on the trip?

Thanks!
Jack LeSage and Penny Nom lui répond.

Percentages 1999-03-16
Beth Barton pose la question :
If I have two figures and want to know the difference between them, in Percentage, how do I proceed with a calculation?

Example: 67,800 - 56,000 = 11,800
What percentage does this difference represent?
Jack LeSage lui répond.

0/11 1999-03-09
Jacob pose la question :
What is the term applied to 0 divided by a number.

In calculating slope problem my answer was 0 divided by 11. I don't know what to do with this answer or how to interpret it.
Jack LeSage and Penny Nom lui répond.

Factoring 1999-03-08
L. Sivad pose la question :
Question:
m2+6m+9-n2

Penny Nom lui répond.
An airplane problem 1999-03-08
B.M.R. pose la question :
A plane left New York and headed East to its destination 3600 miles away across the Atlantic. On the way back its speed was boosted by a 50 mph tail wind and it arrived an hour early. What was its normal speed?
Jack LeSage lui répond.
Metric Conversion 1999-03-07
TDestra pose la question :
Please help to answer this question: Is a cubic centimeter equivalent to milligrams or milliliters, and how many? Also, is it a liquid measure?
Penny Nom lui répond.
Where three sequences meet. 1999-03-06
Ali pose la question :
My name is Ali and I am in the 5th grade.

I have a math question:

What is the least positive integer meeting each of the following conditions:

  • Dividing by 7 gives a remainder of 4
  • Dividing by 8 gives a remainder of 5
  • Dividing by 9 gives a remainder of 6
Help!

Denis Hanson lui répond.
Reversing the direction of an inequality. 1999-03-06
Mallory White pose la question :
If the Problem was -4a plus -5 is less than or equal to 14, why would you change the sign to greater than or equal to?
Jack LeSage and Harley Weston lui répond.
Enlarging a Rink 1999-03-06
Jennifer Rudd pose la question :
I've been having difficulty with this one question involving area. The level of the question is Grade 11/12. Here it is!
A rink is 40 m long by 20 m wide. There are plans to enlarge it by 700m2 by adding a strip at one end and a strip of the same width along one side. Find the width of the strip. (Let the width of the strip by x meters.)

Jack LeSage lui répond.
The square root of two is never supposed to end 1999-03-06
a wondering student pose la question :
i am algebra II and am in the 9th grade. today we were talking about rational and irrational numbers. When we were talking about square roots my friend and i were talking and we thought of something. if you have a square with sides of length one then the diagonal of the square is the square root of 2. Now the square root of two is never supposed to end. But the diagonal of the square ends so therefore doesn't the square root of 2 end. our math teacher did not really answer our question because it was not in the lesson plan and not to many people would see where we were coming from. the answer is really bugging me and i would like to have your input.
Jack LeSage and Penny Nom lui répond.
Quotients 1999-02-25
Brian Healey pose la question :
what is a quotient?
what is a divisor?
what is a divident?


Jack LeSage lui répond.

Converting mm's to inches 1999-02-22
Paul White pose la question :
It has been a long time since high school and I do not remember how to convert mm to inches. Could you please tell me what this would convert to in inches? 210 X 254 mm.
Chris Fisher lui répond.
Divisibility by 9 1999-02-21
Razzi pose la question :
I've been having a hard time trying to solve the following problem and I was wondering if you could help me.

For any positive integer a let S(a) be the sum of its digits. Prove that a is divisible by 9 if and only if there exist a positive integer b such that S(a)=S(b)=S(a+b).
Chris Fisher and Harley Weston lui répond.

Finding a rule for a sequence 1999-02-17
Lindsey Masters pose la question :
I'm doing a maths investigation and i have a sequence which goes:-

13,16,25,32,45,56,73.

Our teacher told us we have to find a rule by looking at the differences of the terms until we find a constant. The first differences are:-

3,9,7,13,11,17.

The differences of these are:- ......

Please could you tell me how to work it out so that I could work out the rules of similar sequences.
Penny Nom lui répond.

A palindrome 1999-02-16
panajoti pose la question :
Find the smallest number that must be added to 70808 so that the digits would read the same backward or forward.
Penny Nom lui répond.
Four Corners Maths Problem 1999-02-16
Helen Williams pose la question :
I am currently a student teacher in the UK and I have to write a 1000 word report on the following maths problem which I am completely stuck on! PLease HELP!! Choose and 3 by 3 section of the hundred square. Add the total of the four corners. How many different groups of four numbers can you find that add up to that number? eg,
123
111213
212223
Total of 4 corners add up to 48.

Adding 2, 13, 22, 11 also make 48 etc..

How many different groups of 4 numbers would add up to 48?

How would these results compare with thoses obtained from a 3 by 3 square in which the numbers are consective? eg,
123
456
789

PLEASE HELP AS I AM COMPLETELY STUCK? WHY DO ALL THESE DIFFERENT WAYS ADD UP TO THE SAME NUMBER??
Harley Weston lui répond.

Circumference and Area 1999-02-16
Natalie pose la question :
finding the circumference of a circle? formula
finding the area of a parallelogram? formula

Penny Nom lui répond.
The Board Problem 1999-02-15
Avery pose la question :
Mr. Avery has 3-foot boards and 4-foot boards. If he puts the 3-foot boards in a line, they have the same length as the 4-foot boards put in a line. Altogether he has between 16 and 25 boards. How many 3-foot boards does he have?
Jack LeSage and Penny Nom lui répond.
Magic Squares 1999-02-11
Katie Powell pose la question :
My name is Katie Powell. I'm in the 7th grade, taking Algebra. I live in Houston, Texas. My problem is this:

"Use the numbers 1-9 to fill in the boxes so that you get the same sum when you add vertically, horizontally or diagonally."

The boxes are formed like a tic-tac-toe -- with 9 boxes -- 3 rows and 3 columns.

Can you help?
Jack LeSage lui répond.

Dig digs in the garden 1999-02-11
Katherine Shaw pose la question :
A circular garden has an a radius of 8m. Dig, the dog, is tied up to a fence that runs round the outside of the garden. Dig was able to dig up all the garden, apart from an area of 64 square metres, which he couldn't reach. How long was his lead?
Chris Fisher and Harley Weston lui répond.
Satellite dishes 1999-02-10
Katherine Shaw pose la question :
I have read your information on 'Why are satellite dishes parabolic", and I know the reciever should be placed at the focus of the parabola. Could you test this with lights beams and a parabolic mirror, or would light beams behave differently. Thanks.
Jack LeSage and Harley Weston lui répond.
Non-Euclidean Geometry 1999-02-10
Robert Smith pose la question :
Is non-euclidean geometry necessary for the college bound student? I have students that are inerested in teaching math one day. My school is restricted to Euclidean Geometry.
Walter Whiteley and Jack LeSage lui répond.
Word problems 1999-02-09
Brian Rodriquez pose la question :
Please answer these problems with a formula. Also explain in English step by step how these problems should be solved. I know the answer I just don't know how the answer was achieved Thank you very much for trying to help
  1. A ski lift carries a skier up a slope at the rate of 120 feet per minute and he returns from the top to the bottom on a path parallel to the lift at an average rate of 2640 feet per minute. How long is the lift if the round trip traveling time is 20 minutes?
  2. An airplane on a search mission flies due east from an airport, turns and flies due west back to the airport. The plane cruises at 200 miles per hour when flying east, and 250 miles per hour when flying west. What is the farthest point from the airport the plane can reach if it can remain in the air for 9 hours?

Jack LeSage and Penny Nom lui répond.
Grade 4 curriculum 1999-02-09
John pose la question :
My daughter is in grade 4 and her math teacher has asked her to write out the number 1 to 10,000. She is currently at 4567 and is sick of it. When I complained that this was not a usefull exercise she said that the Ministry of Education curriculum requires this and gave a photocopy of the page. It states: "read and write whole number to 10,000 in standard, expanded, and written forms (eg., 9367=9000+300+60+7 = nine thousand three hundred sixty-seven). Has the teacher interpreted this the wrong way?

Thanks John
PS. Do you have a web address for Ontario Math and Science Teachers organization?
Jack LeSage lui répond.

Primary Mathematics 1999-02-08
Syairul pose la question :
Mr Wu earned $2365 in January. He earned $375 more in February than in January. If he spend $4250 in the two months and saved the rest, how much did he save?
Jack LeSage lui répond.
John Napier and e 1999-02-06
Shimin pose la question :
I would like to ask about the exact definition of e, its history (like how John Napier came about discovering it) and its applications in problems and real life situations. Thank you!
Chris Fisher lui répond.
Dividing Decimals 1999-02-06
Melanie Campbell pose la question :
i ugently need to know how to divide a decimal by a decimal eg:6.0 divided by 2.4 i need to show all working on a basic skills exam please help!!!!

mel
Jack LeSage lui répond.

Lunes 1999-02-04
Kai G. Gauer pose la question :
A prof once told me that a certain type of lune is quadrable given that the diameter is an integer. She used the construction of a right isosceles triangle within a semicircle and later constructed another semicircle on the base of the first semicircle and used area subtraction to show equality to a smaller triangle with quadrable area. What happens when the original inscribed triangle is no longer isosceles? She mentioned something about other lunes also being quadrable; but not all. What are the dimensions of other such lunes? Note: I'm not certain if I still have my hercules account; please simply post on Q&Q.
Thanks!

Chris Fisher lui répond.
Modular Arithmetic 1999-02-04
Leslie Kupper pose la question :
I am trying to do a project on modular arithmetic. I was wondering if there were any websites that include a sample lesson plan on modular arithmetic for any grade level. Let me know where and how to find them. Thanks.
Harley Weston lui répond.
Money and Counting 1999-02-03
Deborah Goodman pose la question :
I am looking for ways to tutor my daughter in money counting and handwriting skills.
Jack LeSage lui répond.
Cannonballs 1999-01-27
Roger King pose la question :
How many cannonballs can be stacked in a triangular pyramid?
Penny Nom lui répond.
Simplifying Radicals 1999-01-26
Mary pose la question :
I would like to know how to simplify this question:
   
4 __________________ squareroot7 + squareroot3 
I know the answer is (sqrt7 - sqrt3) but i would really love to know how to get that answer!! Thanks.

Jack LeSage and Penny Nom lui répond.
Simplifying Radicals 1999-01-25
Randy pose la question :
Find the perimeter of a rectangle in simplified radical form L=root80 W=root45. I would appreciate a detailed explination of the process for solving.
Jack LeSage and Penny Nom lui répond.
The Quadratic Formula 1999-01-22
Eric Morgan pose la question :
Hi my name is Eric Morgan and I m in 8th Grade honors math (middle) and I'd like to know how to prove the quadratic formula -b±sqrt of b(a)(c)over 2(a)
Penny Nom lui répond.
Angles in Polygons 1999-01-21
Jen pose la question :
  • How do u find the interior angles of a pentagon when you are given 4 of the angles and you need to find the fifth?

  • If you are given the measure of each exterior angle of a regular polygon, how do you figure out how many sides the polygon has?

  • i need all information on polygons and how to find their angles!!!

Jack LeSage lui répond.
Root 17 is Irrational 1999-01-21
John Murdock pose la question :
If you could help me out with this I would appreciate it. Prove that the square root of 17 is irrational.
Harley Weston lui répond.
Math and Writing 1999-01-21
Nancy Waite pose la question :
This may not be an inquiry for this particular service, but we are searching for teacher resources incorporating writing into mathematics. With the new state math frameworks, our district is emphasizing using the writing process to develop thinking skills in math. We are gathering available resources in this area so we can begin formulating a plan to incorporate writing skills into the mathematics curriculum.
Walter Whiteley and Rick Seaman lui répond.
Math Olympics 1999-01-19
Kim Brandson pose la question :
I am trying to put on a Math Olympics for K-5 students in my district. Any ideas? Resources? Suggestions?
Jack LeSage lui répond.
Fitting a Curve 1999-01-19
Kirk pose la question :
Hello my name is Kirk from Scarborough, Ontario.

I have been out of a formal education system for thirty years. I program microcontrollers in my spare time. I have built a temperature sensing device ready to go but, thermistors are very non-linear. I do know that there is a way to calculate the input condition of the thermistor and display the correct temperature in degrees C. I am sending a file to show my progression so far.
Harley Weston lui répond.

Graphing the Derivative 1999-01-18
Milena Ghebre pose la question :
This question has been nagging me for sometime now.

Is there a way of finding out the derivative of a function, just by looking at the graph of it?
Walter Whiteley lui répond.

Calculus 1999-01-16
Kaylea Rankin pose la question :
Differentiate the following.

y = 1 /(2+3/x)
Jack LeSage and Penny Nom lui répond.

Linear Equations 1999-01-16
Casie Tomney pose la question :
My dad and I have been trying to figure, how to solve for x on any of these problems my teacher gives us. The problem is:

2h/3 + 1/2 = 5h/6 - 3/4

Thanks!!!!!!!!
Jack LeSage lui répond.

Turning Fractions into Decimals 1999-01-16
Lynn pose la question :
How do you do it step by step
Jack LeSage lui répond.
Levers 1999-01-13
Lane Campbell pose la question :
1. Solve for x or y.

(a)

<-----4m------><------4m-----><---------xm ---------> 
_____________________________________________________
^             ^               ^                     ^
25N          5N               ^                    15N 

Jack LeSage lui répond.
Patterns 1999-01-07
Melis Kalay pose la question :
I'm confused about questions like these:

1. 2by2by2 cube:

If this cube was painted blue on the outside,

  • how many cubes would have 3 blue faces
  • 2 blue faces
  • 1 blue face
  • 0 blue faces

Jack LeSage and Penny Nom lui répond.
Absolute value of i 1999-01-06
Wayne Bagley pose la question :
I would like to know what is the absolute value of i. I need an answer suitable for the secondary level.
Harley Weston lui répond.
Place Value 1999-01-05
Reg pose la question :
I work in a Section 27 classroom with various grades. I am looking for assistance on how to deliver a lesson on place value:decimal numbers keeping in mind that they need to see it (visual) to comprehend. I am looking for grade 4-6 level.
Jack LeSage lui répond.
A handshake problem 1999-01-05
Nick Lam pose la question :
There are 40 people at a party. 1 host couple, a mom and her daughter. There are 19 other guest couples, composed of moms and their daughters. The Host couple shakes hands with everyone except each other. Each guest mom shakes hands with everyone but their own daughter. Each guest daughter shakes hands with everyone except their own mom. A hand shake between two people is considered to be one handshake. HOW MANY HANDSHAKES ARE THERE?
Penny Nom lui répond.
Pythagorean theorem research project 1998-12-31
Mohammed Hasan pose la question :
Hi my name is Mohammed Hasan. I am a math honors student in 8th grade. I have to do a research project in math. The only problem is that I have to do the research project at a 10th grade level. I am having trouble raising the project at a tenth grade level. Would you please kindly take your time to give me some tips and web sites that will help me raise the Pythagorean theorem to a 10th grade level.
Jack LeSage and Walter Whiteley lui répond.
Geometry patterns lesson plans 1998-12-31
Vicki pose la question :
hi,,, my name is Vicki and I am a new 5th grade teacher....

Anyway, I'm supposed to come up with a lesson plan to

  • Explore patterns that result from cominations of "reflections, rotations, and translations of geometric figures.
The plan is to include:
  • writing/metacognition, assessment strategies, interdisciplanary connections, supplemental materials, or textbook, and Bloom's taxonomy level.
Any help you could give would be greatly appreciated.

Thanks
Jack LeSage lui répond.

The area of a triangle 1998-12-26
Elysia pose la question :
How do you figure the square inches of a triangle?
Harley Weston lui répond.
Complex numbers and the quadratic formula 1998-12-25
Richard Peter pose la question :
My age is 16, and my name is Richard. My question relates to the topic complex numbers & the quadratic formula.

I would like to know how to solve quadratic equations in which the discriminant is less than 0 (i.e. we get two complex solutions to the quadratic)

3x2+2x+5 = 0

and how mathematicians like euler contributed to this field. If it would be possible I would also like to know how this type of quadratic equations can be graphed?
Harley Weston lui répond.

Complex Numbers 1998-12-23
Wayne Bagley pose la question :
I would like to know what is the square root of i , and i squared? I am looking for a response appropriate for secondary level students.
Harley Weston lui répond.
Some Word Problems 1998-12-17
Jennifer Rudd pose la question :
To Whom It May Concern,
I'm having some difficulty with these word problems. Maybe you could help. Thanks.
  1. A matte of uniform width is placed around a painting so that the area of the matted surface is twice the area of the painting. If the outside dimensions of the matte are 40cm and 60cm, find the width of the matte.

  2. The Joneses start out A 1520km car trip to Walker Park. On the first day they cover 960km. On the second day they complete the trip, but a rainstorm causes them reduce their average speed by 10km/h.If the 2-day trip took a total of 20 h, what was the average speed on each day?

  3. Granny stood up at her grandson's wedding reception and announced " My age now is a perfect square and it is equal to the difference between the square of my grandson's father's age and the square of his mother's age. Come to think of it the difference my age and the square of my grandson's age is seven times the age of his mother, my daughter in law." The grandson's wife remarked to her new husband," That means the difference between the squares of our ages is three times the age of your father!" How old was the bride?

  4. The volume of a retangular box 4cm high is 144 cubic cm. If the perimeter of the base is 24cm, find the dimensions of the box.
P.S. the first two questions are the most important ones that need to be solved.

Thanks for your help!!
Jack LeSage and Penny Nom lui répond.

Indeterminate forms 1998-12-11
R. Dixon pose la question :
What is the correct evaluation of infinity/0 ? I've checked three different math sites. One says definitively, that infinity/0 is "not" possible. Another states that infinity/0 is one of the indeterminate forms having a large range of different values. The last reasons that infinity/0 "is" equal to infinity.
Walter Whiteley and Harley Weston lui répond.
Volume in gallons 1998-12-09
Hill Hermit pose la question :
Please tell me the formula for computing the volume, in gallons, of a cylinder. Thanks from a parent. American gallons, please.
Harley Weston lui répond.
6.99999... = ? 1998-12-05
Tom pose la question :
I have had a rather heated arguement with my students. Please settle this for me.

Solve <,>, =
6.99999... __ 7

Thank you.
Penny Nom lui répond.

Intersection of Planes 1998-12-03
Lindsay Fear pose la question :
My name is Lindsay Fear. I am an OAC student (which is the Ontario equivalent to Grade 12 in most other states and provinces). I am in an Algebra and Geometry course and am currently studying a unit on equations of planes. Our teacher has given us this question that my friend and I have attempted several times, but we are still unable to solve it. My teacher has also suggested using the internet as a resource. The question is:

Prove that a necessary condition that the three planes

 -x + ay + bz = 0 ax -  y + cz = 0 bx + cy -  z = 0 
have a line in common is that
a^2 + b^2 + c^2 + 2abc = 1

Walter Whiteley lui répond.
-(4)^0 = ? 1998-12-02
Derek Yau pose la question :
I would like to know why any number to the exponent 0 equals to 1 also, I would like you to please answer this question: -(4)^0 = ? I know the answer is 1 but I am confused as to if it is a negative one or a positive one.
Jack LeSage and Penny Nom lui répond.
Platonic Solids Surface Area 1998-12-02
Rachel Bidwell pose la question :
How do you find the surface area of the 5 platonic solids, when they each have a volume of one cubic inch
Harley Weston lui répond.
Percentage markup 1998-11-28
John Coffey pose la question :
My 11th grade daughter asked me how to calculate retail mark up percentages, I would appreciate any help with this question.
Penny Nom lui répond.
Pick any odd number, square it, and then divide it by 8 1998-11-27
Brenda Meagher pose la question :
Pick any odd number, square it, and then divide it by 8. No matter what odd number is chosen and squared and divided by 8, the remainder is one.

Could you please explain this to me or is there a pattern that I am not aware
Harley Weston lui répond.

Matricies 1998-11-26
Stephanie Webster pose la question :
If a matrix for a rectangle looks this way:
    AACC    BDDB 
What does the matrix for a square look like?

Penny Nom lui répond.
Duplation method of multiplication 1998-11-26
Sara Whitford pose la question :
I am wondering why 16 and multiples of 16 do not work in the ancient duplation method of multiplication used by the Egyptians. I discovered the method in the Journeys math text gr 7 level. Just curious. Am I doing something wrong??
Jack LeSage and Harley Weston lui répond.
Three keys 1998-11-26
Karen Chan pose la question :
A man has a bunch of three keys, only one of which fits the lock of his front door.
When he comes home in the dark he tries the keys at random until he finds the one fits. Find the probability that in a week of five nights, he tries the right key first on at least one night.

Penny Nom lui répond.
Algebra 1998-11-25
Casey pose la question :
yeah my son brought home a math worksheet and he was wondering and me too if u could help him and me out . he has problems like this 4n+9=7n+2= ??? and he has to show work so if u could help us out that would be great
Jack LeSage lui répond.
A number between 1998-11-25
Jimmy Nikola pose la question :
A number is less than 3,425 + 8,630 and greater than 7,614 + 4,429. What could the number be?
This question is on page 93, question number 23. in Silver Burdett Ginn Math book, which is a 3rd grade math book.

Jack LeSage lui répond.
The bricklayers formula 1998-11-24
Rachel Kaplan pose la question :
I have to do a report on the bricklayers formula N = 7LH. Can you give me any information on this.
Harley Weston lui répond.
Intersection of planes 1998-11-22
Dave Rasmussen pose la question :
I am a teacher of secondary mathematics with a question about the uses of Three Dimensional Co-ordinate Geometry. I have been teaching my students to write equations of planes and lines, - to find the intersection of these and the distance between them. What I am having difficulty finding are good applications of these techniques to "real world" situations. Can anybody help me?
Walter Whiteley and Harley Weston lui répond.
Fraction division 1998-11-18
Brett Darrough pose la question :
I am needing specific examples that illustrate division of fractions with In-depth understanding. I am enrolled in a CGI (cognitivly guided instruction) course which is trying to develop a method of teaching fraction division with understanding. Most people invert and multiply to obtain a correct answer. Why? I would like help in understanding this method that includes pictures and algorithms that illustrate reasoning and depend on understanding.
Jack LeSage and Harley Weston lui répond.
A tetrahedron inscribed in a cube 1998-11-18
Jane pose la question :
In analyzing a cube, I would like to find a tetrahedron inscribed in the cube which has none of its faces in the planes of the faces of the cube. I would like to see this tetrahedron outlined in the cube.

My name is Jane and my e-mail address is BARSOIAN. I am an elementary education student.
Walter Whiteley lui répond.

Three dice 1998-11-17
Ryan Allinson pose la question :
Rolling three regular dice how many different ways could a sum of 10 be rolled?

Hope you can help. Can you please show me how this is done?
Penny Nom lui répond.

Linear systems of equations 1998-11-16
Crystal Girvan pose la question :
My name is Crystal Girvan.Im in grade 11. I have a question.We are solving linear systems of equations: comparison method. My questions is. it says

a)use the method of comparison to solve this system a=b-1, 3a+ b=3

b) verify your solutin in a

I dont understand it. please help
Jack LeSage lui répond.

Terminating decimals 1998-11-16
Debra Karr pose la question :
A college student studying elementary education asked me a question that I could not think of the correct answer. How can you look at a fraction and tell if is a terminating or non terminating decimal?
Jack LeSage and Penny Nom lui répond.
A trig limit 1998-11-14
Amy Atwell pose la question :
what is the limit of of tanx / x + sin x as x approaches 0
Harley Weston lui répond.
Golf Problem - The Sequel 1998-11-13
Bob pose la question :
Sixteen golfers, seven rounds. What are optimum combinations for each golfer to play with as many different golfers as possible?

Many thanks,
Bob Payson
Denis Hanson lui répond.

What's the next term? 1998-11-12
Ilia pose la question :
What the formula and explonation for formula for next patterns:

1) 1, 4, 10, 20, 35, 56, 84,...

2) 0, 6, 30, 90, 210, 420,...

Thanks!
Penny Nom lui répond.

Arithmetic Progressions 1998-11-12
Gerry Boser pose la question :
It has been years since I was in school and I can't remember if there is a formula for the following problem:

If you deposit $1.00 on the first day of the month, $2.00 on the second day, $3.00 on the third day . . $31.00 on the last day of the month, how much do you have in the bank?

Now will this formula also work if it was, $0.25 (then day two you would deposit 2x $0.25 or $0.50, day three you would deposit 3x $0.25, $0.75. . . ). Will it work with any denomination??

Thank you for your time. I promise I'll write this one down for future reference. . .
Penny Nom lui répond.

Two sides and a bisectrix. 1998-11-11
Victor Grinshtein pose la question :
I am looking for someone who can tell me how to construct a triangle by 2 sides and a bisectrix using a compass and a ruler.
Chris Fisher lui répond.
Centimetres 1998-11-11
Vicky Caldwell pose la question :
I work in Carpet Manufacturing and I need to know how to figure the calculation for a roll of carpet in centimeters. For example: a 12 x 100 roll of carpet equals 133.34 square yards, which is 100 linear ft. and 1,200 square foot. Can you please tell me how I would figure to get CENTIMETERS???????
Jack LeSage lui répond.
Touch Math 1998-11-09
Melinda Robinson pose la question :
I am a contracted district substitute teacher for grades K-8. My teacher education courses did not include anything about "touch math," a system used by some of the teachers for whom I sub. Is there a book available that I could acquire to teach this system to myself, and have as a reference?
Harley Weston lui répond.
Kumon 1998-11-09
Kathy Steele pose la question :
Perhaps I am not spelling this correctly,since there is nothing to be found on Kumin Math, but my search for info on this topic led to this site. My understanding is that it is a program of repeated drills. Do you have any additional information? I know that this will come up during Parent conferences since some of my Jr. High students are talking about it.
Jack LeSage and Harley Weston lui répond.
Triangular Numbers 1998-10-30
Matt pose la question :
i would like to know about triangular numbers and it history i would also like to know about the history of prime numbers thank you
Chris Fisher lui répond.
Divisibility by 11 1998-10-28
Pat Duggleby pose la question :
I am an upgrading instructor at a drop-in program in Regina. One of my students is taking General Math 30 through correspondence, and we have run into some confusing instructions. The section is about divisibility rules, and we did just fine up until the rule for Divisibility by 11. The statement is as follows:
If the difference between the sum of the odd-numbered digits and the sum of the even-numbered digits, counted from right to left, is divisible by 11, then the number is divisible by 11.
.
.
.

Penny Nom lui répond.
A Puzzle 1998-10-27
Bruce Bragnu pose la question :
We are trying to solve what SHOULD BE a simple 7th grade problem and have run into a wall.
It is:
ABCD
ABCD
ABCD
ABCD
-------
EBEA

It is an addition problem. Each particular letter represents the same digit. We are looking for what number "B" represents. We have tried a multitude of solutions and have come up empty.
Penny Nom lui répond.

Fractions 1998-10-27
Jessica Braimoh pose la question :
I have a problem that I just can't figure out!!

Put into a fraction a) -1.157... b) 0.046... c) 0.032... d) -0.3234... Please show how you got the answer and how you came to it(step by step)
Thanks Jessica Braimoh grade 9 Ontario
Harley Weston lui répond.

A Six Digit Number 1998-10-27
Craig Bedard pose la question :
If a certain six-digit number is split into two parts, one constituting the first three digits and the other the last three digits, and the two parts are added and the resultiong sum squared, it is found that the product is the original six digit number. What is the original six-digit number?

At first it seemed liked an impossible question, until it hit me...how long will it take you?
Jason Stein and Dan Usselman lui répond.

A Number Trick 1998-10-26
Brenda Meagher pose la question :
I'm a 37 year old mother and i have returned to school for personal reasons. I was faced with this question.
Choose any number less than 10, multiply it by 8547, then take your answer and multiply it by 13. I chose the number 8.

8547
x 8
--------
68376

and

68376
x 13
---------
205128
68376
---------
888888

Any number chosen from 1 to 9 will result in the same form of answer.If the number two is used you will end up with 222,222.etc So my question is, is there another number that will results in the answers.
Harley Weston lui répond.

Logs 1998-10-21
Benny pose la question :
What does log means? How come we have to use log
Chris Fisher lui répond.
Complementary and Supplementary Angles 1998-10-21
Christina Saunders pose la question :
I am in 9th grade and my math teacher wanted us to find out why complimentary angles are called complimentary and why supplimentary angles are called supplimentary. I have looked everywhere and asked numerous people, but I have yet to find an answer. My math teacher said it had something to do with trigonometry. Do you have an answer for me?
Chris Fisher and Penny Nom lui répond.
The Left Side of a Parabola. 1998-10-20
Shay pose la question :
Find the parametrized equation for the left half of the parabola with the equation: Y=x^2-4x+3
Chris Fisher lui répond.
Adding Fractions 1998-10-15
Lindsay pose la question :
please help me!!!!
Harley Weston lui répond.
Problem Solving 1998-10-15
Pamela Fisher pose la question :
Can you give me a comprehensive list of problem solving stategies. I teach grade one in a K to 8 school and we are working on improving problem solving at all grade levels. I have heard that there is a list of various strategies that we could adapt to different grade levels. Any help you give me would be appreciated.
Thank you. Pamela Fisher

Walter Whiteley lui répond.
A Linear System 1998-10-08
Jason Bussey pose la question :
The linear systems with the following pattern all have the same solution. Is their some kind of reasoning as to why this is so?

2x+3y=4
3x+4y=5

4x+5y=6
5x+6y=7

The solution is always x=-1, y=2

Thank you
Jason
Penny Nom lui répond.

Operations Research 1998-10-08
Lisa Barrett pose la question :
What is the history of operations research and the study of linear programming?
Judi McDonald lui répond.
Fractions 1998-10-07
Nikki Lakevold pose la question :
-5 over 9 minus -2 over 3 plus -7 over 6 = ???

This is a fraction question and I really don't know why the back of my textbook says -19 over 18 when I got -23 over 18,, am I wrong???
Harley Weston lui répond.

Composite Numbers 1998-10-07
Greg Murphy pose la question :
What type of composite number has an odd number of factors?
Harley Weston lui répond.
Scientific Notation 1998-10-07
R. Pierce pose la question :
Help! How do you express the following numbers in scientific(exponential)notation:0.00036 and 2998000000. I understand how to solve them if it was an equation, but this is confusing me. Please help me answer my questions. Thank you.
Harley Weston lui répond.
A Kite 1998-10-07
Paul Scott pose la question :
What is the mathematical term for the kite shape?
Walter Whiteley lui répond.
Number Systems 1998-10-07
Frans pose la question :
What other number system are there besides the real number system and the complex number system?
Interested adult
thanks

Penny Nom lui répond.
A Sum or Product of Fractions 1998-10-06
Emily Robb pose la question :
Find a pair of fractions that when they are multiplyed and added the sum /product is the same
Penny Nom lui répond.
Points on a Graph 1998-10-03
Nouver Cheung pose la question :
If the point P(-3,2) is on the graph of y=f(2x-1), what point must be on y=f(x)-3?
Harley Weston lui répond.
Adding Fractions 1998-10-03
Pam Bailey pose la question :
Can you help me simplfy this?

(1/2a + 1/3b) - (1/4a - 1/5b) + (1/6a - 1/7)

thanx
Harley Weston lui répond.

Students and Lockers 1998-10-02
Mike pose la question :
There is a row of 1000 lockers.
There is a line of 1000 students.

Student number 1 starts at the first locker and opens all 1000. Student number 2 starts at the second locker and closes every other one. Student number 3 starts at the third locker and goes to every third one, closing the open ones and opening the closed ones. Student number 4 does the same with every fourth locker and so on down the line... After all 1000 students have gone how many lockers are open and which ones are they?

Please help! There is proboly a simple solution but we couldnt figure it out for the life of us. Please let us know how you solve it.
Patrick Maidorn and Penny Nom lui répond.

French Francs 1998-10-01
Richie Franklin pose la question :
1.what did one dollar equal in France francs ten years ago, twenty years ago, and fifty years ago?
Chris Fisher lui répond.
Dividing a Class 1998-10-01
Tom Barker pose la question :
My eighth grade niece called with the following homework problem:

A teacher wanted to divide her class into equally numbered groups. She tried to divide the class into groups of two, but was one student short. She tried to divide the class into groups of five, but was one student short. She tried to divide the class into groups of seven and was successful. What is the least number of students that were in her class?

I know the answer is 49, but don't know how to prove it. I must be getting old if I can't solve eighth grade math problems. Your assistance would be appreciated.
Penny Nom lui répond.

Repeating Decimals 1998-10-01
Chris Norton pose la question :
Could you PLEASE give the formula to find out the number of digits in a repeating decimal before it repeats. I have been trying to get it for weeks from Math sites on the Internet. Can you please, please help me ?
Chris Norton

Chris Fisher and Penny Nom lui répond.
Two Chords 1998-09-29
Jennifer Cane pose la question :
Question:
two parallel chords of a circle, AB and CD, have lengths of 10 cm and 17 cm respectively. The diameter of the circle is 21 cm. Find the shortest distance between the chords.

Harley Weston lui répond.
An Implication 1998-09-27
Danielle Evans pose la question :
i am in my second year of math for the liberal arts and a problem has be terribly confused..

can you answer this

[(p --> q) ^ (q --> p)] --> (p <--> q)

is this an implication??

i would love to hear your answer

thank you...

danielle evans
Chris Fisher lui répond.

A Horizontal Line 1998-09-23
Tess Warer pose la question :
Find the equations of a line through (-1,-5) and parallel to the X-axis.
Harley Weston lui répond.
Nickles on the Highway 1998-09-22
Ronnie Mac Donald pose la question :
How many nickels would it take to cover 226km of highway,each nickel is 2cm in diameter?
Penny Nom lui répond.
A Hexagon 1998-09-22
Lee Curtis pose la question :
Could someone calculate this for me?
If a hexagon is 38 feet 8 inches across, how wide would each of the six sides be?

Thank you,
Lee Curtis
Chris Fisher and Harley Weston lui répond.

Help the Helper 1998-09-20
John Derr pose la question :
I am TRYING to help my niece with her Community College Teacher's math course! I have a BS and an Engineer yet stumble on what her book is asking:

  1. Fill in the blanks to continue this sequence of equations:
    1=0+1
    1+3+1=1+4
    1+3+5+3+1=4+9
    _______________=____
    _______________=____
  2. What expression, suggested by part (1.), should be placed in the blank to complete this equation?

    1 + 3 + 5.........+ (2n-3) + (2n-1)+ (2n-3)+...+5 + 3+ 1=_________


Penny Nom lui répond.
Five Factors 1998-09-19
Derek Yau pose la question :
To whom it may concern,

I have difficulty in getting the solution to the following question:

Find 5 numbers that have exactly 5 factors.

I got 16, 81 but couldn't find the rest. I believe that in order to have 5 factors, it has to be a square number. Isn't it true? I guess there may be a pattern to this.

Thanks for your help.
Derek Yau.
Penny Nom lui répond.

Rational and Irrational Numbers 1998-09-19
Ri pose la question :
I am trying to explain rational & irrational numbers to my niece who is grade 7 and am having difficulties. Could you please explain the difference between rational & irrational numbers.

Thank you
Ri
Penny Nom lui répond.

Simplifying Roots 1998-09-18
Lauren Lattimer pose la question :
1. 2root27 divided by root 12

2. 3 root 48-root 75
Penny Nom lui répond.

Probability 1998-09-17
Chris pose la question :
Six marbles are placed in one of three boxes. What is the probability that each box contains two marbles? What is the formula used?
Penny Nom and Chris Fisher lui répond.
Unit Fractions 1998-09-16
Murray MacNeil pose la question :
Sir, my nephew is having trouble with math,he is in grade 10. this is his question.

Find seven unit fractions whose whole sum is one.

thank you
murray macneil
Penny Nom lui répond.

Random 1998-09-15
Hugh Ballantyne pose la question :
I am an occasional teacher.
Here is my question:
Does the word "random" have a technical meaning in mathematics?

Harley Weston lui répond.
Radicals 1998-09-15
Lana Sabo pose la question :
Question:
fifteen times the square root of twenty, divided by the square root of 2.

nine subtract the square root of forty-five, divided by 3.

the square root of 18 plus the square root of 12, divided by the square root of 3.
Harley Weston lui répond.

A Pattern 1998-09-14
Krystin pose la question :
Question:
1=1x1
1+2+1=2x2
1+2+3+2+1=3x3

draw a series of diagrams to illustrate the above pattern
Penny Nom lui répond.

Human Calculator 1998-09-14
Pam Sloan pose la question :
I recently saw a special on NBC Dateline about a man known as the human calculator. They called him Mr. Math. I want to know more about his books, seminars, and activities. Also, what is his real name?
Patrick Maidorn lui répond.
(1+z+z^2)^2 1998-09-10
A.R. pose la question :
These questions deal with factoring.

(1+z+z^2)^2 and (p^2-pq+q^2)^2

I partially understand the second line which would be 1+z^2+z^4+2z+2z^2+2z^3 but I don't understand where the 2 comes from in the second half of that line.

p.s.(^2 means squared or cubed etc.)

Please help me out A.S.A.P.!
I have a quiz on this tomorrow!
Thank-you,
A.R.
Harley Weston lui répond.

Triminoes 1998-09-09
Roxanne Hale pose la question :
I am doing an investigation about a game called triminoes (like dominoes). The game is played using triangular pieces of card. Each card has 3 numbers on it. I have to investigate the relationship between the number of trimino cards in a set and the largest number on the cards. I found;

largest no. used 0 1 2 3 4
no. of trimino cards 1 4 10 20 35

I was ginen the formula for this which is:
UN= UN - 1 + 1/2 (n + 1 ) (n+2)

UN=no. of trimino cards n= largest no.

I don't know how to get to this equation I think it has something to do with triangle numbers!
Penny Nom lui répond.

Cutting a Pizza 1998-09-09
Woody pose la question :
what is the greatest number of pieces of pizza you can form if you use five straight cuts to cut the pizza? answer given is 16. please draw a diagram of the answer.
thanks, woody

Penny Nom lui répond.
3 to the power of 1994 1998-09-05
Kim Tangney pose la question :
What are the last two digits of:
  1. 3 to the power of 1994

  2. 7 to the power of 1994

  3. 3 to the power of 1994 + 7 to the power of 1994

  4. 7 to the power of 1994 - 3 to the power of 1994

Penny Nom lui répond.
A divisor. 1998-09-05
Kim Tangney pose la question :
When 391 758 and 394 915 are divided by a certain three digit numbers, the three digit remainder is the same in each case. Find the divisor.
Penny Nom lui répond.
Rational Numbers 1998-09-05
Kristin Mckenzie pose la question :
Iam a secondary student with a math question I don't know how to do.
This is the question:

Explain whether each decimal number represents a rational number.

(a) 0.16

(b) 0.12

(c) -3.125

(d) -0.27

(e) -0,212 112 111 2 ....

(f) 0. 457 92

If it wouldn't be a problem i would really appreciate it if you sent back the instructions on how to do the question.

My name is Kristin Mckenzie and my return e-mail is lexus1999@hotmail.com

Thank-you for you time
Jack LeSage and Harley Weston lui répond.

Volumes 1998-08-29
Lorraine Wall pose la question :
Consider the region in the first quadrant bounded by the x and y axes, the vertical line x=3 and the curve y = 1 / (x squared + 3). Determine the volume of the solid by rotating this region about the x-axis. Now that is the first part.
I then have to find the coordinates of the centroid of the solid by rotating this region about the x-axis.

Thanks.
Lorraine
Harley Weston lui répond.

The area and the circumference of a circle. 1998-08-27
Jason Wright pose la question :
I was looking at the relationship of the area of a circle and the circumference when I realized that 2*pi*r is the derivative of pi*r^2. I was wondering if there is any connective deep dark meaning as to why this appears to be related. Thanks for any help you can give me!
Walter Whiteley lui répond.
Golf problem 1998-08-25
Bob pose la question :
Twelve golfers plan to play seven rounds of golf. Each would like to play as many rounds with different golfers as possible. What are the optimum combinations to accomplish that goal?
Denis Hanson lui répond.
Frieze Patterns 1998-08-19
Brian Bairstow pose la question :
I am doing a research project on frieze patterns (also called band patterns or border patterns). I know that there are exactly seven different types of frieze patterns, but I have been unable to find a proof for this. If you could tell me this proof, or tell me some internet sites on which I can find material on this, I would be very grateful.
Chris Fisher lui répond.
Concurrent Lines in a Triangle 1998-08-10
Chris Woolf pose la question :
The question is Name four types of concurrent lines, rays, or segments that are associated with triangles.
Chris Fisher lui répond.
Two Problems 1998-07-28
James Pulver pose la question :
How do you solve these problem? If log abc=16 and log ac=12 , find b. (The logs are log base 10.)
and
If a and b are real numbers, i^2 = -1 and (a+b)+5i=9+ai what is the value of b?

Jack LeSage lui répond.
Area and Volume 1998-07-28
James Pulver pose la question :
I am going into 12th grade and am practicing for the SAT II. I have come across a problem that I cannot solve. It states that the front, side , and bottom faces of a retangular solid have areas of 24 square centimeters, 8 square centimeters, and 3 square centimeters, respectively. What is the volume of the solid. I need to know how to solve similar problems so is there a formula to go from area to volume?
Jack LeSage lui répond.
Parabolas 1998-07-24
Danica pose la question :
how do you find the focus, vertex, and directrix of 4x-y^2-2y-33=0
Penny Nom lui répond.
Volumes of Revolution 1998-07-24
Lorraine Wall pose la question :
I'm on the section fpr The Computation of Volumes of Solids of Revolution and the following question is giving me problems:

-Consider the region in the first quadrant bounded by the x-and y-axes, the vertical line x=3, and the curve y=1/(xsquared + 3) I can determine the volume of the solid by rotating the region about the y-axis using the shell method but I can't seem to be able to get started with the volume when rotated about the x-axis.
Harley Weston lui répond.

Snake Eyes 1998-07-20
Would you please advise me what the probability is of rolling snake eyes on a pair of dice is? My recollection is 1 out of 6 multiplied by 1 out of 6 = 1 out of 36 is this correct?
Jack LeSage and Penny Nom lui répond.
Solving Quadratics 1998-07-16
Fred Goodrich pose la question :
I need a step by step lesson on solving quadratic equations.

Thank you,
Penny Nom lui répond.

Calculus problems 1998-07-13
Lorraine pose la question :
I'm stuck again. Can you help?

This involves integration using the method of partial fractions

the integral of:
7x(to the 5th) - 2x(cubed) + 3 dx
--------------------------------------
x(to the fourth) - 81

Do I have to do long division to reduce the numerator to the fourth power?

the integral of:
4- 16x +21x(squared) + 6x(cubed) - 3x(fourth) dx
----------------------------------------------------
x(cubed)(x - 2)(squared)

Lorraine
Harley Weston lui répond.

Percentages 1998-07-10
Adam pose la question :
Hi,
I would like to know the basics of percentages. It is all rather confusing to me.I have excelled in math but want to be ready next year for more advanced math.

What is Percentages?
Penny Nom lui répond.

Social Security Numbers 1998-07-07
Valerie Lucas pose la question :
How many social security numbers are possible?

the answer is 10^9

why isn't the answer 9^9?
Harley Weston lui répond.

A Calculus Problem 1998-06-28
Lorraine pose la question :
I'm a post-secondary student taking calculus by correspondence. I'm stuck on the following question (and similar ones) Can you help?

Evaluate the following indefinite integral:

d(theta)
----------
1 + sin (theta)

(It says to multiply both numerator and denominator by: 1 - sin(theta)

Thanks
Lorraine
Harley Weston lui répond.

15 to the zero 1998-06-24
Mike Husken pose la question :
My daughter has the problem: 15 with an exponent of zero=1. Could you help explain why? I would appreciate an answer soon as she has class tomorrow.
thanks,

Penny Nom and Patrick Maidorn lui répond.
Difference of squares 1998-06-23
Kristen Smelsky pose la question :
Solve the following using a difference of squares:

4x(squared) minus 4xy plus y(squared) minus m(squared) plus 2m minus 1
Penny Nom lui répond.

The Birthday Problem 1998-06-12
Josh Skolnick pose la question :
if you are at a party what is the least amount of people that have to be there to have at least a 50% chance of having 2 people with the same birthday? and how do you get the answer thank you in advance

josh
Harley Weston lui répond.

Rolling a seven 1998-06-11
Bruce Thompson pose la question :
What is the probablity of rolling two dice and it coming out as seven?

a) 1/6
b) 1/36

please give me the correct awnser and explain please.
Harley Weston lui répond.

Grade 9 Algebra 1998-06-07
Tarah Kostenko pose la question :
I am a grade 9 student and I cannot figure out how to solve these two similar problems. can you please help?
-3(y-1/2)=1/2 also -2/3(x + 1)=6
I don't come up with the same answers as the book and I can't figure out what I'm doing wrong.

Thank you,

Harley Weston lui répond.

A Logic Problem 1998-06-07
Anthony Bacigalupo pose la question :
My name is Anthony Bacigalupo and I take Sequential ][ Math and am taking a practice regents. When doing a logic problem, I encountered the following statements, where I am trying to prove P ( I left out steps unrelated to the question)....
Chris Fisher lui répond.
A trig limit 1998-05-28
Ann pose la question :
This problem is a calculus 1 limit problem-high school level. I'm teaching myself calc over the summer and I'm already stumped.

find the limit

 lim sec^(2)[(sqrt2)(p)]-1 p-->0 --------------------- 1-sec^(2)[(sqrt3)(p)] 
I'm Ann.

Harley Weston lui répond.
Sequences and series 1998-05-27
Michael Le Francois pose la question :
The sum of the first ten terms of an arithmetic series is 100 and the first term is 1. Find the 10th term.

The common ratio in a certain geometric sequence is r=0.2 and the sum of the first four terms is 1248 find the first term.
Penny Nom lui répond.

Trigonometry history 1998-05-26
Joeseph Huckler pose la question :
Can you please tell me some history of the trigonometric ratio Tangent? who discovered it? when was it discovered and some other useful info...
Penny Nom lui répond.
A Place Value Curiosity 1998-05-25
Ed pose la question :
I was visiting with an elderly gentleman this afternoon. He showed me this curiosity and then asked if I could explain it to him. Can you provide an explanation of why the 9 or multiple of 9 keeps occurring in this procedure? Choose any number, say 125 and add the digits to get 8. subtract the 8 from the 125 and the result is 117. Add the digits in 117 to get 9. Subtract the 9 from the 117 to get 108. Add the digits in 108 to get 9. If this procedure continues a 9 or a multiple of 9 reoccurs. What is the mathematical explanation behind this happening?
Denis Hanson lui répond.
The Fourth Dimension 1998-05-24
Whitney Page pose la question :
Okay, here goes all my effort to try to explain shat I'm trying to ask of you. It's about something I read in a book called A WRINKLE IN TIME, by Madeline L'Engle. It's called tesser, or tesseract.

It talks about first diminsion, a straight line, second diminsion, a flat square, and third diminsion, a square with sides, front and back, top and bottom.

I can picture all of that. Then it says that fourth diminsion is when you square the three diminsional square. It also described the fourth diminsion as time. I can't figure out how that can be. Then it says...
Chris Fisher lui répond.

Percentage Question 1998-05-18
Eddie Knox pose la question :
Example: If I have a recipe calling for 16 ounces of 4% vinegar (vinegar which has been diluted with water to a strength of 4%), and all I have on hand is 16 ounces of 5% vinegar, how much water should I add to decrease the strength to 4%, before measuring the 16 ounces to be used.

I'll appreciate any insight and help.

Thank you so much!
Harley Weston lui répond.

Graph question 1998-05-12
Rose Seminary pose la question :
Why is the point of intersection of two lines the solution to the corresponding system of equations?
Penny Nom lui répond.
Isosceles trapezoid formula 1998-05-12
Donna McMullin pose la question :
The teacher of Gifted and Talented Math has been trying to locate the formula for anisosceles trapezoid and we can't find it anywhere. Could it be the same formula for that of a parallelogram ? Please advise.
Walter Whiteley lui répond.
Area Calculation 1998-05-05
Jessica pose la question :
There's a question I have that I hope you can answer about calculating area.

It seems to me that common sense says that if you have say 100 meters of fence, the area you can enclose should be a constant. Yet the math says it is not so. For example if you build a rectangle 10x40 the enclosed area is 400 square meters. But if you build a rectangle 5x45 then the area is 225 square meters, even though you've started with the same amount of fencing.

I know this is true, but can anyone explain IN ENGLISH why this is so?
Harley Weston lui répond.

Pyramid 1998-05-04
Lisa Nathan pose la question :
How do you find the area of a pyramid?
Harley Weston lui répond.
Mathematical Arrays 1998-05-01
Gene Lanctot pose la question :
Could someone please explain what a mathematical or arithmetical array is? The array in question is used in grade three math in Ontario. I would also like to know what its purpose is.
Harley Weston lui répond.
Multiplying by Nine - Chismbop Style 1998-04-27
Noria Jones pose la question :
About a year ago a grade 5 teacher at my son's school taught the children how to multiply the 9 times table on their fingers quickly.

It was part of a kind of finger math kind of thing...
Patrick Maidorn lui répond.

Logic and Matrix Instruction 1998-04-24
Robin Booker pose la question :
I need assistance with instruction strategies to teach the construction of a matrix, solving a logic problem. Providing instruction in the construction of a simple matrix , no problem. However, I stumpted on this one.

Five players were chosen as All Stars at the basketball banquet. Based on the following clues, find the player's name, team, uniform color and number of points scored....
Harley Weston lui répond.

Mean and Standard Deviation 1998-04-22
Kit pose la question :
i have a problem of maths.
i think the level of the question is secondary. question: Find the mean and the standard deviation of the numbers:1, 3, 4, 5, 7. i hope u solve this question.
thank you so much!

Harley Weston lui répond.
Using your fingers 1998-04-21
Ian Sutherland pose la question :
My 7-year-old son, in Grade 2, constantly uses his fingers to count.  I know for now this is a useful crutch but at what point should he stop?
Diane Hanson lui répond.
Hour Hand Movement 1998-04-19
Chris and Angela Bradley pose la question :
My wife and I are haveing an argument over the answer to this question, what is the total number of degrees through which the hour hand of the clock moves in 3 hours and 18 minutes?
Thanks in advance.

Chris Fisher lui répond.
A Car Wash 1998-04-04
Lisa Gotimer-Strolla pose la question :
Al washes a car in six hours.
Fred washes a car in eight hours.
How long will it take them to wash a car together?

Harley Weston lui répond.
Seed Problem 1998-03-26
Jody A. Johnson pose la question :
Seed Problem: The height of an amazing plant grown from a seed varies linearly with the time it has been in the ground. After six days it is 6cm tall and after 60 days it is 15.8m (1580 cm) tall.
  1. Write the particular equation giving the height as a function of time.
  2. Find the intercepts and explain them.
  3. What would be the height in one year?
  4. How long would it take for the plant to grow to a height of 1km?
I'm having a problem with this equation. Could you please help. Thank you.

Penny Nom lui répond.
The day of the week, July 24, 1837 1998-03-21
Colleen K. pose la question :
What day of the week (Mon. Tues. Wed. etc...) was July 24th, 1837?
Chris Fisher lui répond.
Curvature of the Earth 1998-03-16
Robert Dyck pose la question :
How can I find the curvature per mile of the earths surface? What is it?
Harley Weston lui répond.
The Largest Factor 1998-03-15
Senthuran Nadarajah pose la question :
When each expression is evaluated for different values of n, the answers will differ. For each expression, find largest natural number that will divide the result for all natural number values of n.

n^5 - 5n^3 + 4n
Harley Weston lui répond.

Matrices 1998-03-10
Ksya pose la question :
  1. A and B are matrices. If A^n=B^n, can we say A=B or det(A)=det(B) or det(A)^n=det(B)^n ? Any conditions ???

  2. If B^(-1) is the inverse of B, where B is a matrices. Can we say [(B^(-1))^n][B^n]=I, where I is identity matrices? Any conditions???

Doug Farenick lui répond.
Clock Arithmetic. 1998-03-09
Joann Dixon pose la question :
What is clock mathematics?
Patrick Maidorn lui répond.
Area of a Triangle. 1998-03-05
Amanda pose la question :
How do you figure out the area of a triangle? You already have the perimeter and height
Penny Nom lui répond.
Y-intercept 1998-02-27
Don Trumpet pose la question :
What is the Y-intercept for the problem:Y = -2(x+2) + 9
Harley Weston lui répond.
Pay Phone Problem 1998-02-26
Shameq pose la question :
Hi, I've been given a problem that I'm having some trouble with. I'd really appreciate any help. Here's the question (it's called the Pay Phone Problem)

A pay phone will take only 10p, 20p, 50p, and £1 coins"(It's British).

A woman has plenty of 10p and 20p coins. She has no other coins. She can put the coins into the pay phone in any order.

INVESTIGATE the number of different ways, she could put the 10p and 20p coins into the pay phone.
Penny Nom lui répond.

The origin of angles 1998-02-24
Marc Poulin pose la question :
I'm currently teaching angles to students in grade 10 and I've been asked what's the origin of the terms degrees, radians and gradians.

I know that the radians come from the sexagesimal numerical system of the Babylonians but my kids wanted to know dates and persons who would have brought these terms first.
Harley Weston lui répond.

Tessellations of non-polygons 1998-02-24
Ellen Goldwasser pose la question :
Hi! My name is Ellen Goldwasser. I'm a seventh grade student and I'm doing a prodject on tessellation. My question is: why will certain shapes (not polygons) tessellate? Thanks for your help!
Penny Nom lui répond.
Tangrams 1998-02-24
Allison pose la question :
Do you know the story behind the tangram? I know that it is a Chinese puzzle about 200 years old. If there is a story about its creation, I would love to share it with my 7th graders. Thanks.
Diane Hanson and Penny Nom lui répond.
(50^20)(20^50) 1998-02-24
fion pose la question :
50 power of 20 X 20 power of 50?

How many zero can be found in the answer and why?
Penny Nom lui répond.

x^2 = ...444 1998-02-23
James Bauer pose la question :
What is the first interger that when squared ends in three 4's? (ex. x^2 = ...444)

Prove that there are no intergers that when squared end in four 4's (ex. x^2 = ...4444)
Penny Nom lui répond.

A Tightrope Walker. 1998-02-19
Amy Zitron pose la question :
A tightrope is stretched 30 feet above the ground between the Jay and the Tee buildings, which are 50 feet apart. A tightrope walker, walking at a constant rate of 2 feet per second from point A to point B, is illuminated by a spotlight 70 feet above point A....
Harley Weston lui répond.
The sum of the angles of a triangle is 180 degrees 1998-02-19
Quin Liu pose la question :
How do you prove that the sum of the angles of a triangle is 180 degrees? Is there a proof? what is it?
Chris Fisher lui répond.
Graph Distortion 1998-02-19
Dana Steffan pose la question :
What exactly is graph distortion? I have to explain it for a project and I can't seem to find anything on it.
Penny Nom lui répond.
Intersecting Lines. 1998-02-10
Erik Heppler pose la question :
My typewriter frequently makes mistakes. Suppose I gave you the following system of equations to solve:

35.26X + 14.95Y = 28.35
187.3X + 79.43Y = 83.29

When I looked back, I realized that I meant to use 14.96 as the "Y" coefficient in the first equation instead of 14.95. Solving the system using 14.95 and then solving another system using 14.96 with all other values the same both times results in the intersection points (1776, -4186) and (-770, 1816) respectively.
How can that be?
Penny nom lui répond.

The Earth's Arc 1998-02-06
Robert Dyck pose la question :
How do I find the arc/mile of the earths surface? What is the arc?
Harley Weston lui répond.
Roman Numerals 1998-02-05
Dawn Hilgenberg pose la question :
How would I read a Roman Numeral such as LXII? Does the L in front make the X equal a lesser amount? We have been discussing how to read these and I can find no information about how to read an extended Roman Numeral problem. Help!!
Harley Weston lui répond.
Area of a triangle. 1998-02-01
Jodi Blucher pose la question :
Is there a formula for the area of an equilateral triangle knowing the length of the sides?
Chris Fisher and Harley Weston lui répond.
Two Inscribed Trapezoids 1998-01-27
James pose la question :
A hexagon inscribed in a circle has three consecutive sides each of length 3 and three consecutive sides each of length 5. The chord of the circle that divides the hexagon into two trapezoids, one with three sides each of length 3 and the other with three sides each of length 5, has length equal to m/n, where m and n are relatively prime positive integers. Find m+n.
Haragauri Gupta lui répond.
Divisors of 6n 1998-01-26
James pose la question :
If n is a positive integer such that 2n has 28 positive divisors and 3n has 30 positive divisors, then how many positive divisors does 6n have?
(a) 32 (b) 34 (c) 35 (d) 36 (e) 38

Penny Nom and Haragauri Gupta lui répond.
The two-digit numbers from 10-99 1998-01-21
Alexis Riddle pose la question :
My name is Alexis. I'm a student in 8th grade and I'm taking Algebra I Honors. My question is: In a string of numbers, two adjacent digits are considered as a two-digit number. For instance, the string 11012 contains the numbers 10, 11, and 12. What is the number of digits in the smallest string that contains all of the two-digit numbers from 10-99? Please help and thank you for any assistance you can give me.
Penny Nom lui répond.
The Factor Theorem 1998-01-18
Dhruv Bansal pose la question :
Hi, I'm a ninth grade student doing a math project for school. I'm trying to learn about various ways of solving 3rd and 4th degree polynomial equations using the remainder theorem, the factor theorem, and synthetic division. The books I have all mention x - r, which I know nothing about, not even how to get it.

I would really appreciate any information on this. Thanks.

Dhruv Bansal
Penny Nom lui répond.

Polynomials 1998-01-13
Sarah Storkey pose la question :
Hi, My name is Sarah, My question is at the junior level.

My question is, what is a polynomial?
Harley Weston lui répond.

Quadratic Graphs 1998-01-13
Simon Batten pose la question :
How does varying the values a,b and c affect the graph of
y=ax2 + bx + c?

Harley Weston lui répond.
Greatest Common Factor. 1998-01-09
Percy Stribling pose la question :
how do you figure out what the greater common factor is?
Penny Nom lui répond.
Bathtub 1998-01-04
Jeffrey Yau pose la question :
A bathtub, with two taps, can be filled in 20 minutes using only the cold water tap. It can be filled in 30 minutes using only the hot water tap. The flow of each tap is not changed when both taps are turned on. It takes 24 minutes to drain the full tub. Starting with an empty tub and the drain plug in place, the cold water turned on. Five minutes later the hot water is also turned on, and five minutes after that the drain plug is removed. How many additional minutes, after the plug is removed, would it take to fill the tub?
Harley Weston lui répond.
Find the Numbers. 1997-12-28
Sandy C pose la question :
The sum of the squares of two numbers is 53. Twice the greater, minus the lesser is 11. Find the numbers.
Penny Nom lui répond.
Trigonometric functions 1997-12-21
Calvin Cheng pose la question :
My name is Calvin and I have a year 12 question for you to help me with.

From a point S, the angle of elevation of the top of a tower due north of it is 20 degrees. From R, due east of the tower, the angle of elevation is 18 degrees. S and R are 100m apart. Find the height of the tower.
Harley Weston lui répond.

(-2)^x 1997-12-12
Ken Bokinac pose la question :
During our math class last week we came accross an equation that we could not graph we were wondering if you could help us try and graph it. The question is:

y=(-2)^x
Harley Weston lui répond.

Calculating the Intersection Point. 1997-12-10
Milton Parsons pose la question :
Given 2 lines through (x1,y1),(x2,y2),and (x3,y3),(x4,y4). Can you give me a good formula for calculating the intersection point. I would greatly appreciate it.Thanks.
Chris Fisher and Penny Nom lui répond.
Pythagorean Triples. 1997-12-04
Shameq Sayeed pose la question :
I've got a couple of problems which I hope you'll be able to solve for me.

I'm investigating pythagorean triples, and I have found a trend for the triples themselves, and thus have been able to form a general equation, i.e. a=2x+1, b=2x^2+2x, and c=b+1. Now, I sure this equation works, because I've tried it out and have come up with triples that adhere to a^2 + b^2 = c^2. But I was wondering WHY c=b+1. Is it possible to have c=b+2, and if not why not? THAT is the first problem.
Chris Fisher lui répond.

Shimin's Geometry Problem 1997-12-02
Ong Shimin pose la question :
ABCD is a rectangle. X and Y are the midpoints of BC and CD respectively. W is a point on AB such that AW : WB = 2 : 1. Z is a point on AD such that AZ : ZD = 2 : 1.

WY intersects XZ at O. If the area of triangle WOZ is 84 centimeters squared, find the area of triangle XOY.
Chris Fisher lui répond.

Limited area and unlimited perimeter. 1997-11-28
Rosa pose la question :
There is a figure, it has unlimited perimeter but has limited area , what is the figure and how to draw it ?

Thank you very much!
Harley Weston lui répond.

Ratios. 1997-11-26
Jennifer Kim pose la question :
I am a grade 12 math student who would like to know if there is an easy way to solve

In a school the ratio of the number of Grade 11 students to the number of grade 12 students is 4:3. If there were 5 fewer students in grade 11 and 3 more students in grade 12, the ratio would be 7:6. How many students in each grade?
Penny Nom lui répond.

A Problem with Logs. 1997-11-26
Herman pose la question :
Given log 24=a, log 25=b and log 26=c, express log 39 in terms of a, b and c.
Penny Nom lui répond.
Guess and Check 1997-11-25
Don Ramey pose la question :
Hope you can help !!!! my daughter is in the 4th grade.. she has brought home a homework paper and the subject is problem solving. she does not understand what is expected of her. I have tried to help, but I do not understand either.

She is to use the Guess and check Strategy.

Ben knows 100 of his neighbors by name. Ten are fish. The rest are frogs and turtles. He knows the names of twice as many turtles as frogs. How many turtles does he know by name.?

Please help by explaining the guess and check strategy for a problem like this.
Diane Hanson lui répond.

Division by a fraction. 1997-11-21
Roger Marchegiano pose la question :
I am interested in a solution to the following extra credit problem for my son in Geometry. We have been unable to produce a satisfactory response:

Show a geometric representation of the division of fractions algorithm, (When you divide fractions you multiply the numerator by the reciprocal of the denominator).
Penny Nom lui répond.

A geometry problem 1997-11-20
Herman pose la question :
When produced, two equal chords AB and CD of a circle meet at P in an angle of 24 degrees. If H is the mid-point of AB and K is the mid-point of CD, calculate the size of angle HKD.
Penny Nom lui répond.
Driving me CRAZY. 1997-11-17
Billy Tran pose la question :
Write a two digit number (both digits different and neither equal to zero) and then express the same number but now composed of the same two digits in reverse order with some mathematical symbol (+, -, *, /, roots, !, or exponents). for example: 25 = 5^2. Now give me another.

Hope you get this, cause its driving me CRAZY
Penny Nom lui répond.

Octants 1997-11-10
Jason Watkins pose la question :
I know which octant is octant 1 because all variables are positive. How do we number the other octants?
Harley Weston lui répond.
Negative Primes. 1997-11-10
Leah Zucker and Paul Michael pose la question :
I have received the following question via e-mail from my granddaughter: "Can negative numbers (like -7) be prime? If not, why not?"
Chris Fisher lui répond.
Multiplying imaginary numbers. 1997-11-03
Jim Catton pose la question :
Here is the question:

(square root -2) x (square root -8)

My algebra suggests two possibilities .
.
.

Walter Whiteley, Chris Fisfer and Harley Weston lui répond.

Pi 1997-10-31
Ryan McKinnon pose la question :
What Is Pi?
Chris Fisher lui répond.
Roman Numerals 1997-10-31
Mark Curts pose la question :
I am looking for some resources for teaching Roman Numerals. I would like to expand upon the basic concepts, by locating some addition, subtraction, multiplication or division problems written with Roman Numerals.

--
Mark Curts
Chris Fisher lui répond.

Some Calculus Problems. 1997-10-30
Roger Hung pose la question :
  1. What real number exceeds its square by the greatest possible amount?

  2. The sum of two numbers is k. show that the sum of their squares is at least 1/2 k^2.

  3. .
    .
    .

Penny Nom lui répond.
Two Questions 1997-10-28
Melissa Kelley pose la question :
I would appreciate any help you could give me.
  1. Why isn't 1 a prime number?

  2. How can the absolute value of a number be negative?

Penny Nom lui répond.
Fractions 1997-10-20
Rebecca Henry pose la question :
When we add fractions, we find a common denominator and add the numerators When we multiply fractions, we simply multiply both numerators and denominators with no regard to commonality.
  1. Why do we not have to find a common denominator when multiplying?

  2. Why do we multiply both numerators and denominators?

Chris Fisher lui répond.
Diagramming Powers 1997-10-15
David Fill pose la question :
I am a teacher in Massachusettes. We have been diagramming numbers such as two to the third (a 3-D cube). One of my students asked me how you would diagram two to the fourth. I have searched through all of my teachers books and cannot seem to find the answer to this question. Is there a way to diagram this? If there is, how would you do this?

Your help would be greatly appreciated.
Penny Nom lui répond.

How many intersections? 1997-10-08
James pose la question :
(a) A collection of eight points, no three collinear. If lines are drawn between each pair of these points, how many points of intersection would there be?

(b) what would your answer have been in part (a) if there had been n points to start with?
Chris Fisher lui répond.

Polynomials 1997-10-07
Sheryl and Jeff pose la question :
I'm a math teacher in Jerusalem, Israel.

I'm teaching about graphing polynomial functions in a pre-calc class. A student asked me what they're good for. I couldn't give her a good example. Do you have one. Thanks.
Penny Nom lui répond.

Histograms. 1997-09-26
David Wilson pose la question :
I need some help to teach my daughter the functions and the techniques involved in solving histograms. She is in the 7th grade and is in a prealgebra class.

She was give these as homework, however there is no section in her book explaining what a histogram is or how to solve them.
Thanks!
Penny Nom lui répond.

Cos(x) Cos(2x) Cos(4x)=1/8 1997-09-24
Tan Wang pose la question :
How many distinct acute angles x are there for which cosx cos2x cos4x=1/8?
Chris Fisher Harley Weston and Haragauri Gupta lui répond.
A Geometry Problem 1997-09-18
Rebecca Henry pose la question :
A circle is centered at the vertex of the right angle of an isosceles triangle. The cirlce passes through both trisection points of the hypotenuse of the triangle. If the length of a radius of the circle is 10, find the area of the triangle.
Chris Fisher Harley Weston lui répond.
A Trigonometric Limit 1997-09-18
Brian Ray pose la question :
What is the limit, as x approaches 0, or tan^23x/x^2? (read, tan squared 3x over...)?
Harley Weston lui répond.
Imperial System of Measurement. 1997-09-17
Judy Pardilla pose la question :
Please also give the solution to the answers. Thank you.
  1. If a room is 12 feet by 15, how many square yards are there?

  2. If a single roll of wallpaper will cover 30 square feet, how many single rolls will it take to cover a wall 8' x 15'?

  3. If ceramic tiles are 8" x 8", how many tiles would it take to cover an area 4' x 6'?
If possible, can you e-mail me a table for imperial measurements. Thank you!

Penny Nom lui répond.
Rowing on the Charles River. 1997-09-17
Fawwaz Muraisi pose la question :
On the Charles River in Boston, the Harvard bridge and the Longfellow bridge are 1 mile apart. The MIT crew starts rowing upstream at the Longfellow bridge. As the crew passes under the Harvard bridge, the coxswain's hat falls into the river. Ten minutes later, the coxswain notices and turns the boat around instantaneously. He has t he crew row back to get it, rowing at the same constant rate. By the time the team reaches the hat, they are back at the Longfellow bridge.

How fast is the river flowing?
Harley Weston lui répond.

A Limit Problem 1997-09-16
Robert Reny pose la question :
what is the limit, as x approaches 0, of 3x/2x-[x]? [] means absolute value.
Harley Weston lui répond.
Billions and more! 1997-09-15
Mahabir B. Gupta pose la question :
I would like to know how you americans write the number 1 billion.

Do you say "One thousand million"..can you answer by giving me examples?

1,000,000----> 1 million
1,000,000,000---->1 billion

Why is it that in spanish it is different?
Penny Nom lui répond.

Integer Problems. 1997-09-15
Eric Kowalsky pose la question :
I have some intergers I can't solve. Please help me solve them! Please show me how you got the answer.
  1. 5(-4)-[3(-6)+(-3)-4(2(-4)-7)]+3(-8)=

  2. -2[-7-3(4)+5-2(-1)]+3(-6+8)=

  3. 4[-6(-2-7)-5(7+2)]=

  4. -7(-4)-2[-3(-4+6)+6(7-3(-4))]
P.S. Thank you very much.

Harley Weston lui répond.
The Range of a Function. 1997-09-12
Karel Marek pose la question :
Math Is Book 6 (Ebos/Tuck) question 5(b) gives a surprising answer at the back of the book..

The question is:
Indicate the domain and range for this: y = sqr(x-9) (Square root of)

The answer for the domain is x>=9 which is not surprisingly, but the range is y>=0, yER ... which I could understand if you were not allowed to transform the equation into x as the subject..

But all example on the facing page DO TRANSFORM the equation at will with x and/or y as the subject..

Can you explain this...
??
Chris Fisher lui répond.

Triangular Numbers. 1997-09-08
Rachel pose la question :
Show visually that the square number 16 is the sum of two triangular numbers. Which two?
Penny Nom lui répond.
Definitions 1997-09-08
SohoGirl13 pose la question :
I am an 8th grader. my e-mail address is SohoGirl13@aol.com. I have a question: what are the associative, communitive, and distributive properties?
Harley Weston lui répond.
A Finite Math Question. 1997-09-07
Angela L. pose la question :
How many three-digit numbers can be formed using only the numbers 1 to 7 if the number 2 must be included?
Penny Nom lui répond.
Prime Numbers 1997-09-04
Jack Bedard pose la question :
Hi. I have a real stupid question

What are prime numbers?

My name is Jack Bedard and I am in grade 5.
Penny Nom lui répond.

Square Root History 1997-08-29
Carlos Montecel S. pose la question :
I need find information over the "Square Root History", Could you help me?
Harley Weston lui répond.
Two Questions 1997-08-28
Faye Tan pose la question :
I am a trainee teacher. I would appreciate it very much if you could help me solve the following two problems which I think are meant for students at middle grade.

1. If a hen and a half lays an egg and a half in a day and a half, how many hens are needed to lay a dozen eggs in one day?

2. There are fewer than 200 passengers on a train. If they get off in pairs, one passenger will be without a partner. If they get off in groups of 3 or 4, there will still be one passenger left by himself. However, if they get off in groups of 5, no one will be left by themselves. How many passengers are there on the train?
Penny Nom lui répond.

The Length of a Chord. 1997-07-26
Nathan Arthur pose la question :
Picture a 9 inch diameter circle. Inside that circle is a 6 inch diameter circle tangent to it. Then, tangent to both circles is a 3 inch diameter circle. So there are three circles, two smaller ones inside a big one, all of them just touching but not overlapping.

Now picture a chord on the 9 inch circle that is created by making a line that is tangent to both the 6 and the 3 inch circles and extending it to the edge of the 9 inch circle.

I need the length of that cord.
Chris Fisher lui répond.

A Question About Pi. 1997-07-08
Mike Chan pose la question :
I have read the section Repeating Decimals in your data base. It mention that 1/17 has at most only 16 repeating digits. But, why does "pi" have an infinite number of digits (and not repeating ).
Penny Nom lui répond.
Finding the Mine 1997-06-23
Billy Law pose la question :
Tom is gold prospector. On his last trip out from town, he headed 35 degree South of West to a lake where he had lunch. The lake was 24 km out of Town. He then headed due East for 35 km before Doubling back on bearing of 15 degree South of west for 20 km to reach his mine. By converting to Cartesian coordinate before doing vector additions do the following:

a) Calculate the position of the mine from town in term of a distance and a direction.
...
Harley Weston lui répond.

A problem with arccos. 1997-06-09
Vanessa Chan pose la question :
Prove: arc cos4/5 + arc cos (-5/13) = arc cos (-56/65)
Harley Weston lui répond.
The angle between two tangents. 1997-06-09
Felix Ho pose la question :
Two tangents are drawn from the origin to the circle (x)(x)+(y)(y)-4x-6y+9=0. If the angle between the tangents is m, fine the value of tan(m).

P.S. (x)(x)=square x
Harley Weston lui répond.

Y-axis 1997-05-29
Leah pose la question :
I know that the proper name for the X axis is the abscissa, but, what is the proper name for the Y axis?
Chris Fisher lui répond.
The General Equation of a Parabola 1997-05-28
Michelle pose la question :
My name is Michelle and I am a 10th grade student in algebra 2 w/ analysis. I am doing a report on parabolas and I need to know what the general equation is. I've looked in books and keep finding different ones! I also need to know how they can be used in nature.

Thank you so much for your time. I really appreciate it!

- Michelle
Harley Weston lui répond.

The Area of a Trapezoid. 1997-05-07
Mary George pose la question :
I am doing the area of trapezoids and mixed polygons and I was wondering if you can help me figure out this problem.

A line segment drawn parallel to a leg of a right triangle divides the other leg into segments of 3cm and 6 cm and the hypotenuse into segments of 5cm and 10 cm. The two figures formed are a triangle and a trapezoid. Find the area of each.

I would appreciate if you would email me back the solution.
Harley Weston lui répond.

Surface Area 1997-04-30
Amber Nobile pose la question :
The height of a cylinder is twice the diameter. Express the total surface area as a function of the height h.
Harley Weston lui répond.
A proof that e is Irrational. 1997-04-30
Peter Hall and Jenny pose la question :
We have a little mathematical problem... we need some help proving e is an irrational number!

We don't feel very confident in our formulas, so if You have the time to give us a little explanation we would be very grateful!!!
Doug Farenick and Penny Nom lui répond.

Solving a Trig Equation. 1997-04-28
Susan Harvey pose la question :
Hi I am a teacher and have a calculus problem that I have a solution to but it seems so involved that I would be interested to see if their were other solutions.

Solve for x, if x is from -90 to 90 degrees

tan2x = 8cos{squared}x - cotx
Chris Fisher Denis Hanson and Harley Weston lui répond.

Formulae for Surface Area. 1997-04-28
Gary Millward pose la question :
I'm trying to help my son with his Math homework (Grade 10) and he has to find the surface area of a cone and rectangluar pyramid. We have the formulas for the volume of these solids, but can't seem to locate the formulas for surface area.
Walter Whiteley lui répond.
A Monte Carlo Procedure 1997-04-23
Donna Hall pose la question :
A irregularly shaped object of unknown area A is located in the unit square 0<=x<=1. Consider a random point uniformly distributed over the square. Let X = 1 if the point lies inside the object and X = 0 otherwise. Show that E(X) = A. How could A be estimated from a sequence of n independent points uniformly distributed over the square? How would you use the central limit theorem to gauge the probable size of the error of the estimate.
Harley Weston lui répond.
Natural Logarithm Functions 1997-04-23
Rickson pose la question :
The following two questions are some of my son's homework that he is having trouble with......any advice or assistance would be appreciated.

(eX)5=1000.............the X and 5 are exponents

lnx + ln(x+3) = ln10

In each question the problem is to find x.
Harley Weston lui répond.

Square Roots and Functions. 1997-04-23
Ed pose la question :
1. In most texts the solution to a question such as square root x = -6 is

x is undefined.

Yet when teaching to solve
xsquared = 36
x = +6 or -6

There appears to be a contradiction here. My question is when, where and why do we use the principle square root, not both + and -? This often occurs as the extraneous root in the solution of radical equations and in stating the domain and range of functions involving square roots.

2. Are there any simple rules for determining whether equations are functions without graphing them and doing a vertical line test?
Harley Weston lui répond.

The Central Limit Theorem 1997-04-21
Donna Hall pose la question :
A skeptic gives the following argument to show that there must be a flaw in the central limit theorem:
We know that the sum of independent Poisson random variables follows a Poisson distribution with a parameter that is the sum of the parameters of the summands. In particular, if n independent Poisson random variables, each with parameter 1/n, are summed, the sum has a Poisson distribution with parameter 1. The central limit theoren says the sum tends to a normal distribution, but Poisson distribution with parameter 1 is not normal.

What do you think of this argument?
Neal Madras lui répond.

Proofs 1997-04-13
Daniel pose la question :
I'm having trouble understanding proofs. I don't know how to come up the answers on my own. I search through the book looking for the answer. I understand what they are doing, but I don't know how to do it.
Walter Whiteley lui répond.
The Division Bracket. 1997-04-09
Judy Riley pose la question :
A fellow teacher recently asked if I remembered the exact word for a division bracket (not the symbol with dots, the horizontal line in a fraction, or a solidus). I couldn't. Can you help?
Walter Whiteley and Harley Weston lui répond.
A Geometry Problem 1997-04-09
Gina M. Pisco and Rebecca Henry pose la question :
Three segments of 3, 4, and 5 inches long, one from each vertex of an equilateral triangle, meet at an interior point P. How long is the side of the triangle?
Richard McIntosh lui répond.
Equation of a line 1997-04-08
Susan Gregson pose la question :
I am a secondary school teacher. My students and I would like to know why the letters m and b are traditionally used to stand for slope and Y-intercept in the standard form of an equation. Was this an arbitrary choice? Who made it? Are the letters from Greek ot Latin words?
Harley Weston lui répond.
Graphing Inequalities of Conic Sections 1997-03-24
James Sheldon pose la question :
I'm trying to graph Systems of Conic Sections with inequalities, but I'm running into problems on which area to shade:
x^2+y^2 is greater than or equal to 16
xy > 4

So I graph these two equations, and then my teacher said to substitute a point into it but I'm still not sure how to do it...
Penny Nom lui répond.

The normal distribution. 1997-03-21
Donna D.Hall pose la question :
I am looking for a proof for the normal distribution.

I suppose "proof" was not a good choice of words. What I am looking for is a way to "derive" the normal distribution in simple terms so that the most average teenager can see the logic. Can you help me?
Harley Weston lui répond.

Why QUADratic? 1997-03-19
Paula Miller pose la question :
A student today asked me why a quadratic, with highest power of degree 2, was called a QUADratic. We're awaiting the answer with baited breath! :)
Chris Fisher and Walter Whiteley lui répond.
Mathematical Induction and the Derivative 1997-03-18
Shuling Chong pose la question :
"Obtain a formula for the nth derivative of the product of two functions, and prove the formula by induction on n."

Any educated tries are appreciated.
Penny Nom lui répond.

A Presidential Proof 1997-03-18
Greg Smith pose la question :
Which US president developed a proof for the Pythagorean Theorem?

Where can a copy of the proof be located?
Chris Fisher and Harley Weston lui répond.

The Real Pythagoras 1997-03-16
Michael Gaskin pose la question :
I am wondering if you have any information about Pythagoras and his accounts in math.
Chris Fisher lui répond.
Ajax, Beverley, Canton and Dilltown 1997-03-14
S. Johnson pose la question :
The following towns are placed on a coordinate system. Ajax at (-x,z), Dilltown at (-10,0), Canton at (0,0) and Beverly at (0,10). The roads from Beverly to Canton and from Canton to Dilltown are perpendiculat to each other and are each 10 miles in length. A car traveling at all times at a constant rate, would take 30 minutes to travel straight from Ajax to Canton, 35 minutes to travel from Ajax to Canton via Beverly, and 40 minutes to travel from Ajax to Canton via Dilltown. What is the constant rate of the car, to the nearest tenth of a mile per hour.
Chris Fisher and Harley Weston lui répond.
Names of the Polygons 1997-03-04
Manuel pose la question :
What do you call a 13 sided polygon?
Is there a list of the different names?

Walter Whiteley and Harley Weston lui répond.
0! 1997-03-02
Donna D. Hall pose la question :
I am looking for a quick and easy explanation as to why 0! is 1.
Walter Whiteley and Denis Hanson lui répond.
Area Between Two Sectors 1997-03-02
Rebecca Henry pose la question :
Points A,B,C,D,E,F are equally spaced on a unit circle. Arc CGE has a center A. Find the number of square units of area in the shaded region.
Walter Whiteley lui répond.
A Functional Equation. 1997-02-26
Ronald Lui pose la question :
Find all functions f:S --> S statisfying the two conditions:

1)f(x+f(y)+xf(y))=y+f(x)+yf(x) for all x and y in S

2)f(x)/x is strictly increasing on each of the interval -1
Saroop Kaul and Chris Fisher lui répond.

Equivalent Expressions 1997-02-26
Karyn Jones pose la question :
Josie says that s=n/(n+1) and s/(1-s)=n are two ways to write the same formula. Describe whether or not you agree with Joise. Explain how you made your decision.
Walter Whiteley and Penny Nom lui répond.
Some Circle Questions. 1997-02-25
Staci Vawser pose la question :
A circle with a radius of 10m is drawn. A chord is drawn across the circle. How is the area that is formed between the chord and the arc calculated?
Harley Weston lui répond.
Triangles, The Pythagorean Theorem and Pizzas. 1997-02-23
Sherryle Mathis pose la question :
I am a graduating senior presently teaching geometry as part of my student teaching. I will do my CUP on Right Triangles and Pythagorean theorem. I am looking for a fun activity as part of my unit plan.
Walter Whiteley lui répond.
Division by zero 1997-02-14
Linda Hood pose la question :
I am a college student and have been asked to explain and figure out why we can't divide by zero.
Chris Fisher lui répond.
When is ( n^3+1)/(mn-1) an integer? 1997-02-11
Ronald Lui pose la question :
Determine all ordered pairs (m,n) of positive integers such that ( n^3+1)/(mn-1)is an integer.
Richard McIntosh lui répond.
Circular Permutations 1997-02-05
Ed Varjassy pose la question :
I have an understanding of simple problems involving circular permutations but do not understand them when they start to have restrictions. Is there any advice you can give for these more complicated permutations.
Penny Nom lui répond.
Deriving the Quadratic Formula 1997-02-04
James pose la question :
How do you derive the quadratic formula? I know what it is, but the textbook doesn't say how to derive it.
Penny Nom lui répond.
Parabolic Mirrors 1997-01-28
Megan Wennberg pose la question :
Consider a ray of light that passes through a chord of a parabola (the chord is above the focus and parallel to the directrix), hits the parabola at a point (x,y) and is reflected through the focus. If d1 is the distance from the chord to the point of incidence (x,y) and d2 is the distance from (x,y) to the focus, can you prove that the sum of the distances d1+d2 is constant, independent of the particular point of incidence.
Penny Nom lui répond.
A donkey and his carrots 1997-01-28
Emily Lind pose la question :
There is a donkey who carries carrots. A farmer has 3,000 carrots to carry to the market. The market is 1,000 miles away. The donkey can only carry 1,000 carrots at a time and he eats 1 carrot every mile that he walks but this is only when he is carrying carrots. How many carrots can the farmer get to market by having the donkey carrying them?
Penny Nom lui répond.
Repeating Decimals 1997-01-24
Grant Reed pose la question :
Is there a way to tell that the repeating decimal for 1/17 has no more than 16 repeating digits?
Penny Nom lui répond.
Foci of an Ellipse 1997-01-22
David Gilliam pose la question :
How do I find the focii of the following equation? 4x^2 + 9y^2 = 36
Harley Weston lui répond.
Mathematics of Schedules 1997-01-16
Byron Krull pose la question :
I was asked if there was a mathematical method to work with schedules. The problem is this. There are 24 teams playing weekly on 4 sheets at 3 different times of the day as follows...
Denis Hanson lui répond.
Three Spheres 1997-01-14
Alan Schnerch pose la question :
Three spheres of diameter 2 are placed on a level surface so that each sphere touches the other two. A fourth sphere, also of diameter 2, is placed on top of the other three so that it touches all of the other spheres. The distance from the level surface to the highest point of the top sphere is . . ..
Chris Fisher and Harley Weston lui répond.
A triangle problem 1996-12-19
S. Johnson pose la question :
Given that Triangle ABC is a right triangle and Circle O is inscribed in it find the radius of Circle O, totally in terms of a, b, and c.
Penny Nom lui répond.
A trig problem 1996-12-13
S. Johnson pose la question :
sin t + cos t = 1/5. Find ALL exact values of cot t, given the original equation.
Harley Weston lui répond.
Roots of a Polynomial 1996-12-06
Paula Miller pose la question :
Why is the solution called a "root"? Why not just the "x-intercepts"?
Chris Fisher and Harley Weston lui répond.
Sides in a Regular Polygon 1996-12-06
Rick Moss pose la question :
If you are given the measure of each interior angle (162 degrees) of a regular polygon. How many sides does the polygon have?
Penny Nom lui répond.
A balance problem 1996-11-18
Jack N. Bussell pose la question :
There are 12 coins which look exactly the same, however one of them is heavier or lighter than the rest. Using a pointer balance scale, can you identify the odd coin and whether it is heavy or light in 3 weighings?
Harley Weston lui répond.
Pentominoes 1996-11-14
Sam Maraldo pose la question :
What is a pentominoe? I need to understand the concept and how/why it is used?
Penny Nom lui répond.
Trigonometry 1996-11-12
Evans pose la question :
Any idea who came up with some or most of the ideas involved in trigonometry?
Chris Fisher lui répond.
Smith, Rodriguez and Jones 1996-11-07
Rafayel Ambartsumyan pose la question :
On a train, Smith, Rodriguez, Jones are the fireman, brakeman, and engineer, but not in that order. Also aboard the train are three businessman who have the same names, a Mr. Smith, a Mr. Rodriguez, and a Mr. Jones. ..... Who is the engineer?
Penny Nom lui répond.
Height of a Hotel 1996-11-07
Irene pose la question :
"Irene" is to determine the # of floors in a hotel 500 feet up the street. Irene is on the 10th floor of an office building and can measure the angle of elevation to the top of the hotel, 57 degrees. Her view of the entire building is obstructed. If the street rises at an angle of 8 degrees from the office building to the hotel and the average distance between floors is 11 feet, how many floors are on the hotel?
Penny Nom lui répond.
Common Area of two sectors. 1996-11-06
Lynda Mow pose la question :
How do I find the area common to two intersecting circles of radii 8 ft and 10 ft if their common chord is 10 ft long?
Penny Nom lui répond.
Priority of operations 1996-11-04
Wallace pose la question :
What is the answer to this problem? Let x=-2 and y=3. Evaluate 12x / 2y (if the old division sign is used).
Chris Fisher lui répond.
Approximating pi. 1996-11-04
Ben Dixon pose la question :
How do you calculate Pi? Do you have to somehow combine the equation for a circle with the formula for the circumference?
Chris Fisher lui répond.
Approximating roots. 1996-11-04
Ben Dixon pose la question :
How do you calculate a square root? eg the square root of 2.

There is obviously some sort of successive approximation type algorithm for doing it to however many decimal places is required, but what is the algorithm?
Harley Weston lui répond.

The diameter of the sun. 1996-10-29
Lynda Mow pose la question :
What is the process for solving the following question? As viewed from earth, the sun subtends an angle of approx 32'. If the sun is 93,000,000 miles from earth, find the diameter of the sun.
Penny Nom lui répond.
A tangent to a circle is perpendicular to the radius at the point of contact. 1996-10-22
Rita Leung pose la question :
I wonder if there is any proof for this theorem - A tangent to a circle is perpendicular to the radius at the point of contact. If there is any proof for that, can you tell me please?
Chris Fisher and Harley Weston lui répond.
Could you tell me the name for the bar in a division problem? 1996-10-21
Linda pose la question :
Could you tell me the name for the bar in a division problem. Not the line with dots on either side but the line that divides the two numbers? My name is Linda. I am asking for my niece who is in 8th grade.
Chris Fisher lui répond.
What is the volume of a regular tetrahedron? 1996-10-21
Paul Bleier pose la question :
How does one calculate the volume and the height of a three sided pyramid formed by equilateral triangles?
Bruce Gilligan lui répond.
How many digits are there in 2^2520? 1996-10-07
Rita Leung pose la question :
A)The number 64 is a sq., a cube, and a sixth power because 64=8*8, 4*4*4, 2*2*2*2*2*2. Find the smallest integer greater than 1 that is a sq., a cube, a 4th, 5th, 6th, 7th, 8th, 9th and 10th power. I have found that the answer is 2 to the power 2520th.
B) How many digits are in the correct answer to part A? The answer is uncertain. It is either 758 or 759. Can you give me any ideas?

Penny Nom lui répond.
Why is lbs the abbreviation for pounds? 1996-10-03
Nancy Mutdosch pose la question :
What does lbs stand for? Why is it the abbreviation for pounds?
Chris Fisher lui répond.
Why is a circle divided into 360 degrees? 1996-09-30
Kurtis Kredo pose la question :
I was recently wondering why a circle has been divided in to 360 degrees. When I asked my physics teacher he could not think of an answer. His guess is that it probably has to do with people long ago using the base 6 number system. I have a small inkling that it has to do with easy conversion or usage with radians or grads.
Chris Fisher lui répond.
Divisibility of 2n choose n. 1996-09-24
Kathy Doan pose la question :
Can you prove that "2n choose n" is not divisible by 3, 5, and 7 for infinitely many n?
Penny Nom lui répond.
How many possible combinations of answers are there? 1996-09-20
David Bester pose la question :
Suppose there is a 12 question test. Each question can be answered only by true or false. Assuming that all questions are answered (i.e. none are left blank), how many possible combinations of answers are there? And what formula was used to arrive at the answer?
Denis Hanson lui répond.
Term definitions 1996-09-18
M. Seltzer pose la question :
A 7th grade algebra student would like the definition of the terms proper factor and perfect number.
The Centralizer lui répond.
How do you find out if a number is a composite or prime? 1996-09-16
Trish Feenstra pose la question :
Hi my name is Trish Feenstra. In grade 8. How do you find out if a number is a composite or prime if it is big like 37 529? Reply soon got a test on Friday the 13th
Denis Hanson lui répond.
Repeating decimals 1996-09-09
Alice pose la question :
What is the line called that is placed over the decimal to show that it is infinitely repeating?
The Centralizer lui répond.
Will this always yield a palindrome? 1996-08-28
Andy Golden pose la question :
My friend Justin Skywatcher, said that when his children were in 6th grade, they were taught that if you take any number, reverse it and add the two together, a palindrome will result. If not, continue performing the above operations, and a palindrome will eventually result. Will this always yield a palindrome?
Chris Fisher lui répond.
Thousands, millions, billions and trillions 1996-08-22
Blaine pose la question :
What are the names of the periods in groups of numbers like 123,456,789. I need to know the names of them for school. I already know the first ones: units thousands millions billions trillions.
Penny Nom and Diane Hanson lui répond.
Where do 2^x and x^2 intersect? 1996-07-23
Darin M Selfridge pose la question :
The intersecting points of y=2^x and y=x^2, graphed along with x^2=2^x, are obviously three... (2,4), (4,16) and (?,?). I am having problems figuring out the value, and even an equation for the (?,?). Can you help?
Harley Weston Chris Fisher lui répond.
How do you raise a number to an imaginary/complex power? 1996-07-03
Andy Golden pose la question :
How do you raise a number to an imaginary/complex power? I know how you raise "e" to a complex power, like e^(pi*i): cos pi + i * sin pi But what about numbers other than "e"? What if I want to raise 5 to the 2i power? How is that done?
Chris Fisher lui répond.
What are fractals and are they of any practical use? 1996-06-26
Ron pose la question :
What are fractals and are they of any practical use?
Chris Fisher lui répond.
Diagonals in a polygon 1996-06-18
Steven pose la question :
How many diagonals are there in a polygon?
Denis Hanson lui répond.
Show that this construction yields a rhombus. 1996-06-16
LennyB pose la question :
Hello, I have a problem. I doubt you can help me. If you have an isosceles trapezoid, and you connect the midpoints of the four sides of the isosceles trapezoid forming a quadrilateral, how do you prove that it's a rhombus in a 2 column proof??
Penny Nom lui répond.
a to the power zero 1996-06-03
Beti pose la question :
Why is a number to the power 0 equal to 1?
Harley Weston lui répond.
Prove that these two lines are parallel. 1996-05-29
Adam Piekarzewski pose la question :
Using parallel line theorems and side angle side etc. in triangle acd a line is drawn from point b on ac and point i on ad. another triangle fliped vertically and joined at d is named fdh, a line is drawn from point e on fd and point g on fh. ab = fg, ai = fe, ac || fh prove that bi || eg /- -/
Harley Weston lui répond.
How do you graph these inequalities? 1996-05-17
Robert pose la question :
How do you graph the inequalities 5+gg, and g+h>6 on one coordinate plane?
Harley Weston and Maxine Stinka lui répond.
How do you graph these equations? 1996-04-30
David Gamble pose la question :
How do you graph the equation x=3 on a x,y graph? Also how do you graph f(x)=-3x + 2 on the same graph?
Harley Weston and Maxine Stinka lui répond.
A coin problem 1996-04-16
Julie Hebert and Simon Hamel pose la question :
How many weighings would you need to find out which pile is fraudulent?
Penny Nom lui répond.
An application of Pythagoras' theorem 1996-04-09
Mike pose la question :
We'd like to know what practical applications there may be for the Pythagorean theorem.
Penny Nom and Maxine Stinka lui répond.
Area of an annulus 1996-04-04
Ryan Levering pose la question :
What is the area of this annulus?
Penny Nom lui répond.
Area=Perimeter 1996-04-02
Jason Pelowski pose la question :
When will the area and the perimeter of a right triangle be numerically equal?
Penny Nom and Maxine Stinka lui répond.
Square roots 1996-03-16
Terry King and John pose la question :
We are just curious about how to manually calculate square roots.
Harley Weston lui répond.
The impossible problem 1996-03-15
Shaun Reynolds and Jacob Hiatt pose la question :
How do you solve (the 6th root of x)+4=3?
Penny Nom and Maxine Stinka lui répond.
Cardano's method 1996-03-11
Mike Gorski pose la question :
What is Cardano's method for finding the roots of a cubic equation?
Harley Weston lui répond.
Grade nine problem solving 1996-03-11
Azmat Hussain pose la question :
Can math problems be actually fun and engaging?
Diane Hanson lui répond.
A trig identity 1996-03-11
Azmat Hussain pose la question :
Is there an easier/another way to prove the trig identity cos(a+b) = cos(a)cos(b)-sin(a)sin(b)?
Penny Nom lui répond.
Pronunciation 1996-03-05
Todd Stienhauser pose la question :
Is 123.4 pronounced "one hundred and twenty three and four tenths"or "one hundred twenty three and four tenths"?
Penny Nom lui répond.
Exponents 1996-02-25
Eric Cote pose la question :
I want to know why the grade six math books tell you that the little number at the top right of another number (exponent) is called the power, but the grade seven and up books tell you it's called the exponent?
Harley Weston lui répond.
Algorithms for roots 1996-02-22
Charles Hewitt pose la question :
I have seen an algorithm for finding the square root of numbers. Are there similar such algorithms for higher roots?
Harley Weston lui répond.
Prime numbers 1996-02-22
Charles Hewitt pose la question :
I would apprecaite it if you could share with me any algorithm to determine whether a number is prime.
Penny Nom lui répond.
Queue length 1996-02-22
Frank Fronhofer II pose la question :
How long is the toll booth queue?
Harley Weston lui répond.
e^(i*pi) = -1 1996-02-19
Matt Schneider pose la question :
Why is e^(i*pi) = -1?
Harley Weston lui répond.
Pascal's Triangle 1996-02-19
Richard pose la question :
Do you know of any resources that might help us make use of the numeric relationships in Pascal's triangle on a fairly simple basis?
Denis Hanson lui répond.
Neighbourhoods 1996-02-14
Robert pose la question :
What are neighbourhoods?
Harley Weston lui répond.
Euclid's Pythagorean proof 1996-02-14
Sean pose la question :
What is Euclid's proof of Pythagoras' theorem?
Harley Weston lui répond.
Stairs 1996-02-12
Marianne and Carrie pose la question :
How many ways can you run up a flight of stairs?
Denis Hanson lui répond.
What is the variance of the difference of two binomials? 1996-02-08
Chris Johnson pose la question :
My co-workers and I have come up with different estimates of the z-statistic, and are in particular disagreement over the calculation of Variance for this problem. I am trying to find out, with a five percent level of significance, whether the new form yields a higher rate of return than the old form. Any thoughts, comments, or solutions?
Harley Weston lui répond.
Converting to other bases 1996-02-06
Paul pose la question :
Converting base 10 numbers to other bases
Penny Nom lui répond.
Number of factors 1996-01-30
Chrissy pose la question :
What number has exactly 13 positive factors?
Penny Nom lui répond.
Trig identities 1995-11-30
Azmat pose la question :
Why do we work on the two sides of a trig identity separately?
Harley Weston lui répond.
(-3)x(-2) 1995-10-25
Azmat pose la question :
Why is (-3)x(-2) = 6?
Herley Weston and Ed Giesbrecht lui répond.
Complex numbers 1995-10-22
Jacquie pose la question :
Why should we teach complex numbers in high school?
Harley Weston lui répond.
Magic Square 1995-10-20
Marianne and Carrie pose la question :
How can an 8 by 8 square have the same area as a 5 by 13 rectangle?
Denis Hanson lui répond.
What is the golden section? 1995-09-17
Cindy pose la question :
What is the golden section of a line?
Denis Hanson lui répond.
 
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