1278 articles trouvés pour ce sujet.
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Calcul dun profil fictif |
2005-09-29 |
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Mr madry loïc pose la question : je suis actuellement en formation pour devenir dessinateur projeteur en BTP ; je rencontre un problème vis à vis d'une égalité qui normalement devrait mettre acquise ( elle doit être issue de thalès ou de l'égalité des proportion ?) cependant, je n'arrive pas trouver le fondement de cette égalité. pourriez vous m'aider à éclaircir cette relation fondamentale afin de poursuivre mon étude sur le calcul de profil en travers (pour les travaux publics) . Claude Tardif lui répond. |
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Opérations de base |
2003-07-05 |
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Anne-Marie pose la question : Je m'appelle Anne-Marie et je suis enseignante de 5e année à l'école Domaine des copains de Balmoral au Nouveau-Brunswick. Récemment, j'ai participé à un concours intitulé: Budweiser King Pack Nascar Hat Promo. Afin de réclamer le prix, qui est une casquette, je devais répondre à une question réglementaire. Il s'agissait d'une phrase mathématique qui se présentait comme suit: 4 x 26 - 24 / 8 = qui se lit: 4 fois 26 moins 24 divisé par 8 Claude Tardif lui répond. |
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A/B = C/D |
2002-03-06 |
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Un eleve pose la question : Démontrer que si A sur B et = à C sur D, alors AxD et = à BxC. Claude tardin lui répond. |
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Resolution of the equation f(x)=0 |
2000-04-01 |
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Naoufal pose la question : How can i evalf the equation f(x)=0 with f function . Can you ansear me in french thank you very much Claude Tardif lui répond. |
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Le salinon d'Archimèdre |
1999-03-11 |
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Don Craig pose la question : I am trying to find the English translation of "Le salinon d'Archimèdre" and would appreciate any help. This is a figure, presumably studied by Archimedes, created from 4 semi-circles. Since I can't draw it for you, I will try to describe it with the help of the 5 collinear, horizontal points below. . . . . . A B C D E A semi-circle is constructed on AE as diameter (let's say above AE). Two more semi-circles are then constructed with diameters AB and DE on the same side of the line AE as the first semi-circle (above it). Finally, a fourth semi-circle is constructed on diameter BD, this time on the opposite side of the line AE from the others (i.e. below the line). These semi-circles and the region enclosed by them constitute what is called in French "Le salinon d'Archimèdre". If you know the English name of this curve I would appreciate it if you let me know. Harley Weston lui répond. |
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Finding the area of a regular polygon |
2007-05-04 |
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Dana pose la question : We are trying to figure the square footage of a tetradecagon....sort of a round house with 14 sides that are 8 ft' in length. It has a height of 9 ft. How do we figure the square footage of this? Stephen La Rocque lui répond. |
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Strings of letters |
2022-04-25 |
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Javar pose la question : How many different combinations can I make with A 12 selection list but only
using A&B
Example:
A,B,A,B,A,B,A,B,A,B,A,B
A,B,B,A,A,B,B,A,A,B,B,A
B,B,A,A,B,A,B,A,B,A,A,B penny Nom lui répond. |
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Roll of film |
2021-11-20 |
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Brian pose la question : Trying to create a formula to calculate the build up on a roll of film is calculated. Except instead of of a roll, it's essentially a rectangle with two semicircles on each at the end.
Example: I start with a 6" diameter core on each side, and I start winding .005"
thick film on the core. The distance between the center of those cores, length of the inner rectangle is 7.125.
If I continue to do this for a total length of film of 3000 feet, what will the
roll length and width be.
So what I need is the formula to perform this type of calculation.
Can you help me? I want to be able to plug the formula in a spread sheet and to be able to input a core diameter, a film thickness and a total length and the length between the center of the two cores(which is the inner rectangle's length I'm assuming).
Thanks Harley Weston lui répond. |
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30 % off |
2021-09-07 |
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Corrine pose la question : When I am shopping for clothing that is for sale, the advertisement may say the item is 30% off. The original price was $70. How much would it now be? (how do I figure that out?) Thank you! Penny Nom lui répond. |
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The units digit of a square |
2021-09-04 |
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Aarzu pose la question : Sorry this may be a dumb question but how do you find possible unit digits of a
perfect square Penny Nom lui répond. |
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The diameter of an octagon |
2021-05-22 |
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Sue pose la question : What is the diameter of an octagon with 8 foot sides Penny Nom lui répond. |
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The height of a cone |
2021-05-13 |
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Carmen pose la question : If a cone has a slant height of 25 inches and a radius of 7 inches what is the
height in inches of the cone? Harley Weston lui répond. |
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More on a roll of paper |
2021-05-07 |
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Stephen pose la question : Can you help with the equations to calculate the length of paper required to
achieve a target outside diameter when wrapped around a core please?
The inside diameter of the cardboard core is 76mm
The thickness of the wall of the cardboard core is 5mm
The thickness of the paper is 138microns
The desired outside diameter of the finished roll is 320mm
I hope you can help me with a solution, Thank you Harley Weston lui répond. |
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The maximum area of a garden |
2021-04-28 |
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Lexie pose la question : suppose you want to make a rectangular garden with the perimeter of 24 meters.
What's the greatest the area could be and what are the dimensions? Penny Nom lui répond. |
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The volume of a spherical bowl |
2021-04-23 |
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Danny pose la question : How many gallons of water in a glass bowl with the dimensions of 10 inches high
and 13.5 inches wide? Penny Nom lui répond. |
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The distance between opposite vertices in an octagon |
2020-11-14 |
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joe pose la question : If the dimension from one flat part of an octagon to opposite flat is 500 mm what is the largest diameter (point to point) of the octagon? Harley Weston lui répond. |
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An analytic proof that a quadrilateral is a parallelogram |
2020-10-26 |
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Apollo pose la question : Prove analytically that if ABCD is a parallelogram in which points P and Q trisects the diagonal AC, then BPDQ is a parallelogram. Penny Nom lui répond. |
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A confusing problem |
2020-10-01 |
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Kgaugelo pose la question : a triangle has the vertices A(-4;-3),B(x;y)and C(2;1). Determine the coordinates of B if the equation of the line BC is y=5x-9 Harley Weston lui répond. |
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The height of a tree |
2020-09-27 |
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Kerissa pose la question : A man height 1.2 m standing on top of a building 34.6m high views a tree some distance away he observes that the angle of depression of the base of the tree is 35 and the angle of depression of the top of the tree is 29, assuming that the tree stands of level ground. Determine the height of the tree. Penny Nom lui répond. |
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my prcentage of years on earth is |
2020-09-21 |
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Bill pose la question : This Tuesday is my birthday and I will be 69. and I just wanted to know
life ear is say earth is 6 billion years old I'm just curious to what percentage does my existence on earth reptresent I do realize that it's a
flash in the pan Penny Nom lui répond. |
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The surface area of a dome |
2020-09-13 |
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Sue pose la question : i need to know the outside square footage of a dome house 24ft
across at the bottom and 16ft high so i know how much
paint it will take to cover it. Harley Weston lui répond. |
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The angular speed of a wheel |
2020-09-03 |
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Catrina pose la question : A car is moving at a rate of 75 miles per hour, and the diameter of its wheels is 2.6 in. Find the angular speed of the wheels in radians per minute. Penny Nom lui répond. |
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A diameter of a circle |
2020-08-19 |
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Apple pose la question : One end of the the diameter of the circle with equation x^2+y^2-4x+4y=2 is (3,1). Find the coordinates of the other end of the diameter. Penny Nom lui répond. |
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A tank, 5/9 full of water |
2020-07-28 |
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Nat pose la question : A rectangular tank contains 1200cmsquare of water when it is 5 out of 9 full . Its base area is 80cmsquare . Find the height of the tank. Penny Nom lui répond. |
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Percentage profit |
2020-05-30 |
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jaheem pose la question : A shopkeeper buys an article for 80cents and sold it for $1. Calculate the percentage profit. Penny Nom lui répond. |
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A triangular garden |
2020-05-24 |
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yoonji pose la question : the 3 sides of a triangular garden measure 200 ft., 250 ft., and 300 ft., respectively. the garden is to be divided by a line bisecting the longest side and drawn from the opposite vertex. what is the length of the bisecting line? Penny Nom lui répond. |
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Maximizing the volume of a cone |
2020-05-18 |
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Ella pose la question : Hello, this is question - 'If you take a circle with a radius of 42cm and cut a sector from it,
the remaining shape can be curled around to form a cone. Find the sector
angle that produces the maximum volume for the cone made from your circle.' Penny Nom lui répond. |
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An angle i a triangle |
2020-05-16 |
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Ogunjobi pose la question : Two goal post are 8m apart a footballer is 34 m from one post and 38m from the other within what angle must he kick the ball if he is to score Penny Nom lui répond. |
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Three numbers have a sum of 45 |
2020-05-06 |
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Jayden pose la question : Three numbers have a sum of 45. The greatest of the 3 numbers is 2 greater than the least number. What are the numbers? * Penny Nom lui répond. |
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The volume of a stone |
2020-05-02 |
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KHOSI pose la question : A rectangular container is 9cm wide,17cm long and contains water to a depth of 11cm. A stone is placed in the water and the water rises 2,2cm .Find the volume of the stone Penny Nom lui répond. |
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The volume under an an uneven surface |
2020-05-01 |
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Solon pose la question : I am trying to fill an area of floor which has an uneven surface. I need to know the volume of fill.
If you imagine a rectangular room (4 corners) that measures 189 inches by 240 inches and the depth at each corner is different.
Let us say corner #1 has a depth of 1", corner #2 has a depth of 0", corner #3 has a depth of 2" and corner #4 has a depth of 4".
How would i find the volume of said floor area?
Any assistance would be greatly appreciated! Harley Weston lui répond. |
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A system of equations. |
2020-04-27 |
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solomon pose la question : xy + x =28
x + y +4 Penny Nom lui répond. |
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The width of a rectangle of land |
2020-04-26 |
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Teresa pose la question : If a rectangle shape piece of land is 813 feet long. How many feet width would be 2 acres? Penny Nom lui répond. |
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Two chords |
2020-04-14 |
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Frank pose la question : How to find the length of the radius of a circle if you know the lengths of two chords Penny Nom lui répond. |
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A pond in a garden |
2020-04-09 |
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Jin pose la question : c) I have a large square pond set inside a square garden: both the pond and the
garden have sides which are a whole number of metres, and outside the pond,
the garden is grassed over. The area covered by grass is 188 square metres.
Find the area of the pond. (5 marks) Penny Nom lui répond. |
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The center and radius of a circle |
2020-03-25 |
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Riley pose la question : so it says find the center and the radius of the below circle
x^2+(y-6)^2=121
i need help learning how to solve this Penny Nom lui répond. |
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Is there an equation to find what percent of 0 is 1? |
2020-03-09 |
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Asher pose la question : Question: Is there an equation to find what percent of 0 is 1.
I remember learning quite a long time ago that the answer inst 0 and it isn't infinity. I'm pretty sure it was something like %=0 approaching infinity or %=1 approaching infinity. And I know it depends what value you assign the numbers i.e. dollars or temperature. Furthermore, is asking "what percent 1 dollar is of 0 dollars" the same question as "what percent profit do you make from selling something worth 0 dollars for 1 dollar."
Thank you for your time and consideration
-Asher Penny Nom lui répond. |
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The volume of a berm |
2020-02-28 |
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jason pose la question : how much dirt is in an 20'w 12't 1350'l berm Penny Nom lui répond. |
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A straight line graph |
2020-02-26 |
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Penehafo pose la question : I have a problem of drawing a straight line graph by the equation y=2x-1 Penny Nom lui répond. |
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The height of an isosceles triangle |
2020-02-23 |
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Reagan pose la question : I need to find the height of an isosceles triangle with a base of 6 and sides of 4 units. How do I find it? Penny Nom lui répond. |
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30% profit |
2020-02-20 |
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Sidra pose la question : A car dealer bought a car for £7500 and sold it for 30% profit.
For how much did he sell the car? Penny Nom lui répond. |
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Sipping juice from a Tetra Pak |
2020-02-11 |
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Anjhelic pose la question : Karen is sipping juice from a 1 in. by 3 in. by 6 in tetra pack at the rate of 0.5in³/sec. How fast is the height of juice in the pack decreasing? Harley Weston lui répond. |
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The area of a triangle from two angles and a side |
2020-02-10 |
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Chinmoy pose la question : How to measure the area of a triangle with two angles and length of the included side known? Harley Weston lui répond. |
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A system of inequalities |
2020-02-01 |
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Isaac pose la question : Austin has x nickels and y dimes, having a maximum of 15 coins worth a minimum of $1 combined. No more than 4 of the coins are nickels and no less than 11 of the coins are dimes. Solve this system of inequalities graphically and determine one possible solution. Penny Nom lui répond. |
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The volume of a coffee cup |
2020-01-25 |
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Amirah pose la question : What is the volume of a polystyrene cup with a height of 8cm, diameter of 5cm at the top and 4cm at the bottom when it is filled with water? Penny Nom lui répond. |
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The equation of a line |
2020-01-05 |
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coco pose la question : Good afternoon
If relationship between total cost and the number of units made it linear ,and if costs increases by 7$ for each additional unit made ,and if the total cost of 10 units is 180$ .
Find the equation of the relationship b/n total cost (Y) & number of unit made (x). Penny Nom lui répond. |
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Dividing the tips |
2020-01-02 |
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Pat pose la question : trying to figure out division of tips I have 3 full time employees 40 hrs a week and 1 part time worker 12 hours a week what percentages do i give them to give them appropriate tips :-) Harley Weston lui répond. |
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A circle, a point, and a tangent line |
2019-12-31 |
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Faisal pose la question : A circle has radius 10 units and passes through the point (5,-16). The x-axis is a tangent to the circle. Find the possible equations of circle? Penny Nom lui répond. |
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Volume of a tree |
2019-12-19 |
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Maria pose la question : I have trees for sale. I need to calculate the volume of a tree from base which is wider than the stem.The base will be used for the making of hurleys, similar to hockey sticks so the wider base is crucial. Penny Nom lui répond. |
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Odds |
2019-12-16 |
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Craig pose la question : I’d like to know what are the odds of a lotto machine giving out a specific 4 digit number as a quick pick?
I know there are 10,000 possible 4 digit combinations. So let’s say the number is 3587 what are the odds the lotto machine spits it out EXACTLY that way on a quick pick? Penny Nom lui répond. |
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The equation of a line |
2019-12-10 |
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Jourdan pose la question : Suppose a mining company will supply 96000 tons of ore per month if the price is 80 dollars per ton but will supply 70500 tons per month if the price is 20 dollars per ton. Assuming the supply function is of the form y = m x + b , find the slope, m and y-intercept, b Penny Nom lui répond. |
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Roll two dice and record the difference |
2019-12-09 |
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Barbara pose la question : Suppose you roll two dice 100 times. Each time you record their difference
(always subtracting the smaller one from the bigger one to get a positive
difference). The possible values you get are 0,1,2,3,4 and 5. You record
the frequency of each value in the following table:
Difference of two dice 0 1 2 3 4 5
Observed frequency 12 31 26 13 10 8
Let your null hypothesis be that the dice are fair, and the alternative
hypothesis be that they are not fair. Using a confidence level of α = 0.10,
test the null hypothesis by a goodness-of-fit test.
Hint: begin by
completing table:
x 0 1 2 3 4 5
f(x) Penny Nom lui répond. |
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The area and volume of a wedge |
2019-11-30 |
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Jasmine pose la question : what is the volume and surface area of a wedge with definition Penny Nom lui répond. |
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The product of 3 integers is -24 |
2019-11-06 |
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Rick pose la question : This is a question on my sons pre-ap practice quiz.
I think that there is information missing (?)
The product of 3 integers is -24
The sum of 3 integers is -12
What are the 3 integers ?
This is exactly how it was written on his quiz paper.
I have wasted to much time on the internet, trying to find a
formula(s) to help him.
Please help me. Penny Nom lui répond. |
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The sum of the ages of Ruth and her mother is 77 years. |
2019-11-06 |
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Lydia pose la question : The sum of the ages of Ruth and her mother is 77 years. The difference in their ages is 27 years. How old is each? Penny Nom lui répond. |
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Algebra |
2019-11-06 |
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Krizhia pose la question : How is y= 1/2 * (x-1)² be x= √2y + 1. Please show me the steps Penny Nom lui répond. |
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The divisors (aliquot parts) of a positive integer |
2019-10-31 |
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Kenneth pose la question : Is there a fast and simple method that can be used to determine the aliquot parts, whole, positive numbers that can divide into another whole, positive number? Harley Weston lui répond. |
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The center of a circle |
2019-10-24 |
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Patrick pose la question : I'm trying to find a quick calculation to find the center of the circle that will touch the 3 points of an isosceles triangle.
Known dimensions are length of the triangle base and the height from the top point to the middle of the base.
Thanks in advance,
Kind regards,
Patrick Penny Nom lui répond. |
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How many numbers from the set have the sum of its digits equal to 2? |
2019-10-24 |
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Marcel pose la question : Hello. My question is the following: Given the set {1,2...........10exp2019}, how many numbers from the set have the sum of its digits equal to 2?
I got some of them : 2 20 200 2000 20000 .......2. 10exp2018 11 110 1100 11000 110000....101 1010 10100 101000 1010000....10011 10010 100100 1001000 1010000.....10001 100010 1000100 10001000,,,,,,100001 1000010 10000100.......
My problem is that I have difficulty in finding a strategy to obtain the exact quantity of numbers. Please help me, thanks Penny Nom lui répond. |
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The perimeter of a piece of a circle |
2019-10-18 |
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Arwin pose la question : The radius of a circle is 17 cm. A chord XY lies 9 cm from the centre and divides the circle into two segments. Find the perimeter of the minor segment. Penny Nom lui répond. |
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The domain of f + g |
2019-10-16 |
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Angel pose la question : The domain of f+g when f(x)=8x+3 and g(x)=1-5x Penny Nom lui répond. |
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How do you find the length and the width if all you had was area? |
2019-10-16 |
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Ali pose la question : So, How do you find the length and the width if all you had was area? Penny Nom lui répond. |
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The volume of a fire hose |
2019-09-18 |
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Carlou pose la question : How many liters of water in a 2.5 inches diameter of fire hose with a 20 meters in length Penny Nom lui répond. |
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What is -5 squared? |
2019-09-10 |
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Pori pose la question : What is -5 squared? Penny Nom lui répond. |
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Vectors |
2019-09-06 |
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Kayla pose la question : Hi!
Due to time constraint issues, we skipped vectors in Pre-Calc last year. However, I'm attempting to complete my AP Physics summer homework and there are 3 problems with vectors. As I explained, I have no idea even where to begin and as such I need some help.
Problem 1:
A plane flying at 90° at 45 m/s is blown toward 0° at 62 m/s by a strong wind. Find the plane's resultant velocity.
I have tried all sorts of online calculators but none are providing me with a formula I can use to solve this problem on my own.
Problem 2:
If you walk 367 m North and 785 m West what is your total displacement from your original location?
What is the problem asking for when it says displacement?
Problem 3:
A plane travels on a heading of 127.0° at a velocity of 25 km/hr. What are the horizontal and vertical components of the plane's velocity?
As you know already, I have never done vectors so I don't know what horizontal and vertical components of velocity are.
Thank you So Much for your help!! I am struggling!!
- Kayla Penny Nom lui répond. |
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Using the Laws of Exponents |
2019-09-06 |
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Samiya pose la question : i have been struggling with the laws of exponents so im having trouble with this question. the
question is to write (b*exponent2*c)(b*exponent5*c*exponent4*) Penny Nom lui répond. |
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The volume of a berm |
2019-09-06 |
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John pose la question : I need to construct a berm:
8' tall
5' across the top
20' at the base
125' long
How much soil will I need Harley Weston lui répond. |
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Can one equation with two variables be solved algebraically? |
2019-08-30 |
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Don pose la question : Can one equation with two variables be solved algebraically? Penny Nom lui répond. |
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The length of half an acre |
2019-08-23 |
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Angeles pose la question : How many Feet Long In Half An Acre (Rectangle) Penny Nom lui répond. |
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The area of a shape |
2019-08-14 |
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Lymp pose la question : Hi, for math we are calculating the area of shapes and my teacher wanted me to research how to calculate the area of shapes so i was wondering if you could tell me how t calculate the area of any shapes. Please tell me how to calculate a cross, parallelogram and a polygon Penny Nom lui répond. |
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A cone of maximum volume |
2019-08-14 |
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Refilwe pose la question : The slant height of a cone is 10cm. Determine the radius of the base so that the volume of the cone is a maximum Penny Nom lui répond. |
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The radius of a circle of given area |
2019-08-14 |
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shelby pose la question : What's the radius of a circle that has an area of 803.84cm2? I also need examples of how you got the answer. Penny Nom lui répond. |
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The volume of a well |
2019-07-30 |
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Jordan pose la question : How much water could my well hold if the depth of the well is 30 feet
feet and the diameter of the well is 24 feet ? Penny Nom lui répond. |
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The maximum volume of a cone |
2019-07-14 |
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A student pose la question : find the maximum volume of a cone if the sum of it height and volume is 10 cm. Penny Nom lui répond. |
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Volume of a spherical cap |
2019-07-12 |
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Shanto pose la question : In a jar of water, we kept a sphere with radius r. Then 75% of its volume went under water. Find out the distance of the top of the sphere from the surface of the water. Penny Nom lui répond. |
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Order of operations |
2019-07-06 |
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Carri pose la question : What is the answer (( 5 × 12) / 3 ) + 30 - 50 Penny Nom lui répond. |
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The perimeter of 200 acres |
2019-06-14 |
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AARON pose la question : How many feet is the perimeter of 200 acres? Penny Nom lui répond. |
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How many lines of symmetry does a circle have? |
2019-05-28 |
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raji pose la question : how many lines of symmetry does a circle have??? Penny Nom lui répond. |
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The volume of a wall |
2019-05-08 |
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Peter pose la question : I’m building a dry stack stone wall which is 36” wide at the base, 42” tall and 24” wide at the top. What would be the volume for a 36” long segment ?
Thanks, Peter Penny Nom lui répond. |
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Volume and Surface area of a sphere |
2019-05-03 |
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Caitlin pose la question : Why does the surface area formula of a sphere have a squared radius while the volume of a sphere has a cubed radius? Penny Nom lui répond. |
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A dot on a child's car wheel |
2019-04-28 |
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julia pose la question : A wheel of a child’s car revolves at 10 rpm. A painted dot on the circumference of the wheel is 12 cm from the centre of rotation of the wheel. How far does the dot travel in 5 s, to one decimal place? Penny Nom lui répond. |
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The length of an arc |
2019-04-28 |
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Patrick pose la question : If an arch is 48 inches wide at the base and 30 inches tall at its apex, what is the length of the arch? Penny Nom lui répond. |
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Constructing a hexagonal pyramid |
2019-04-25 |
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REBECCA pose la question : I'm doing a project for my Honors Geometry class and I have to build a regular hexagonal pyramid. I was given the volume of .75 gallons, but I don't know how to figure everything else out. Please help?
Thanks,
Rebecca Harley Weston lui répond. |
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The area of a triangle |
2019-04-25 |
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troy pose la question : The base and the height of a right triangle are represented by the expressions below.
The area of the triangle is 28 square units. Find the lengths of the base and the height
of the triangle
base= x+4
height=x-6 Penny Nom lui répond. |
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The area of a lot |
2019-04-06 |
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Robert pose la question : Can you help me determine the rough square footage of this lot please(attached)? I think it is nearly 7000 square feet. I am sure I need the degrees of of the corners but I don’t have that. An estimate would be all I need.
Thank you for you help.
Rob Harley Weston lui répond. |
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The height of a building |
2019-04-05 |
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Hayley pose la question : A young man is 36 meters away from a building and looking at a bird sitting on top of the building. The man knows he is 85 meters away from the bird. How tall is the building? Penny Nom lui répond. |
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Internal acute angles |
2019-04-02 |
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karan pose la question : Prove that a convex polygon cannot have more than three acute internal
angles. Penny Nom lui répond. |
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The volume of a pile of dirt |
2019-04-01 |
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Genevieve pose la question : We have a pile of dirt approximately 6 feet high by 15 feet wide by 80 feet long.
We need to know how many cubic yards of dirt are in this pile. Thank you Harley Weston lui répond. |
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The volume of water in a pipe |
2019-03-21 |
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Abati pose la question : How can I calculate the volume of water in a pipe with below details;
Pipe diameter - 6 inches
Length of pipe - 127meters Penny Nom lui répond. |
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The area of a triangle |
2019-03-19 |
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Dylan pose la question : The area of a triangle is 108in squared. A base and corresponding height
are in the ratio 3:2. Find the length of the base and the corresponding
height Penny Nom lui répond. |
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Four consecutive positive integers |
2019-03-12 |
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Nabila pose la question : The product of four consecutive positive integers in 24024
What is their sum? Penny Nom lui répond. |
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A triangle of maximum area |
2019-03-07 |
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Tom pose la question : Triangle ABC is such that AB=3cm and AC=4cm.
What is the maximum possible area of triangle ABC? Penny Nom lui répond. |
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Misuse of greater than |
2019-03-07 |
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Kenneth pose la question : I have an old business mathematics textbook. The authors have indicated that the following expressions indicate multiplication:
? is 2/3 greater than 90; ? is 2/3 smaller than 90. They also indicated that the following expression would indicate division: 30 is 2/3 greater than ? and 30 is 2/3 smaller than ?.
How can these phrases indicate multiplication and division? How can 60 be 2/3 greater than 90 and also smaller than 90 as indicated above. What were the authors thinking? I have added the page from the book that indicates what I have explained in my message
Kenneth Harley Weston lui répond. |
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3 months loss and then a profit |
2019-03-02 |
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Ida pose la question : Let say, I have 10k of capital and I ran business for 4 months.
The first months i loss 50%, the second month i loss 50% and so do the third month.
The fourth month my profit is 50%
So can I calculate the balance of money that i have out of my capital? Penny Nom lui répond. |
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The top half of a cone |
2019-02-27 |
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danica pose la question : What portion of the height from top that the cone be cut into two equal volume? Penny Nom lui répond. |
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A quadratic equation problem |
2019-02-26 |
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Em pose la question : One root of the equation
2x^2 + bx - 24 = 0 is -8. What
are the possible values of b and
the other root? Penny Nom lui répond. |
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Composition of functions |
2019-02-24 |
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Joshua pose la question : Let g(x)=(x)^(2)+x-1
Find such a function f such that
(fog)(x)=(x)^(4)+2(x)^(3)-3(x)^(2)-4x+6 p lui répond. |
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The Polynomial Remainder Theorem |
2019-02-23 |
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pasandi pose la question : f(x) is a quadratic polynomial. when f(x) is divided by
(x-1),(x-2) & (x+2) the remainders respectively are -1, 4 and 2 how to find the f(x) in a question like this? Penny Nom lui répond. |
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Margin with commission as part of selling price |
2019-02-13 |
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Anni pose la question : I need to find selling price to put us at 24% margin.
15% commission is based on selling price and is included in our cost.
I'm trying to do it excel and keep getting a circular reference.
Total cost= cost + commission (15% of selling price)
Selling price=total cost + 24% margin Penny Nom lui répond. |
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A cylindrical drum |
2019-02-10 |
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Ronald pose la question : I have a cylinder that is 32 inches round by 25 inches deep how much water can it hold Penny Nom lui répond. |
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A fraction of a cent |
2019-02-01 |
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michael pose la question : $ 300 divided by 1,000,000 is 00.0003 ... so, is that three hundredths of one ($ 00.0003) cent or what ... thanks Penny Nom lui répond. |
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A median of a triangle |
2019-01-24 |
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Anna pose la question : For triangle J(1,4) K(-3,-1) L(3,4), find an equation for the median from vertex J Penny Nom lui répond. |
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A triangle made from 12 matchsticks |
2019-01-20 |
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Palesa pose la question : How many different types of triangles can be made with a perimeter of 12 matches? Penny Nom lui répond. |
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7 spheres on a hexagonal tray |
2019-01-14 |
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herm pose la question : what is the length of each side of a hexagonal tray, with the height of each side 0.75 inch, to hold seven spheres, each with a diameter of 3.00 inches? The spheres are placed such that each side of the hexagon is touched by one sphere at its midpoint (and the seventh sphere is place in the center of the "ring" of the other six spheres. Harley Weston lui répond. |
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The surface area of a dome |
2018-12-18 |
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Chithrabhanu pose la question : If a dom dia is 4.552 and the height is 1.21 what is the surface area? Penny Nom lui répond. |
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The area and weight of sod |
2018-12-11 |
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Susan pose la question : I have equipment that will cut sod 30 inches across and 75 Feet in length?
how much will this be in square foot age ? Yards? Approximate weight? Penny Nom lui répond. |
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A puzzling equation |
2018-12-04 |
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Manny pose la question : Hello,
Can you explain why this is wrong:
-1 = (-1)^3 = (-1)^{6/2} = ((-1)^6)^{1/2} = (1)^{1/2} = 1 ??
Thank you Penny Nom lui répond. |
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The price of eggs rises 10 cents per dozen |
2018-11-10 |
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Maddie pose la question : Hi! I'm currently struggling with a word problem that says:
"If the price of eggs rises 10 cents per dozen, one will be able to get 2 dozen fewer eggs with $6.00 than was possible at the lower price. What is the lower price?
We are working on completing the square and all of the problems I've done so far in this chapter require using that method. If possible and needed, could you explain how to set up the equation?
Thank you so much! I appreciate all your help!! Penny Nom lui répond. |
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Why 1/2 in the area of a circular sector? |
2018-10-26 |
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Ariel pose la question : In the equation for area of a sector=1/2r^2theta why is it 1/2? Please explain conceptually not algebraically. Penny Nom lui répond. |
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Why 1/3 in the volume of a cone? |
2018-10-20 |
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Keith pose la question : In the formula for the volume of a pyramid, Volume = 1/3 * base * height, where does the 1/3 come from, intuitively? Penny Nom lui répond. |
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The area of a trapezoid |
2018-09-24 |
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An other pose la question : AB-272 feet: AC 690 feet; CD-330 Feet; DA-669Feet Calculate the area in feet and Acres. Penny Nom lui répond. |
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Two curves |
2018-09-23 |
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Megan pose la question : How do i find the interception points of xy=-2 and y=x+3? Many thanks! Penny Nom lui répond. |
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The point-slope equation for a line |
2018-09-23 |
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Sally pose la question : The equation of the line in point-slope form for the line passing through the point ( 4, -6) and parallel to the line y = -6x + 2. Describe the steps. Penny Nom lui répond. |
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Predicting the number of fish in a lake |
2018-09-16 |
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April pose la question : A researcher catches 30 fish in a pond, attaches a marker to their fin and releases them. The next day she places a large net in the water and catches 9 fish. 3 have the marker attached to their fin. Can she predict the number of fish in the pond???
Thank you Penny Nom lui répond. |
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A locus of points |
2018-09-03 |
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Ericka pose la question : Find the locus of points three times as far from (0,4) as from (2,0) Penny Nom lui répond. |
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5 mm of water over 1 hectare |
2018-08-10 |
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Joyce pose la question : Please help me with this question.
How many tonnes of water fell on 1 hectare of land during a rainfall of 5mm? Penny Nom lui répond. |
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The surface area of a levee |
2018-07-04 |
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John pose la question : Figuring out the surface area in sq. Ft. Of a levee
Height:10’
Top of levee width: 6’
Width of base (from toe to toe): 40’
Length of levee: 1,250’ Penny Nom lui répond. |
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The product of two numbers |
2018-06-19 |
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amie pose la question : the product of two numbers is 108.when the larger number is divided by the smaller number the quotient is 3. What are the number.tnx Penny Nom lui répond. |
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The domain of f(g(x)) |
2018-06-18 |
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Joshua pose la question : What are the restrictions of the domain of f(g(x))? Penny Nom lui répond. |
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The number of terms in an arithmetic sequence |
2018-06-15 |
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Don pose la question : how many terms in arithmetic sequence are there if the first term and the last term are 3&59 respectively in common difference is 4? Harley Weston lui répond. |
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The area, radius and slant height of a cone |
2018-05-18 |
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joette pose la question : If you have a cone how to find the slant height when given the area and radius? Penny Nom lui répond. |
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Rods,poles and perches |
2018-05-13 |
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roy pose la question : i have some land and its measured in rods poles and perches
how cann i convert to understand it more Penny Nom lui répond. |
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Two expressions for the perimeter of a a rectangle |
2018-05-13 |
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Slayde pose la question : A rectangular house has one side 4 metres longer than the other. Create two different expressions for its perimeter. The expressions should be given in factorised and expanded form. Penny Nom lui répond. |
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Gauss' Addition of whole numbers. |
2018-04-30 |
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Brad pose la question : I found this on your site. Question: what is the sum of the first 100 whole numbers??
Is there a different formula if the numbers begin at a number other than one? For example
What is the series I want to add is goes from 7 - 53? Harley Weston lui répond. |
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Spreading soil over 10 acres |
2018-04-29 |
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Joe pose la question : If you have 54000 cubic yards of soil and want to spread it over 10 acres of land, by how many inches would the ground level rise? Penny Nom lui répond. |
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A rectangular prism with rounded corners |
2018-04-25 |
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Jackie pose la question : Rectangular prism that is 40 by 20 with rounded corners with a radius of 2.5.
What would the surface area be? Penny Nom lui répond. |
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More on the curvature of the Earth |
2018-04-23 |
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will pose la question : the formula for figuring the earth's curve goes against logic, looking at a fixed point and backup 1mi. the point drops 8" then 16" in the next mi. and 32" in the third mi. why shouldn't it be 24" why is the 8" per mi. squared can you tell me in laymens terms why this is it goes against logic it would seem the correct wat would be to add up 8" per mile as you back up from the fixed point 8"- 16"- 24"- 32" not 8/16/32/64" Harley Weston lui répond. |
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A volume expression for a pyramid |
2018-04-23 |
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Shaheer pose la question : Do a three sided pyramid and a square pyramid have the same formula if you want to calculate the volume? Penny Nom lui répond. |
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How to find the area of triangle? |
2018-04-19 |
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g.a pose la question : how to find the area of triangle Penny Nom lui répond. |
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The sides of a circle |
2018-04-10 |
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Reid pose la question : Hello,
I recently was wondering about whether or not a circle has an infinite number of sides, and I ended up searching it on your website. I saw that you guys found the question to be too ambiguous or something of that nature, and I thought about your process of reasoning involving vertices and such. I soon realized that I may have come up with the solution to the question, but I want to confirm it with you guys. Allow me to explain:
A circle, unlike any other typical 2 dimensional polygon, can sustain an infinite number of straight lines coming in contact with only one point on it. A square, for example, cannot. A square only has 4 locations that can sustain a such a line, each of those being its corners. The flat edge of a square cannot support a tangential line, because the line would either be crossing the edge of the square or coming into contact with multiple points along its edge.
This concept is consistent in every 2 dimensional polygon: pentagons sustain 5 locations for tangential lines, hexagons 6, nonagons 9, etc.
The reason a circle has an infinite number of sides is simply the fact that it must have an infinite number of "corners", assuming it can be defined as a polygon like any of the shapes I described above.
Corners can only exist assuming there is two sides coming into contact with one another.
If there is an infinite number of corners in the circle, which is apparent due to the above reasoning, there must be an infinite number of sides coming into contact with each other.
Thus, a circle is a polygon that consists of an infinite number of sides coming into contact with each other.
Please review this reasoning and let me know if it is solid.
Thank you! Penny Nom lui répond. |
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A circle problem |
2018-03-30 |
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ahamed pose la question : the diameters of a circle AB and CD intersect each other at O perpendicularly. Then a chord DF is drawn. AB and DF intersect at E. DE=6cn and EF=2cm.find the area of thw circle Penny Nom lui répond. |
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The volume of a tent with a hexagonal base |
2018-03-27 |
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shohel pose la question : A tent has its base in the shape of a regular hexagon whose sides are 10m . If the height of the tent is 12m , then find its volume. Penny Nom lui répond. |
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Distance between a chord and its arc on a circle |
2018-03-23 |
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Doug pose la question : Specifically, what is the subject distance for the Earth orbiting for 27 days. Assume the orbit of the Earth to be a circle have a 93 million mile radius. Assume the angle of arc to be (27/365) x 360 degrees. Thank you. Penny Nom lui répond. |
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Walking a fraction of a mile |
2018-03-20 |
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Jamie pose la question : Who walked a fraction of a mile that is closer to neither 0 nor 1 ? Explain
Avery 1/6
me.Nunez 5/6
Ms. Chang 1/3
Mr. O’Leary 4/8
Miss Lee 4/6 penny Nom lui répond. |
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The sum and difference of two numbers |
2018-03-13 |
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samima pose la question : Two numbers have a difference of 0.85 and the sum 1.What are the numbers? Penny Nom lui répond. |
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The dimensions of a rectangle |
2018-03-03 |
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Mia pose la question : A wire of length 36cm is bent to form a rectangle.
Find the dimensions of the rectangle. Penny Nom lui répond. |
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Expand (5x-9)(5x+9) |
2018-03-01 |
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adil pose la question : expand the following:
(5x-9)(5x+9) Penny Nom lui répond. |
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The perimeter of a square |
2018-02-25 |
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Alicia pose la question : What's the perimeter of a square with 441cm square Penny Nom lui répond. |
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Dividing a region in half |
2018-02-24 |
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mandy pose la question : There is a line through the origin that divides the region bounded by the parabola y=4x−5x2y=4x−5x2 and the x-axis into two regions with equal area. What is the slope of that line? Penny Nom lui répond. |
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The slope of a line |
2018-02-22 |
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Steve pose la question : my current slope is 6%. I want to know how many inches higher I will be at 18'
Thanks Penny Nom lui répond. |
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A footballer angle |
2018-02-14 |
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Kim pose la question : Two goal posts are 8m apart. A footballer is 34m from one post and 38m from the other. Within what angle must he kick the ball if he is to score a goal. Penny Nom lui répond. |
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Related rates |
2018-02-11 |
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angelo pose la question : hi admin please help me answer this question. thank you!
At a certain instant of time, the angle A of a triangle ABC is 60 degrees and increasing at the rate of 5degrees per second, the side AB is 10cm and increasing at the rate of 1cm per second, and side AC is 16cm and decreasing at the rate of 1/2 cm per second. Find the rate of change of side AB? Penny Nom lui répond. |
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Water in a cone |
2018-02-10 |
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Shuvo pose la question : The diagram shows a vertical cross-section of a container in the form
of an inverted cone of height 60 cm and base radius 20 cm. The circular
base is held horizontal and uppermost. Water is pursed into the
container at a constant rate of 40 cm3/s.
Show that, when the depth of water in the container is x cm, the
volume of the water in the container is (πx^3)/27 cm3.
Find the rate of increase of "x" at the instant when "x" = 2. Penny Nom lui répond. |
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Positive and negative values of a function |
2018-01-30 |
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Grayson pose la question : f(x)=x^6-x^4
Interval: ( negative infinity, negative one )
Test Value: negative two
Function Value f(x): positive forty eight
Interval: ( negative one, zero )
Test Value: negative one
Function Value f(x): zero
Interval: ( zero, positive one )
Test Value: positive one
Function Value f(x): zero
Interval: ( positive one, positive infinity )
Test Value: positive two
Function Value f(x): positive forty eight
What is the sign of f(x) for each Interval? Penny Nom lui répond. |
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The sum and difference of two numbers |
2018-01-25 |
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Ali pose la question :
Hello,
I was looking at the original question that was posted and answered by
your team:
http://mathcentral.uregina.ca/QQ/database/QQ.09.07/s/donna1.html
I used the 7 and 4 as example and not looking for 39 per original
question:
A=7
B=4
7+ 4 =11 and 7-4 = 3
We end up with 11 +3 = 14
A= 14/2 give use 7
B = how do you solve for B or 4 with out knowing anything about 3 or any other numbers ?
Thank you
Ali Penny Nom lui répond. |
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The equation of a line |
2018-01-23 |
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Gloria pose la question : Write the equation of a line in standard form through the point (1, 6) and perpendicular to the line 2x –y = 9. Penny Nom lui répond. |
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y as an expression in terms of x |
2018-01-20 |
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Mark pose la question : What is y as an expression in terms of x ? pennt lui répond. |
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Profit margin and markup |
2018-01-18 |
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Oyewumi pose la question : Mr A sold a car to Mr B at 20% profit margin and Mr B sold the car to Mr C at 30% markup on cost. If Mr C got the car at $x.
1. How much did Mr A buy the car in terms of x.
2. How much did Mr A buy the car if x is $2800000 Penny Nom lui répond. |
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When are the hands of a clock perpendicular? |
2018-01-11 |
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Nazrul pose la question : How many times in a day are the hands of a clock perpendicular to each other? How can I find the times? Please help me. Penny Nom lui répond. |
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A fraction of a mile |
2018-01-06 |
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Sierra pose la question : There are 5280 feet in a mile. what fraction of a mile is represented by 660 feet? Penny Nom lui répond. |
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A puzzling sequence |
2017-12-19 |
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Alan pose la question : My son has the following sequence to work out the formula for the nth term (and fing 5th and 6th terms) and I have tried a variety of ways but can't help!
1/2, 5/6, 1, 11/10
I have converted all to 15/30, 25/30, 30/30, 33/30 and so think the next two terms are 37/30 and 45/30 but I have no idea how to prove or if I am right!
Any help appreciated. Penny Nom lui répond. |
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Needing the area of an irregular Pentagon |
2017-12-06 |
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Dale pose la question : I'm needing to find the square footage of an irregular pentagon.
I've seen the other questions similar to this one, but without a great deal of difficulty can't get you the angle degrees, or the length between opposing angles.
I'm hoping that a different bit of information can help. So here goes:
The longest side is 67ft long.
One of its legs is 39ft long, and the other is 18ft long.
The leg off of the other end of the 39ft leg is 35ft long.
The leg off of the other end of the 18ft is 49ft long, and meets the other end of the 35ft side.
The information that I DO have, which I'm hoping makes the difference, is that the 39ft and the 18ft sides are parallel.
Also, while the angles at each end of the 67ft side are not right angles, they are fairly close to it,
approximately 80 degrees at the 39 ft side corner, and 100 degrees at the 18ft side corner.
Dale. Harley Weston lui répond. |
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Heat equation |
2017-11-23 |
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Max pose la question : What does du\dt=a(triangle)^2u mean. Can it be solved for t. Penny Nom lui répond. |
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How many miles did he drive in one hour? |
2017-11-21 |
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Ava pose la question : Graham drove 42 1/3 Miles in 1 1/3 hours. How many miles did he drive in one hour? Penny Nom lui répond. |
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An expression for the area of a triangle |
2017-11-19 |
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hari pose la question : why is area of a triangle drawn from centre of a circle i.e radii forming the sides is
1/2 *r^2 sin theta where r is radius Penny Nom lui répond. |
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Splitting twice |
2017-11-11 |
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Terry pose la question : 4 people are splitting 1/3 of something. 1 is to receive twice as much as the other 3. what it the fractional interest for each? Penny Nom lui répond. |
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The graph of graph y= -2x-1 |
2017-11-11 |
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Natividad pose la question : How do you graph y= -2x-1? Penny Nom lui répond. |
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Surface area of a hemisphere |
2017-10-28 |
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Shaina pose la question : If the total surface area of a hemisphere be 36.22/7 cm then its radius will be 3 cm is it true or false Penny Nom lui répond. |
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f(x)=-x^2-6x find f(x-2) |
2017-10-27 |
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Kenneth pose la question : f(x)=-x^2-6x find f(x-2) Penny Nom lui répond. |
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The distance between the origin and a moving point on a graph |
2017-10-16 |
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Paulina pose la question : Find the rate of change of the distance between the origin and a moving point on the graph of y=x^2 +1 if dx/dt=2 centimeters per second Penny Nom lui répond. |
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The volume of a cone without calculus |
2017-10-02 |
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Akash pose la question : How to find the volume of a cone without the knowledge of calculus? Penny Nom lui répond. |
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The square root of 6 is irrational |
2017-10-02 |
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John pose la question : http://mathcentral.uregina.ca/QQ/database/QQ.09.06/sylvia1.html
In the initial assumption of that proof, root 6 is assumed to be a/b where a and b have no common factors, but why does having a common factor make it irrational? Penny Nom lui répond. |
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Four multiples of 10 |
2017-09-23 |
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Laudacir pose la question : Four multiples of 10 are added together.the total is a 3 digit number with three consecutive digits. What could the four number be? Penny Nom lui répond. |
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The surface area of a sphere |
2017-09-17 |
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penny pose la question : The surface area of a sphere is 1519.76cm. Taking 3.14 , find the radius of sphere Penny Nom lui répond. |
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Quadrilateral ABCD is inscribed in a circle |
2017-09-11 |
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Joie pose la question : Quadrilateral ABCD is inscribed in a circle such that side DA is the diameter. AB=2m., BC=4m., CD=6m., angle BAD=75.93degrees. Find the area of the quadrilateral. Penny Nom lui répond. |
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The volume of an attic |
2017-09-07 |
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paul pose la question : trying to determine volume of an attic base is rectangular 29 ft by 37 ft
peak runs parallel to longest base side and is 7 ft long
roof lines run from each end of the peak to the respective corners
the peak is 3.5 ft above the base
(so seen from above there are 5 visible lines: the peak and 1 line to each of the 4 corners) Harley lui répond. |
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The perimeter of a sector of a circle |
2017-08-11 |
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Alisa pose la question : find the perimeter of the sector with radius 7 cm in which the angle at the centre is 60 degrees leave your answer in terms of pi Penny Nom lui répond. |
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Teams of 4 from 20 people |
2017-08-04 |
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Christopher pose la question : math team has 20 people on the team but only 4 can enter the competition. The team captain has to pick 4 of them but he knows that he cannot put James, Bill or Todd on the team with one another or there will be problems. what would the formula be to find the solution to how many possible team combinations the are Penny Nom lui répond. |
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3 consecutive multiples of 11 |
2017-07-22 |
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nisha pose la question : using the multiples formula shown at ypur site how can we solve finding 3 consecutive multiples of 11 whose sum is 363 Penny Nom lui répond. |
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The equation of a circle |
2017-07-03 |
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Chen pose la question : Find the center radius and equation of a circle in standard form given the following conditions:
1. Tangent to 3x+2y=0 at the point (0,0) and passing through (1,-1) and (6,0) Penny Nom lui répond. |
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The surface area of a hexagonal pyramid |
2017-06-16 |
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Emilie pose la question : Hello, I need help with this question:
A pyramid has a regular hexagonal base with side lengths of 4 and a slant height of 6. Find the total area of the pyramid.
Thank you in advance if you can help me... Penny Nom lui répond. |
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The maximum area of a rectangle with a given perimeter |
2017-06-02 |
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Bob pose la question : How would I go about finding the maximum area of a rectangle given its perimeter (20m, for example)? Penny Nom lui répond. |
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Two wires between two buildings |
2017-05-11 |
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Bill pose la question : I need to find the height of the intersection point of two building wires< br />
Building A is 860 feet high and building B is 480 feet high. The wires existent from the top of one building to
The bottom of the other < br />
The distance between is 32 feet Penny Nom lui répond. |
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Canada's population as a percentage |
2017-05-11 |
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bethmarie pose la question : What percentage of the world population (7.5 billion) is Canada's population (36 million).
Thank you very much! Penny Nom lui répond. |
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Slicing an inverted bowl at various heights |
2017-04-30 |
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Joel pose la question : Find a formula to calculate the circumferences of an inverted bowl at various heights.
E.g. Take an inverted bowl with a diameter of "x" cm and a depth / height of "y" cm.
How can I calculate the circumferences at distances of various heights above the base?
Alternately, what would be the formula to calculate the distance of the line segment resulting from a line which intersects both sides of a parabola in which that line is drawn parallel to the tangent of the vertex of the parabola at any given distance from the vertex? Penny Nom lui répond. |
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1 acre as a 2 foot wide strip of land |
2017-04-25 |
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alan pose la question : How can one convert 2 acres (a square - area) of land into a strip of land that is 2 feet wide and (?) feet long? Penny Nom lui répond. |
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The length of a train |
2017-04-24 |
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Stefano pose la question : If a freight train is coming towards you and you were traveling at 85 miles an hour and it takes 35 seconds for the train to pass you how long is the train
Figure 50mph for train Penny Nom lui répond. |
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Forming a cone from a circle |
2017-04-15 |
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Tasha pose la question : A sector of a circle subtends an angle of 216 degrees at the centre, If this sector is used to form a cone of vertical height ,8cm, calculate the base radius of the cone Penny Nom lui répond. |
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Why does 10x10x10 give 1,000.0000000000001? |
2017-04-12 |
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Randolph pose la question : Hi, On your calculator I found that a box 10 by 10 by 10 inches has a volume of 1,000.0000000000001 cubic inches. Can you explain the numeral 1 thirteen places past the decimal? Thanks, Randy Penny Nom lui répond. |
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The height of a isosceles trapezoid |
2017-04-03 |
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Riham pose la question : Hi
How can I find the height in an isosceles trapezoid if I have the measurements of all of its sides ?
Thank u in advance. Penny Nom lui répond. |
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The sum and difference of two numbers |
2017-03-20 |
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Olivia pose la question : The sum of two numbers is 87 and their difference is 29. What are the two numbers Penny Nom lui répond. |
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2^a, 2^b, 1^1 and 1^0 |
2017-03-17 |
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Émile pose la question : If you had 2^a = 4 and 2^b = 4 you could assume that a = b right? Yet we can observe that 1^1 and 1^0 both equal 1, yet 1 = 0 isn't true. So if given a log base 1 number 1 the would the answer be 1 AND 0? Penny Nom lui répond. |
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The ratio of two ages |
2017-03-15 |
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Angel pose la question : The sum of Keith's age and Alan's age is 36. Four years ago, the ratio of Keith's age to Alan's age was 4:3. Find the ratio of their present age Penny Nom lui répond. |
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What is the grade of the incline? |
2017-03-12 |
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Jon pose la question : If I am climbing 16 feet in elevation over 80 feet horizontal. What is the grade of the incline Penny Nom lui répond. |
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More on calculating the area (acreage) of a four-sided lot |
2017-03-06 |
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Kerri pose la question :
Can you please show the formula used to calculate areas as provided on this page:
Calculating the area (acreage) of a four-sided lot Penny Nom lui répond. |
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The inside diameter of a silo |
2017-02-28 |
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JOHN pose la question : I need to find the inside diameter of a cement silo with an outside circumference
118 ft and a wall thickness of 7 inches. thank you John Kerr. Penny Nom lui répond. |
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The volume of a slab |
2017-01-21 |
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Russell pose la question : Working with a segment of a circle. The O.D. is 3.440" the length of the chord is 3.130 I need information on the volume of the largest area. I would like to know (in thousands of an inch) how tall would the largest area need to be to equal .1143 cubic inches If you need more info I can send it Thanks in advance p lui répond. |
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The average rate of change of cot(t) |
2017-01-18 |
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Brianna pose la question : Hello!
It's been a while since I've taken a math course, and I'm stuck on a problem in my calculus course.
The question is this:
Find the average rate of change of the function over the given interval.
h(t)=cot(t) a) [5pi/4, 7pi/4] Penny Nom lui répond. |
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One millionth of one percent of 90,000,000,000 |
2017-01-16 |
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Gene pose la question : What absolute number is one millionth of one percent of 90,000,000,000 Penny Nom lui répond. |
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8^3/2(2+2) |
2017-01-13 |
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Mary pose la question : 8^3/2(2+2) Penny Nom lui répond. |
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Water leaking from a trough |
2016-12-28 |
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Kathryn pose la question : A trough is 6 m long, and has uniform cross-section of an equilateral triangle with sides 1 m.
Water leaks from the bottom of the trough, at a constant rate of 0.1 m3/min.
Find the rate at which the water level is falling when the water is 0.2m deep. Penny Nom lui répond. |
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20+30*0+1=? |
2016-12-26 |
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Mr pose la question : 20+30*0+1=? Penny Nom lui répond. |
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Two concentric circles |
2016-12-21 |
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shrestha pose la question : Two concentric circles have radii of 14 cm and 7 cm respectively. Find the area of space between them. Penny Nom lui répond. |
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The inverse of y=x^2+x+c |
2016-12-21 |
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Sam pose la question : What is the inverse of y=x^2+x+c for x? Penny Nom lui répond. |
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The inverse of y = x(x - 2) |
2016-12-21 |
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Sasha pose la question : Hello, I recently stumbled upon this question and I haven't been able to figure it out.
Why is the inverse of y=x(x-2) not a function?
Suggest a domain restriction which would ensure that the inverse is a function.
Thank You :) Penny Nom lui répond. |
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The area and radius of a circle |
2016-12-19 |
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india pose la question : How do you find the radius of a circle if only the area is given to you? Penny Nom lui répond. |
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980 cubic yards of dirt |
2016-12-17 |
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Jondi pose la question : I am trying to visualize 980 cubic yards of dirt by using a metaphor.
Would this be the size of a car?
A fire engine?
A semi-trailer?
How many trucks would you need to haul away 980 yards of dirt? Penny Nom lui répond. |
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1/1-cosine(2x) - 1/1+ cos(2x) |
2016-12-14 |
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Sean pose la question : 1/1-cosine(2x) - 1/1+ cos(2x) Penny Nom lui répond. |
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How far apart are the boats? |
2016-12-13 |
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Halley pose la question : Two boats leave port at the same time. Boat A travels east at a speed of 12 km/hr. Boat B travels southwest at a speed of 14 km/hr. After two hours, how far apart are the boats? North is 0 degrees. How do I figure this out.
Thanks Penny Nom lui répond. |
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Profit and loss on two shirts |
2016-12-06 |
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Mahesh pose la question : A man purchases one shirt and one T-Shirt for Rs. 6000. He sells the shirt at a profit of 20% and T-Shirt at a loss of 10%, as a result he gains 2% on whole transaction. what is the cost price of the T-Shirt ? Penny Nom lui répond. |
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Gallons and cubic inches |
2016-12-05 |
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Theresa pose la question : If I did not know the cubic inches in a liquid gallon how would I find it?
In other words what is the formula for this? Penny Nom lui répond. |
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The amount of material remaining on a roll |
2016-11-11 |
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Yoh pose la question :
Question from Yoh:
Hello,
I am trying to find impressions on a roll (either full roll or partial).
Let's say I have the following information.
- Outer Diameter of roll
- Inner Diameter of roll (cardboard core)
- thickness per layer
- Each cut off length (impression length)
Now let's say a roll has a 40in outer diameter, the cardboard core has a 3.75in diameter and a thickness of .002. Each impression has a cut off of 14inches.
With this the roll will have approximately 2,700 impressions. How would I find the remaining impressions if the outer diameter of the roll is only 6.5inches?
Thank you. Penny Nom lui répond. |
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The derivative of the inverse of a function |
2016-10-28 |
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Kate pose la question : Hi, I'm in a College level Calculus course and I can't seem to figure out the answer to this question.
Find the derivative of f^-1(4) if f(3)=4 and f'(3)=1/7 Penny Nom lui répond. |
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y = mx + c and Ax + By + C = 0 |
2016-10-18 |
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Erick pose la question : please explain to me how to convert an equation from the form y=mx+c to Ax+By+C=o form. Penny Nom lui répond. |
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The degree of 2x + 7 |
2016-10-17 |
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Deejay pose la question : How about when the given has no degree and the other has a constant only, For example 2x + 7,
where's the leading term and what is its leading coefficient? Penny Nom lui répond. |
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The equation of a line |
2016-10-01 |
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Miriam pose la question : write the equation of the line that passes through (6,7) and is perpendicular to 3x+5y=0 Penny Nom lui répond. |
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The equation of a circle |
2016-09-30 |
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Trent pose la question : write the equation of circle B with center B(-2,3) that passes through (1,2) Penny Nom lui répond. |
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Two equations |
2016-09-17 |
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Nilesh pose la question : How to solve (x-y)^1/2 + 3(x-y) = 30 ; xy + 3(x-y) = 11? Penny Nom lui répond. |
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The radius of a coffee cup |
2016-09-12 |
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Brett pose la question : What is inside radius, in centimeters of a coffee cup if it holds 350g of coffee when filled to a depth of 9.5 cm? Assume coffee has the same density of water, 1.00g/cm3. A numeric value is expected and not an expression. Penny Nom lui répond. |
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The equation of a ski slope |
2016-08-31 |
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Hannah pose la question : The information provided is
---A ski slope has a slope of -0.2. You start at an altitude of 10,000ft.
Then the question is "Write the equation giving altitude (a) as a function of horizontal distance moved (d).
I know this is probably a very simple question but I didn't take a math class my senior year and now I'm a freshman in college, so some of it is very frustrating to me.
Any help is much appreciated, thank you! Penny Nom lui répond. |
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The dimensions of a rectangle |
2016-08-31 |
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Hazym pose la question : How do I find the length(which is 15m longer than the breadth) and the breadth of a rectangle just by its perimeter which is 70 m? Penny Nom lui répond. |
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Covering an octagonal region with sand |
2016-08-13 |
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Lynn pose la question : How much sand is needed to fill a 20 ft. wide octagon area 6 inches deep? Penny Nom lui répond. |
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The area of a circle |
2016-08-12 |
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sandeep pose la question : if circumference of a circle is πd what is the area? Penny Nom lui répond. |
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The diameter of a cylindrical tin |
2016-08-04 |
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Scott pose la question : a cylindrical tin is 15 inches high and holds 5 gallons of paint when it is full. Find the diameter of the tin.
(1 gallon = 0.1605 cubic feet) Penny Nom lui répond. |
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The dimensions of a rectangle |
2016-07-25 |
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Krunox pose la question : A rectangle is twice as long as it is wide. Its perimeter (the sum of the lengths of its sides) is 60 cm. Find its length and width. Penny Nom lui répond. |
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The number of sides of a polygon |
2016-07-23 |
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Shriya pose la question : All the angles of a polygon are either 155° or 140°.
There are twice as many angles of 155 °or 140°.
Find the number of sides of the polygon Penny Nom lui répond. |
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A congruence theorem for two right angled triangles |
2016-07-17 |
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Sayari pose la question : Hello.
Is it possible for two right angled triangles to have the same length of base and height and a different hypotenuse? If not so, then why in the congruence criteria RHS the hypotenuse is given more importance? It can also be like- 'two triangles are congruent if they are right angled and have the same base and height.'
Thank You. Penny Nom lui répond. |
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The composition of a function with itself |
2016-07-17 |
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Mel pose la question : If f(1 + 3x) = 1 * x, solve f(f(x)) Penny Nom lui répond. |
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Triakis |
2016-06-27 |
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Gordon pose la question : Some authorities treat "triakis" (and related terms "dyakis", "tetrakis", etc.) as attached prefixes; others treat them as separate adjectives. Thus I see one of the Catalan solids described as both "triakistetrahedron" and "triakis tetrahedron". Which usage is correct? Chris Fisher lui répond. |
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Subsets |
2016-06-26 |
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Kats pose la question : How Many sub sets are in set k={6,7,3} Penny Nom lui répond. |
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Cubic feet of soil |
2016-06-19 |
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H pose la question : A garden is 8 ft x 7 ft that needs to raised 6 inch's How many cubic feet of soil required ? What am I missing ?
Thanks
H Penny Nom lui répond. |
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Profit |
2016-06-15 |
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Toyia pose la question : 12.87 profit from 21.99 sale. What is the percentage that was taken off the 21.99 Penny Nom lui répond. |
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A barn roof |
2016-05-29 |
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Joe pose la question : Is it possible to build a barn roof (irregular pentagon?) with a 12' base and the other 4 sides 4' each? Thanks. Penny Nom lui répond. |
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A cylinder in a cube |
2016-05-25 |
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Sonia pose la question : A cylinder has the same height and diameter as the sides of a cube use 3.14~ which has the greater volume Penny Nom lui répond. |
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The area of a 4-sided lot |
2016-05-25 |
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prasad pose la question : How to find area of a land whose sides are 41ft,33ft,32.3ft and 33.2 ft. Pl give me the formula and proof. Penny Nom lui répond. |
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Two pieces of rope |
2016-05-21 |
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Render pose la question : Fred cuts a 12- inch piece of rope. Then he cuts a second piece of rope that is 3/2 longer than the first piece. Is the second piece shorter or longer than the first piece? Explain. Penny Nom lui répond. |
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A trough with a triangular cross section |
2016-05-21 |
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Clarice pose la question : A trough having an equilateral triangle end sections has sides equal to 0.4 m and 7m long.what is the volume of the liquid in the container if the depth of the water is one half the depth of the trough? Penny Nom lui répond. |
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The volume of a truncated rectangular pyramidal pond |
2016-05-13 |
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Paul pose la question : How do you calculate a partially filled truncated rectangular pyramid if you always know the bottom rectangle, the maximum height top rectangle perimeter, but have a varying height. Similar to filling up a pond you know the current height and dimensions at the max rectangle how do you calculate it half full i.e. 10x30 outside perimeter with a 2x8 base and a max height of 6ft how do you calculate it at 3ft without re-measuring the top perimeter.
Thanks,
Paul Harley Weston lui répond. |
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A pair of equations with fractions |
2016-05-11 |
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tiya pose la question : hello, i want to know how to solve this question.
m/6+2n/3=6
-m/10=2n/5=2 Penny Nom lui répond. |
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Solve 2^2x + 3(2^x) - 4 = 0 |
2016-04-27 |
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Lloyd pose la question : Solve the equation 2^2x + 3(2^x) - 4 = 0 Penny Nom lui répond. |
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The inverse function for f(x)=2x^2+5x |
2016-04-23 |
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Ashini pose la question : The inverse function for f(x)=2x^2+5x Penny Nom lui répond. |
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A sector of a circle |
2016-04-21 |
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mustafa pose la question : In a sector of a circle, the arc length is equal to half the perimeter of a sector.find the area of a sector in terms of r Penny Nom lui répond. |
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15.86 acres |
2016-04-21 |
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Ronald pose la question : If a rectangular piece of land is 1320 ft. on one side, how many feet would be required on the other side to equal 15.86 acres? Penny Nom lui répond. |
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A square of side length 4x-3 units |
2016-04-20 |
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Bryan pose la question : Find an expression that represents the area of a square with side length 4x-3 Penny Nom lui répond. |
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The derivative of x! |
2016-04-16 |
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Sang pose la question : How to find the derivative of x! and integral of x! Penny Nom lui répond. |
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tan15° |
2016-04-11 |
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JOHN pose la question : find the exact value of tan15° in surd form. Penny Nom lui répond. |
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Filling a hole with 14 tons of rock |
2016-04-08 |
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Barry pose la question : If I had 14 tons of inch and one half sized aggregate rock, how large of a square or rectangular shaped hole would I need to hold that amount? Penny Nom lui répond. |
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The last two digits of a phone number |
2016-04-03 |
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Joshua pose la question : I want to find the last two digits of a phone number whose first eight numbers of a ten digit phone numbers are known. Penny Nom lui répond. |
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The volume of a cone |
2016-03-31 |
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Odum pose la question : Find the volume of a cone with radius 6.5cm and height 12.6cm Penny Nom lui répond. |
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The volume of a box with a hexagonal base |
2016-03-27 |
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Frank pose la question : how many gallons of water in an 8" hexagon shaped box. 6" sides x 12.5" high ? The walls are 1" thick , beveled @ 30 degrees, so inside dimensions are 6" Penny Nom lui répond. |
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Travelling in a spacecraft |
2016-03-25 |
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julie pose la question : if i was travelling in a spacecraft at the speed of light and i turned on my headlight would i see the beam ? Robert Dawson lui répond. |
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A rotating schedule for a softball team |
2016-03-25 |
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Caroline pose la question : I couldn't find a similar question, hopefully there isn't one!
I have a softball team of 18 people (7 girls and 11 boys), but am limiting each game to 13 players (6 girls and 7 boys). The season is 10 games long. How do I create a rotating schedule which allows members to play evenly? I tried separating the boys and girls to create rotation for each but I got confused. Some are unable to attend all games but for the simplicity of a rotation schedule can you please help? Robert Dawson and Victoria West lui répond. |
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The inverse of a function |
2016-03-20 |
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Billy pose la question : f(x) = Square root(x^2 + 2x)
What is the inverse? Penny Nom lui répond. |
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The perimeter of a rectangle |
2016-03-17 |
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Linda pose la question : Noel correctly adds the length of three sides of a rectangle and gets 88 cm her brother Ryan correctly adds the lengths of three sides of the same rectangle and gets 80cm. What is the number of cm in the perimeter of the rectangle Penny Nom lui répond. |
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A block wall |
2016-03-15 |
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Robert pose la question : I have a wall 40 ft. long and 4 ft. tall as well as another one that is 30 ft by 3.5 ft. tall that I am trying to build. how many 6 inch by 12 inch landscaping blocks do I need? Penny Nom lui répond. |
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The sides of a triangle |
2016-03-15 |
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Hitarth pose la question : Why we cannot construct a triangle ofngiven sides 5cm,5cm and 10cm? Penny Nom lui répond. |
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Angles |
2016-03-12 |
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Laurynn pose la question : What are angles in general (please include the 'angle of incline')
Thank you
Laurynn Penny Nom lui répond. |
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The integral of a sum |
2016-03-10 |
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Rahul pose la question : How to solve definite integral of a sum. The specific problem is as follows,
Integral of ( 1+ sum of x^k, k=1 to k=n), x=0 to x=b *dx.
The answer is b + sum of b^(k)/k, k=2, to k=n+1. I understand only the integral
of first term. But integral of the sum I do not understand at all. Penny Nom lui répond. |
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The area of a rectangle |
2016-03-03 |
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Lucas pose la question : The area of a rectangle is given by A=x2+18x+72
-use factoring to find an expression for the dimensions of the rectangle.
-if the area of the rectangle is 7 square feet, what are the possible values of x?
-what are the dimensions of a rectangle? Penny Nom lui répond. |
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Corrosion inhibitor in a pipeline |
2016-03-02 |
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Edu pose la question : I have a 12 in pipeline and 5 miles long. I need to coat it with corrosion inhibitor how much chemical will I need Penny Nom lui répond. |
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A rectangular prism |
2016-03-02 |
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Paula pose la question : Trying to help with a math problem. I don't know how to set up the equation for this.
A rectangular prism has a volume of 7.875m3rd and a height of 3.5 m. What is the area of the base of the prism?
Thanks for your help! Penny Nom lui répond. |
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An algebra problem with a sphere |
2016-02-29 |
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Sania pose la question : If the number of square centimeters on the surface area of a sphere is equal to the number of cubic centimeters in its volume find its diameter Penny Nom lui répond. |
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10800 sq. ft equal approx what part of an acre? |
2016-02-27 |
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David pose la question : 10800 sq. ft equal approx what part of an acre Penny Nom lui répond. |
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The sum of the angles of a triangle |
2016-02-24 |
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Sophia pose la question : Does every triangle add up to 180 degrees? (Such as a unique triangle) Penny Nom lui répond. |
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The weight of some dirt |
2016-02-24 |
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Michael pose la question : How many tons of dirt are in a triangle 14M x10M x 8.1M x .8M deep? Penny Nom lui répond. |
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The domain and range of a function |
2016-02-19 |
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Genius pose la question : State the domain and range
g(x)=x(x-1) Penny Nom lui répond. |
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The interior and external angles of a regular polygon |
2016-02-17 |
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percy pose la question : a regular polygon has n sides .The size of each interior angle is eight times the size of each exterior angle .
1.find the size of each exterior angle
2.calculate the value of n Penny Nom lui répond. |
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The equation of a vertical line |
2016-02-07 |
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Kagiso pose la question : The equation for a vertical line that goes through the point (7; -3) is? Penny Nom lui répond. |
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The midpoints of the sides of a quadrilateral |
2016-02-05 |
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Andrea pose la question : The segments, joining, in order the midpoints of consecutive sides of a quadrilateral form a parallelogram. Penny Nom lui répond. |
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The height of a triangle |
2016-02-03 |
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Brooklyn pose la question : How do I figure out the height of a triangle when it only tells me the base of he triangle? And vice versa. Penny Nom lui répond. |
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The diagonals of a polygon |
2016-01-29 |
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Sofia pose la question : What are diagonals and if you drew an octagon and drew all the diagonals how many would there be? Please explain because this is pretty confusing! Thank you! Harley Weston lui répond. |
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Consecutive angles of a parallelogram |
2016-01-28 |
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Hanna pose la question : The consecutive angles of a parallelogram measures Penny Nom lui répond. |
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The range of a function with a finite domain |
2016-01-25 |
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Hannah pose la question : Solve y=(1⁄4)x-1 if the domain is (-4,-2,0,2,4).
I don't get how to do this. Can anyone help? Penny Nom lui répond. |
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A system of linear equations |
2016-01-24 |
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kareem pose la question : my name is kareem
and i am a student i have a math puzzle and i tried to solved it but it always have same mistake
x-y=9
x+z=12
z-n=14
y+n=2 Penny Nom lui répond. |
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Fractions of two quantities |
2016-01-22 |
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Melody pose la question : Kate ate 1/4 of her orange. Ben ate 2/4 of his banana. Did Kate and Ben eat 3/4 of theit fruit? Explain. Penny Nom lui répond. |
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The perimeter of a square |
2016-01-16 |
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dennis pose la question : If I have eleven Square Acres, what would the perimeter dimensions be? Penny Nom lui répond. |
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A limit of a rational function |
2016-01-16 |
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selvamani pose la question : F (x) = x^3+3x^2-9x-2 / x^3-x-6 and limit x tends to 2, f (x) exist then limit x tends to 2, f (x) is equal to ? How to answer this problem. Penny Nom lui répond. |
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Complex numbers in standard form |
2016-01-15 |
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Michael pose la question : express the following complex numbers in standard form (2+3i)+(5-2i) Penny Nom lui répond. |
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The range of a function defined piecewise |
2016-01-13 |
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sarah pose la question :
f(x)={x-2, x<-2
{x^2-4, -2_<x_<2
{x+2, x>2
find the range Penny Nom lui répond. |
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The perimeter of a triangular plot of land |
2016-01-11 |
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Janelle pose la question : I need to fence off 6.5 acres. The plot is triangular shape. How many feet would I be fencing off? Penny Nom lui répond. |
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The area of a rectangle |
2016-01-08 |
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ranjan pose la question : if we make a rectangle with a 100cm of wire, then its area will be? Penny Nom lui répond. |
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Two transport companies |
2016-01-06 |
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Brynleigh pose la question : The Sugar Sweet Company will choose from two companies to transport its sugar
to market. The first company charges $5096 to rent trucks plus an additional fee of
$200.75 for each ton of sugar. The second company charges $5500
to rent trucks plus an additional fee of $175.50 for each ton of sugar.
For what amount of sugar do the two companies charge the same?
What is the cost when the two companies charge the same? Penny Nom lui répond. |
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A graph of the water level of a river |
2016-01-05 |
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emoni pose la question : Suppose that the water level of a river is 34 feet and that it is receding at a rate of 0.5 foot per day. Penny Nom lui répond. |
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The height of a parabolic arc |
2015-12-30 |
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Tom pose la question : Is there an algebraic means to determine the highest point of a parabolic arc if the base and perimeter are known? Penny Nom lui répond. |
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Strings of characters |
2015-12-28 |
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Ali pose la question : If I have an app and offer a two, three and four digits name and it can be only number, letters or both?
I want to know how many options will I have for each?
For example
the two digits: aa, 11, a1 or 1a
the three digits: 111, a2a, 222
the four digits: 1111, 2ge3 or 1234
So if I used all the letters and all the numbers but nothing starts with a zero
How can I calculate them separately? Or what's the result for each?
Thank you
Ali Penny Nom lui répond. |
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A diameter of a circle |
2015-12-27 |
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sahil pose la question : Find the equation of diameter of circle x2 +y2-6x +2y-8 which passes through the origin. Penny Nom lui répond. |
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The angles of a triangle |
2015-12-17 |
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Faith pose la question : Does the measure of angle determine the length of its side? For example two angles are congruent then the sides are also congruent because from my understanding the angle determine the shape of triangle. Penny Nom lui répond. |
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Proof that an erroneous algebraic statement is false |
2015-12-14 |
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Berteanu pose la question : I need help with this proposition:
"It exists x a real number that for every y real number 5*x-2*y*y=1
This is false.
Let x be from R.
And I need an y real number that 5*x-2*y*y!=1
Please,could you help me? Penny Nom lui répond. |
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The line of intersection of two planes |
2015-12-09 |
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Rabz pose la question : Determine the vector equation for the intersection between the two given planes
2x+7y equal to 14,x+z equal to 7 Penny Nom lui répond. |
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Drawing an arc |
2015-12-04 |
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hassan pose la question : how to draw a curve long 1m with an angle of 22.5? Penny Nom lui répond. |
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The height of a truncated cone |
2015-12-04 |
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Jack pose la question : I need to build a truncated cone that has a top of30 inches and a base of 64 inches . The sides need to be at a 64.5 degree angle. This will determine the height. Can this be calculated? Penny Nom lui répond. |
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The sweep angle of a video camera |
2015-11-25 |
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Franc pose la question : a television camera is 30ft from the sideline of a basketball court 94 ft long. The camera is located 7 ft from the mid court. through what angle must it sweep in order to cover all action on the court? Penny Nom lui répond. |
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The range of f(x)=(2x+2)/(x-1) |
2015-11-25 |
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Nazrul pose la question : f : R to R is a function which is defined by f(x)=(2x+2)/(x-1).
Is f(x) an onto function? Please explain.
What is the range of this function?
Thank you very much for your previous help. Harley Weston lui répond. |
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How much does the Earth curve over a one foot distance? |
2015-11-24 |
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Sean pose la question : Hi, I am trying to figure out how much the earth curves over a one foot distance. I'd like to be able to draw the exact arc on a piece of paper. I am an artist and am looking to make glass vessels with the exact curvature of the earth. I read on your site that it curves approximately 8 inches per mile. can I just use simple ratios to break it down into inches?? Thank you so much for your help. Harley Weston lui répond. |
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The measure of an angle in terms of its complement |
2015-11-22 |
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Pam pose la question : Can you please help me so I can help my daughter the equation is the measure of angle v is 4 time the measure of its complement what is the measure of angle v when the equation is 4x+x=90 Penny Nom lui répond. |
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20 million as a percentage of 7.3 billion |
2015-11-18 |
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Nick pose la question : Based on the estimate of the worlds current population (7.3 billion people), I'm trying to work out what percentage of that figure 20 million people would amount to?
(Apologies in advance that I've no idea if the 7.3 billion figure is an American Billion or UK billion)
Thanks for any help.
Nick. Penny Nom lui répond. |
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The area of a domed roof |
2015-11-13 |
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Brandon pose la question : I have a tank with a 13' radius that has a domed roof of 3.5' tall How do I figure out the area in SQFT? Penny Nom lui répond. |
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A concrete container |
2015-11-12 |
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Karstin pose la question : The exterior of a concrete container will be 10 feet by 8 feet by 4 feet tall. The walls and the bottom are 6 inches thick. What will it cost to construct it if concrete is $98.95/cubic yard? Penny Nom lui répond. |
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Roof Square footage |
2015-11-11 |
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Todd pose la question :
Question from Todd:
Good Day.
I have to figure out the square footage of a quonset style roof that's not playing by the rules The building dimensions (rectangular) are 63'x135' the height of the roof is 9.25'. It not an entire Quonset, It's that style of roof,(curved). There are concrete block walls 10' up to the metal roof.
Thank you!
Todd Harley Weston lui répond. |
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The derivative of x^1/3 |
2015-11-08 |
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omar pose la question : hi can help me
am teacher ask me about x^1/3 Derivation definition . Penny Nom lui répond. |
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The domain of cos2x/(sinx-2) |
2015-11-02 |
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Ameen pose la question : Find the domain of:
f(x) = cos2x/(sinx-2) Penny Nom lui répond. |
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The sum of two repeating decimals |
2015-10-22 |
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Kaitlin pose la question : Here is the question I am struggling with:
Is the sum of two repeating decimals always repeating decimal? Explain your answer and give an example.
I answered this question thinking that no you cannot but only when adding 0.9 repeating, but my professor said this was incorrect.
Thanks for the help!
-Kaitlin Penny Nom lui répond. |
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The length of a rectangle |
2015-09-26 |
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Tris pose la question : Hi,
I'm trying to figure out the length of a rectangle but i forgot how. So, the width is
5cm and the perimeter is 34cm. Penny Nom lui répond. |
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Order of operations |
2015-09-12 |
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Tanisha pose la question : I would just like to double check if something like 5x squared times 4x cubed equals 20x to the power of 5??
It's just that we were told you can only answer an equation like this if the base is the same...so does that mean the x part or the whole thing like 5x?
I'm sorry if that didn't make sense!
Thank you for your help!! Penny Nom lui répond. |
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The diameter and circumference of a circle |
2015-09-01 |
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Tracey pose la question : Hello,
I own a custom workroom, I am figuring out fabric quantities or an estimate. When
at the job site, I forgot to measure the diameter of the semi circle shape that I have to
make a cushion for!!!
If the circumference of the semi circle is 165" what would the diameter be, maybe half
this measurement????
I appreciate any help...I basically need the width from left to right to see if I can fit
the cushion on one width of fabric that is 52" wide! Penny Nom lui répond. |
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The distance over a Quonset |
2015-08-20 |
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jane pose la question : total base of hemisphere is 30 ft
apex height is 20 feet
what is total length over dome Penny Nom lui répond. |
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Parallelogram area |
2015-08-04 |
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Nigel pose la question : To find the area of a parallelogram you multiply the base by the height of the parallogram, the height being determined by an imaginary line drawn at right angles to the base. However if I made a parallelogram with joints at each corner and maipulated it to an upright position where the base and sides were at 90 degrees to each other,, I could then simply multiply the base times the height to get the area. Since the sloping side of the parallelogram does not vary in my imaginary jointed model, why can I not simply multiply the base by the sloping side to get the area in the same way that I multiply the base times the height of a square to find its area ? I cannot find the answer to this on the internet although I have searched. Chris Fisher lui répond. |
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Why is the area of square not conserved when it changes to a rhombus? |
2015-06-28 |
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shubham pose la question : Why is the area of square not conserved when it changes to a rhombus, both have equal sides still rhombus have less area than square.?? Penny Nom lui répond. |
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1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 x 0 + 1 = ? |
2015-06-18 |
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Sharon pose la question : 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 x 0 + 1 = ?
I got 1 as my answer despite BODMAS making it 12 because logic tells
me I ought to place brackets around the first set of repeated addition. Could you
please clarify this for me? Thank you 😊 Harley Weston lui répond. |
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2^48 - 1 |
2015-06-13 |
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Soham pose la question : The number 2^48-1 is divisible by two numbers between 60 and 70. The sum of
the two numbers is? Penny Nom lui répond. |
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The amount before profit and overhead |
2015-06-12 |
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kelly pose la question : I have an existing amount of $22,750.00. this includes the profit at 10% and overhead at 10%.
How do I remove the profit and overhead in order to come up with the original starting figure? Penny Nom lui répond. |
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The surface area of a triangular prism |
2015-06-03 |
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Alex pose la question : Find the surface area of a triangular prism with Isoceles triangles and dimensions 4 feet by 6 feet Penny Nom lui répond. |
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The volume of a pipe |
2015-06-02 |
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gordon pose la question : What is the formula to find out how many gallon of water in a length of pipe tried your answer on 8inch at 50feet did not work out Penny Nom lui répond. |
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A pentagon inscribed in a circle |
2015-05-30 |
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Victoria pose la question : find the area of a regular pentagon inscribed in a circle with radius 3 units Penny Nom lui répond. |
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The perimeter of a rectangle |
2015-05-28 |
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Imran pose la question : The length of a rectangle is x+3 centimetres.
The width of the rectangle is x-1 centimetres.
Find an expression in terms of x for the perimeter of the rectangle.
The perimeter of a rectangle The perimeter of a rectangle
Give your expressions in it's simplest form.
The perimeter of a rectangle The perimeter of a rectangle
Thank You. Penny Nom lui répond. |
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Prove that you cannot factor x squared + 5 |
2015-05-28 |
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lily pose la question : the question is: prove that you cannot factor x squared + 5 Robert Dawson lui répond. |
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The perimeter of a quarter circle |
2015-05-21 |
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Bethany pose la question : The perimeter of a quarter circle is 3.57. What is the quarter circle's radius? Penny Nom lui répond. |
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The intersection of a plane and a cone |
2015-05-16 |
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Tom pose la question : Is there a way to derive an equation that describes the perimeter of the intersection of a plane and a cone regardless of the angle of the plane to the cone. Assume that the plane does not cut through the base of the cone, the x, y, z location of the vertex is known, the distance from the vertex to the plane through the axis is know., and that the angle of the cone is known. Chris Fisher lui répond. |
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A pile of mulch |
2015-05-15 |
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Justin pose la question : I have a pile of mulch that measures 19 feet wide at the bottom and has a height of 6 feet. I need to know how many yards of mulch I have.
Please help and help with the formula for further use. Thank you! Penny Nom lui répond. |
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An angle of depression problem |
2015-05-14 |
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haxir pose la question : find the height of the balloon directly above a town if the measure of angle of depression of another town 5km from the first town is 20°!6` Penny Nom lui répond. |
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A word problem |
2015-05-08 |
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JAMES pose la question : A businessman bought a number of similar articles for a total of sh. 6000. Three of the articles turned out to be defective with no resale value. He sold the remaining articles at 12.5% each above the cost price making a total profit of sh 480. How many articles had he bought? Penny Nom lui répond. |
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The surface area of a hemisphere |
2015-05-05 |
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Mandy pose la question : How can I show that the total surface are of any solid hemisphere is 75% of the area of the full sphere? Penny Nom lui répond. |
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The method of elimination |
2015-05-01 |
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oreanna pose la question :
Question from oreanna, a student:
How do u solve 2x+9y=3
7x-4y=-25 in elimination Penny Nom lui répond. |
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Filling a pool with dirt |
2015-05-01 |
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Mike pose la question : I have a hole which a 24 ft pool in it is 10" deep in the the centre and goes to 1" inch at the edge want to fill it in with dirt how many yards of dirt would I need to fill it in Penny Nom lui répond. |
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The volume of a sphere |
2015-04-30 |
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Cassidy pose la question : How do you find the radius of a sphere that has volume 36pI? Penny Nom lui répond. |
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The volume of a cube |
2015-04-30 |
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megan pose la question : What's the volume of a cube with a side length of 6? Penny Nom lui répond. |
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The surface area of a cut pipe |
2015-04-27 |
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ARUN pose la question : dear Sir,
please advise me , how to calculate the surface area of a pipe with diameter of 630 mm and thickness of 67 mm which is cut in a angle of 22.5 degree.
please show me how to calculate the surface area of the pipe which cut in an angle.
Thanking you. Harley Weston lui répond. |
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A piecewise function |
2015-04-25 |
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uday pose la question :
f(x)={x^2+3x+2 / x+2, x(not equal to)=-1
{4, x=-1
how to find domain and how the graph looks like Penny Nom lui répond. |
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Locating the center of a circle that forms an arc |
2015-04-23 |
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Ken pose la question :
Find the Cartesian coordinates of the center of an arc with the given location of the beginning and end points and radius length. Not the midpoint of the circumference but the actual point that the arc
is drawn around.
I know their are two answers depending on the direction of the arc. Unless we assume that all arcs are drawn counter clock wise.
Thanks
Ken
Harley Weston lui répond. |
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Two cars approaching an intersection |
2015-04-16 |
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Engabu pose la question : Car A is traveling west at 50km/h & car B is traveling north at 60km/h. both are headed for the intersection of the two roads. At what rate are the cars approaching each other when car A is 3km & car B is 4km from the intersection? Penny Nom lui répond. |
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Two airplanes |
2015-04-14 |
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john pose la question : two planes leave an airport at the same time, one going northwest (N35*W)at 400 mph and the other going east at 332 mph. How far apart are the planes after 4 hours to the nearest mile? Penny Nom lui répond. |
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The area of a circle given the circumference |
2015-04-12 |
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F pose la question : How do you find the area of a circumference of 6?
Thanks. Penny Nom lui répond. |
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The perimeter of a quarter circle |
2015-04-10 |
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Riley pose la question : How do you find the perimeter of a quarter circle when the radius is 56? Penny Nom lui répond. |
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On what day of the week did 1994 begin? |
2015-04-05 |
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tayyaba pose la question : there were 365 days in the year 1993
the first day of the year was friday.
on what day of the week did 1994 begin? Penny Nom lui répond. |
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The weight of a steel block |
2015-04-04 |
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Mark pose la question : the weight of a steel cube 37 inches X 28 inches X 7 inches Penny Nom lui répond. |
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n^2 is a multiple of 100 |
2015-03-30 |
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Rahul pose la question : I have to prove that n^2 is a multiple of 100 is necessary or
Sufficient condition (or both) for n being multiple of 10 Penny Nom lui répond. |
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The game of 24 |
2015-03-28 |
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Suzanne pose la question : I love this game! Cannot figure out 4,9,10,16 to equal 24? Help! Penny Nom and Claude Tardif lui répond. |
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The weight of two dogs |
2015-03-17 |
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Renee pose la question : Darlene's dog weighed 5 times as much as Leah's dog. Together, the dogs
weighed 84 pounds. How much did each dog weigh?
Write an equation and solve Penny Nom lui répond. |
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A cone of maximum volume |
2015-03-16 |
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Mary pose la question : I have to use a 8 1/2 inch by 11 inch piece of paper to make a cone that will hold the maximum amount of ice cream possible by only filling it to the top of the cone. I am then supposed to write a function for the volume of my cone and use my graphing calculator to determine the radius and height of the circle. I am so confused, and other than being able to cut the paper into the circle, I do not know where to start. Thank you for your help! -Mary Robert Dawson lui répond. |
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The height of an equilateral triangle |
2015-03-12 |
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anna pose la question : I am anna and i am in 7th grade.
i am trying to find the height of and equilateral triangle, all sides equaling 4 inches Penny Nom lui répond. |
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The area of a quadrilateral |
2015-03-11 |
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Joel pose la question : Diagonal ac of quadrilateral ABCD is 60cm and the lengths of perpendiculars to
It from the opposite vertices are 4.2cm and 5.8 cm find the area of the quadrilateral
ABCD Penny Nom lui répond. |
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Angles of elevation and depression |
2015-03-08 |
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Timmy pose la question : Joel is walking down a street and sees a 115 ft tall building in front of him. He stops 190 feet from the base of the building at the tip of the building's shadow. Round answers to three decimal places.
A. If there was a piece of rope from the top of the building to Joel, how long would it be?
B. What is the angle of elevation from Joel to the top of the building?
C. Margaret says that she could find the angle of depression from the top of the building to Joel by subtracting the angle of elevation from 90°. Is she correct? Explain. Penny Nom lui répond. |
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A man is standing on top of a building |
2015-03-06 |
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kiki pose la question : a man of height 1.5m standing on top of a building of height 48.5m views another building across the square. he observe that the angle of depression of the bottom of the building is 40 degrees and the angle of depression of the top of the building is 5 degrees. Both buildings stand on the same level
a) calculate the distance of the man from the base of the building across the square measured along the line of sight Penny Nom lui répond. |
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Solve x=r(t-sin(t)) for t |
2015-02-28 |
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David pose la question : I don't know how to write the function of t(x) by x=r(t-sin(t)).
Can you teach me that? Harley Weston lui répond. |
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The radius of a cylinder |
2015-02-26 |
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Rose pose la question : Hi. I want to know how to find the radius of cylinder.
When I have height (35cm) and area of the curved surface(880sq.cm).
I know the formula is 2πr(h+r). But I can't understand how to find it's radius.
Please help me. I really need your help. Penny Nom lui répond. |
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A limit |
2015-02-19 |
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genc pose la question : Lim (27x^3-1) / (3x-1)
X-> 1/3 Harley Weston lui répond. |
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The center and radius of a circle |
2015-02-06 |
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ariana pose la question : I need to find the center and the radius of this circle. I don't know how to put 9/2
than square it into a fraction.
x^2 + 2x + y^2 +9y=5 Penny Nom lui répond. |
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The volume of a cone |
2015-02-05 |
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Linda pose la question : How do you calculate the volume of a cone that is 25cm high and has an angle of 20 degrees? Penny Nom lui répond. |
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Ratio of gas to oil |
2015-02-02 |
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Chris pose la question : I would like to find the gas oil ratio for a 2 cycle engine.
I have the gallons of gas and the ounces of oil used by
the engine, but I want to find what the ratio is. For example
I used 5.675 gallons of gas and 5 ounces oil what is the ratio?
Please explain step by step, and I understand there are 128oz in
a gallon. Harley Weston lui répond. |
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128/(-16)/(-2) |
2015-01-28 |
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jackie pose la question : 128/(-16)/(-2) I was wondering if you can show me how to work this question out Harley Weston lui répond. |
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Scheduling meetings with pairs of people |
2015-01-22 |
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Jacey pose la question : I am trying to figure out a formula/system to pair up a list of people so they meet with each other every month, but they rotate who they meet with. Right now I have 13 people and I would like to just type in their names and then have the system put each person with someone else every month and rotate so no one gets the same person twice. Can this be done? Victoria West lui répond. |
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The game of 24 |
2015-01-21 |
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aaron pose la question : 24 game whants me to use 11 14 5 and 9 to make 24 allowed (+ - dividing and multiplying) Penny Nom lui répond. |
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The height of a building |
2015-01-20 |
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Emily pose la question : A man 2m high observes the angle of elevation to the top of the building to be 70 degrees. And the angle of depression to the bottom of the building to be 19 degrees. How tall is the building? Robert Dawson lui répond. |
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The length of a roll of paper |
2015-01-12 |
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Peggy pose la question : roll of paper 3ft wide and roll equals 500 sq ft how long would the roll be? Penny Nom lui répond. |
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A difference quotient |
2015-01-12 |
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Sasha pose la question : Simplify the difference quotient
f(x) − f(a)/ x-a
if x ≠ a.
f(x) = x^3 − 12
Penny Nom lui répond. |
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The volume of a lake |
2015-01-10 |
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Peter pose la question : If a lake is 8 acres in size and 10 feet deep how many gallons of water does it contain Penny Nom lui répond. |
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Selling items at a reduced price |
2015-01-09 |
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Kent pose la question : I have an item I sell for $19.95 and make a profit of $10.97 for each sale.
If I reduce the price to $14.97, my profit is $5.99 each sale.
Is there a formula to determine how many more I would need to sell
at $5.99 per sale to make the same net cash (profit) as selling at $10.97 per sale? Penny Nom lui répond. |
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The units digit of a prime |
2015-01-08 |
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Patricia pose la question : Every prime number greater than 10 has a digit in the ones place that is included in which set of numbers below 1 3 7 9 or 1 3 7 or 0 2 4 5 6 8 or 1 3 5 9 Walter Whiteley lui répond. |
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The degree of a polynomial |
2015-01-05 |
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Nichole pose la question : How do I determine the degree of polynomials? I've searched this on sites but they are
all so confusing! Is there a simple explanation or way to find what the degree is? Some
examples are: 6x^4 10x^2yz^5 and 3m^2n^7-10m^8. I also have to say that I am
under the impression that this symbol ^ means the number after it is an exponent. Robert Dawson and Harley Weston lui répond. |
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1.5% of 1 trillion |
2014-12-30 |
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Kgosi pose la question : How much is 1.5% of 1 trillion? Penny Nom lui répond. |
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Curvature of the Earth |
2014-12-29 |
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Jimmy pose la question : Both batteries died in my scientific calculator and I have lost my formula for the heigth of the curvature of the earth between two points on the surface. I used degrees and miles. I only had to enter the distance between the two points on the surface and the formula gave me the hieght the earth raised between the two points. Robert Dawson lui répond. |
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The perimeter of a quarter circle |
2014-12-26 |
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Maisy pose la question : This is the question that I got for a math worksheet.
The radius of a quarter circle is 5 miles. What is the quarter circle's perimeter?
Use 3.14 for pi. Penny Nom lui répond. |
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A line segment of length root 5 |
2014-12-15 |
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angela pose la question : On the dot grid below, draw and label a line segment with length square root 5
the dot grid is 8 by 10 Penny Nom lui répond. |
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Planar curves |
2014-12-13 |
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ann pose la question : what does planar curve mean in your definition of a cone? Penny Nom lui répond. |
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30% profit |
2014-12-05 |
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Lyn pose la question : I would like to know a formula that I would use on a standard calculator to calculate a 30% profit margin on an item.
If I purchased an item at $7.70 how would I calculate 30% profit for me, not just 30% mark up? Penny Nom lui répond. |
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1999 equations in 1999 unknowns |
2014-11-28 |
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Subrahmanya pose la question : Solve the following system of 1999 equations in 1999 unknowns :
x1+x2+x3=0, x2+x3+x4=0……., x1997+x1998+x1999=0,
x1998+x1999+x1=0, x1999+x1+x2=0.
(in x1,x2,...................,x1999 the numbers 1,2,.............,1999 are subscripts) Penny Nom lui répond. |
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What is 20 and 3/5 of 10? |
2014-11-26 |
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Jeannine pose la question : What is 20 and 3/5 of 10? Question is written exactly this way.
Is this 20 3/5 times 10 (103/5 times 10), or is it 20 and (3/5 times 10)? Penny Nom lui répond. |
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Doubling the dimensions of a cone |
2014-11-21 |
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Hannah pose la question : If the volume of a cone of height 10 cm is 261.8 cm3, show that this
volume is increased by a factor of 8 if the dimensions of the cone are doubled. Penny Nom lui répond. |
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(x-3)^2-(x+3)^2 |
2014-11-13 |
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Bernice pose la question : (x-3)^2-(x+3)^2 Penny Nom lui répond. |
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What is -3 squared? |
2014-11-12 |
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Christine pose la question : On a math test, it said "What is -3 squared?" It did NOT say "What's is (-3)squared"
The teacher's explanation is that if there are no brackets or parenthesis, you ALWAYS square the number first then do the negative, so the answer should be -9, but I can't find anywhere that confirms this.
Help please. Robert Dawson lui répond. |
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Two quadratic polynomials |
2014-10-28 |
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khushboo pose la question : The zeroes of a quadratic polynomial x^2+ax+b are 'c' and 'd'
and the zeroes of a quadratic polynomial x^2+cx+d=0 are 'a' and 'b'.
find the numerical value of a+b+c+d where a, b, c and d are non zero integers. Penny Nom lui répond. |
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A 10-foot piece of PVC pipe |
2014-10-21 |
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David pose la question : A plumber has a 10-foot piece of PVC pipe. How many 9/5-foot pieces can be cut from the 10-foot piece ? Penny Nom lui répond. |
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Sieve of Eratosthenes |
2014-10-03 |
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Hope pose la question : using Sieve of Eratosthenes to determine for in instance prime numbers between 1 to 200, to what nth number should i stop?, 4th, which is 11 or what? Robert Dawson lui répond. |
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The perimeter of a parcel of land |
2014-09-18 |
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Shirley pose la question : What is the perimeter of a parcel of land that is 564 acres square Penny Nom lui répond. |
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A tangent to a curve passing through a point not on the graph |
2014-09-15 |
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Aquilah pose la question : For the curve y = x2 + 3x, find the equations of all tangent lines for this graph
that also go through the point (3, 14). Penny Nom lui répond. |
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The diagonals of a cube |
2014-09-04 |
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Rukshanth pose la question : How many diagonals does a cube have? Harley Weston lui répond. |
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The sum of two numbers is 52 |
2014-09-01 |
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Blake pose la question : The sum of two numbers is 52 and the difference is 10. What are the numbers? i used to be real good at this stuff? Penny Nom lui répond. |
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The perimeter of a triangle |
2014-08-21 |
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Phyllis pose la question : What is the perimeter of a five acre triangle with one side being 250 feet and the second side would be at a 90 degree angle.
Thank you. Penny Nom lui répond. |
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The equation of a circle |
2014-08-14 |
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jennifer pose la question : hi there My name is Jennifer and residing in Denmark. I am a student and I wrote to you because i am having trouble in finding out the equation for the circle using
(x-a)^2 + (y-b)^2 =3D r^2.The diameter of this circle is d=3D 44,514 cm.
I have attached a drawing of my problem..thanks Penny Nom lui répond. |
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Ratios ond percents |
2014-08-13 |
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aswathi pose la question : if the ratio of cost price and selling price of an article is be as 10:11,the percentage of profit is Tyler Wood lui répond. |
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The area of a quadrilateral |
2014-08-06 |
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Rahul pose la question : find the area of the quadrilateral whose side measure9cm,40cm,28cm,15cm and in which the angle between the first 2 sides is a right angle Penny Nom lui répond. |
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The area of a kite |
2014-08-04 |
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Janis pose la question : How do you calculate the area of a kite with the diagonals 24cm and 48cm? Chris Fisher and Penny Nom lui répond. |
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Expand and simplify [x-3][x+3] |
2014-07-16 |
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symion pose la question : Expand and simplify [x-3][x+3] Penny Nom lui répond. |
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A 5 sided lot |
2014-07-10 |
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mia pose la question : have the feet numbers of three sides, but the forth side is in a "V" so it has two figures.
Question: can i add the two figures of the "v" together to get one figure, so then I would have the figures for all four sides. Harley Weston lui répond. |
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A ladder against a wall |
2014-07-09 |
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thabo pose la question : A ladder 6.5m long,leans against a wall so that the top of the ladder is 4.8m from the ground.what is the angle of elevation of the ladder to the top of the wall Penny Nom lui répond. |
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The method of elimination |
2014-07-05 |
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leo pose la question : please explain how can i solve this problem
3x-6y=-38
6x-9y=44
using elimination and simultaneous method thank you :) Penny Nom lui répond. |
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The width of a rectangle |
2014-07-02 |
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john pose la question : if the area of a rectangular field is 90 sq. m and its length its is 19 m find its width Penny Nom lui répond. |
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A triangle on the surface of the Earth |
2014-06-26 |
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Christine pose la question : A, B and C are three towns, the bearing of B and C from A being 310 degrees and 220 degrees, and their distances from A are 510km and 700km respectively. Find the bearing of B from C to the nearest minute. Robert Dawson lui répond. |
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50+9-13 multiplied by 2= |
2014-06-25 |
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Adrian pose la question : 50+9-13 multiplied by 2= Penny Nom lui répond. |
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An oval pool |
2014-06-21 |
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steve pose la question : I have a 16' x 28' oval pool that is buried 24" deep inground. The dig site is dug
2' wider all the way around the pool. I need to back fill this area with stone. I want to fill this area with 6 to 8"
of stone. How many tons of stone will this take?
Thanks you
Steve Penny Nom lui répond. |
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The number of standard deviations |
2014-06-15 |
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Dawn pose la question : Suppose that, at a certain college, the average weight of all male students is 160 pounds with a standard deviation of 30 pounds. A certain male student weighs 145 pounds. Determine how many SD's his weight is above or below average. Penny Nom lui répond. |
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Profit |
2014-06-14 |
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roudha pose la question : find the profit of one item if it was bought for AED 180 and sold for
AED 275. assume that the additional costs are AED 25 . Penny Nom lui répond. |
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The area of a circle of circumference 32.69 meters |
2014-06-11 |
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coco pose la question : Find the area of a circle with a circumference of 32.69 meters. Penny Nom lui répond. |
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Bags of sand |
2014-06-06 |
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Robert pose la question : We have a section that is 20ft long by 14ft wide and 4inches deep, the bags of sand are
.5 cubic ft. How many bags of sand do we need to fill this space evenly. Penny Nom lui répond. |
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The volume of a wedge |
2014-05-21 |
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steve pose la question : I need to figure the volume of a wedge / right triangle, the dimensions of the right triangle is L1(10'-5"), L2 (10'-6"), H (14'-9.5") height of L1 is 0'-0" height at intersect L2/H is 3'-3" Penny Nom lui répond. |
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The equation of a line |
2014-05-16 |
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Michael pose la question : Find the equation of a line that passes through (2,-1); the sum of the x- and y-intercepts is 2. (There are two answers) Penny Nom lui répond. |
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A schedule for 2 teams of 10 |
2014-05-07 |
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John pose la question : How can I set up a schedule for 2 teams of 10 on a team to play each individually against each other over a 10 day span at 10 different course with 10 different start times each day. I was looking to not repeat any competition. As an example, Team A would consist of players 1-10, Team B would consist of players 11-20. I would want to have 10 start times a day for 10 days where a member of team A plays a member of team B each day without repeating any matches and any of the same courses and not repeating any of the same start times. Any help in this would be GREATLY appreciated!!!! Victoria West lui répond. |
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A cone of vision |
2014-04-29 |
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David pose la question : It is known that a fish in water looking up has a 97 degree "cone" of vision that sees "through" the surface of the water. If a fish lies 4 inches below the surface, the cone forms a window (circle) smaller than if a fish lies 8 inches below the surface. What is the ratio of inches of depth to the radius of the circle on the surface that is its visual window? Penny Nom lui répond. |
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Profit and loss |
2014-04-29 |
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Anoushka pose la question : A man sells two tables of the same price. On one he makes a profit of 10 percent and on the other he suffers a loss of 10 percent.Find his loss or gain percent on the whole transaction. Robert Dawson lui répond. |
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A triangular chicken pen |
2014-04-27 |
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Cierra pose la question : Margaret has two lengths of fence, 20 meters and 24 meters, for two sides of a triangular chicken pen. The third side will be on the north side of the barn. One fence length makes a 75° angle with the barn. How many different pens can she build if one fence is attached at the corner of the barn? What are all the possible lengths for the barn side of the pen?
Not sure what they are asking here... please show step by step what to do! Thank you so much! Penny Nom lui répond. |
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The volume and radius of a sphere |
2014-04-27 |
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grace pose la question : How do you find the radius of a sphere when all you know is the volume? Penny Nom lui répond. |
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The derivative of sin(x) |
2014-04-26 |
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Lucky pose la question : f(x)=Sin(x), by first principle its f'(x)...show me how to solve such problem. Penny Nom lui répond. |
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What was the selling price? |
2014-04-25 |
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Con pose la question : Apple built 40 32GB wifi iPads, gave away two in a contest, and sold the rest at two times the manufacturing price. If the company's total profit was $10,782, what is the selling price of one of these iPads? Penny Nom lui répond. |
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A quadratic equation given the roots |
2014-04-23 |
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Sarah pose la question : How do you find the quadratic formula when you're given just the roots ... X=-3 X= 1/3
Thanks ! Robert Dawson lui répond. |
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Golf for 6 |
2014-04-21 |
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barbara pose la question : We are a group of 6 golfers. We play in groups of 3 for 5 days.
How can I arrange the groups that everybody plays with everybody else at least once?
Thanks. Victoria West lui répond. |
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Golf with 3 teams of 20 |
2014-04-21 |
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Joshua pose la question : Thank in advance for this great service
Golf - new - 3 teams of 20 - to create 20 unique groups of 3
For example use 3 teams of 3
1a 2a 3a
1b 2b 3b
1c 2c 3c
So groups are
1a 1b 1c
2a 2b 2c
3a 3b 3c
Groups can only have one a, one and one c - and that combo should be unique Victoria West lui répond. |
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Barrels of oil |
2014-04-16 |
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daryl pose la question : Looking for an accurate number to use when calculating barrels per inch in a a tank with the following dimensions:
Nominal diameter - 15'-6", nominal height - 16ft, nominal capacity - 500 barrels. These are commonly referred to as 500x16 tanks.
Currently we are using 2.6 barrels per inch. We need 180 barrels for a full load so I'm trying to figure out how many total inches I need to load 180 bbl. This has been a matter of debate for some time. Thanks for your help. Harley Weston lui répond. |
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The surface area of a circular dome |
2014-04-10 |
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Shafiqah pose la question : Is this a dome's surface area formula??
{{2 × π r × h square units}}
Is the surface area of the floor for the dome is calculate too in this formula?
Thanks for answering. =) Robert Dawson and Penny Nom lui répond. |
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The sides of a triangle |
2014-04-06 |
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Michael pose la question : I am supposed to sove for the length of side "b" of an irregular triangle. I am given the following:
Side a: 65'
Side b: Find this length
Side c: 50'
Angle A: unknown
Angle B: unknown
Angle C: 52 degrees
I am supposed to use the law of cosines to solve for side "b" and my teacher
says there is no mistake in the "givens" for the problem. I do not see how
this can be done using the law of cosines and i have not figured out how to sove for
angle B to use the law of cosines. Penny Nom lui répond. |
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The Pythagorean Theorem |
2014-03-30 |
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brenae pose la question : The Pythagorean Theorem, what is it? Penny Nom lui répond. |
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A schedule for 6 people |
2014-03-29 |
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John pose la question : How do I set up a schedule where six people are here for ten of twenty days.
Arranged in rotating groups of three, so everyone works with everyone else.
Everyone works with everyone else at least once and everyone works ten days. Victoria West lui répond. |
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Curvature of the Earth |
2014-03-28 |
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Max pose la question :
Recently I read the answer to a question proposed by someone on this site.
The question : What is the rate of curvature per mile on Earth?
The answer given : Use Pythagoras' Theorem to solve for the answer, given a 1 mile side
and a side as the radius. The hypotenuse minus the radius is your answer of drop/mile or curve/mile.
My conjecture : Why go through all of that work if the distance is one? Something like
{1/diameter} would would fine for such a problem. Seems like a lot of work for no reason.
I understand the practical application of Pythagoras' Theorem in this certain situation, as you would need
to use a^2+b^2=c^2 for any distance greater than one [mile]..
It just seems excessive and unnecessary if you're solving for curve / one mile. Robert Dawson lui répond. |
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A table of values |
2014-03-27 |
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Marisol pose la question : A table value X 0,1,2,3,4,5,6 and Y 3,7,11,15,19,23,27 . what relationship of X to Y is represent by which equation? A . y= 4x. B y =x+3 . C y =4x+3 or . D y =4x-3 Penny Nom lui répond. |
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Two overlapping arcs in a square |
2014-03-15 |
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Jean pose la question : I have a square with side 4 cm. There are two overlapping arcs going from vertex to diagonal vertex. The other two vertices are the center of the arcs, which are shaded. How do I find the area of the shaded arcs? The overlapping arcs when shaded resemble a long thin football
Thank you for your help. Penny Nom and Walter Whiteley lui répond. |
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The angle of depression |
2014-03-08 |
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Ranger_minor pose la question : A woman of height 1.4 metres standing
on the top of a building 34.6 metres high
views a tree some distance away.
she observes that the angle of depression of the bottom of the tree
is 35 degrees and the angle of depression of the top of the tree
is 29 degrees.
assume that the building and the tree are on level ground :
1). calculate the distance of the woman
from the top of the tree measured along her line of sight. Penny Nom lui répond. |
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The equation of a circle |
2014-03-07 |
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Balraj pose la question : I have to draw a circle x^2+y^2 =8x . please tell me how to understand these coordinates ? please elaborate , on how to understand these types of equations. Penny Nom lui répond. |
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The diameter of the base of a cone |
2014-02-23 |
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elwin pose la question : i have a sector of a circle that has 120 degree and 6 cm length. What will be the diameter of the base of the cone.
and what is the diameter of the angle is changed to 180. Harley Weston lui répond. |
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Three investment partners sharing the profit |
2014-02-22 |
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Ayatullah pose la question : Hello;
We are three partners and bought a property at 2050000 and sold at 2300000.
Details of investment of the partners
X= 1500000
Y= 400000
Z = 150000
My questions are
1) How could i calculate percentage of investment of each partner?
2) How could i deduct 30% commission from each partner in profit?
3) How could i distribute the profit amongst the partners?
Thanks in advance Penny Nom lui répond. |
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The growth of a tree |
2014-02-16 |
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Emily pose la question : If a tree is 10 ft tall after 2 years and 25 ft tall after 5 yrs , find the rate of change of growth
Of the tree if y is the height in ft and x is the number of years. Penny Nom lui répond. |
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The grade of a road as a percent |
2014-02-14 |
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Emily pose la question : What is the grade of the road shown below expressed as a percent rounded to one decimal place?
Rise is 40feet
Run is 380 feet Penny Nom lui répond. |
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The volume of a cone |
2014-02-08 |
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hibba pose la question : why is the volume of right circular cone divided by 3? Penny Nom lui répond. |
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A triangle has angels in the extended ratio of 2:5:8 |
2014-02-06 |
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Rubina pose la question : a triangle has angels in the extended ratio of 2:5:8. find the measure of
all three angles? Penny Nom lui répond. |
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Order of operations |
2014-02-04 |
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Alex pose la question : Hi there,i got problem with order of operation.Can you please help to find a solution for this?
Thank u beforehand
6-3(7+2)+(2+4)/3-4. Penny Nom lui répond. |
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The volume of a frustum |
2014-02-02 |
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mike pose la question : volume of frustum R23", r 18", h 16" Penny Nom lui répond. |
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Conics |
2014-02-01 |
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Kassidy pose la question : Hey, I have searched through all the questions about conics and how
people use them in the real world, but none of them were very specific
on how they are applied and the process, why it's so important etc.
I have a project due asking these questions and it's been very difficult
finding the right answer, if you could name jobs, how they are use and
specifically applied that would be greatly appreciated. Penny Nom lui répond. |
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$9.50 in coins |
2014-01-15 |
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dana pose la question : you have $9.50 in coins. it has twice as many nickels as quarters and three times as many dimes as nickels. how many of each coin do you have? Penny Nom lui répond. |
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On what day of the week was July 4, 1904? |
2014-01-11 |
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Madi pose la question : Hi guys,
I have a question. July 4, 1903, was a Tuesday. On what day of the
week was July 4, 1904? If you could give me an equation that would
work for any question like this, that would be GREAT!
Your fellow math scholar (in training),
Madi Penny Nom lui répond. |
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When would one flip the inequality sign? |
2014-01-09 |
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Natasha pose la question : Would one flip the inequality symbol in this equation: (explain why)
(-9a)/(-9) > 81
And please explain in what circumstances one would flip the inequality sign
THANKS! Penny Nom lui répond. |
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Profit as a percentage |
2014-01-04 |
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Dane pose la question : If i brought a card for £5 and sold it for £10 what is my profit percentage? 50% or 100% Penny Nom lui répond. |
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25% profit |
2014-01-02 |
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Finn pose la question : Hello,
The question is all about buy-and-sell business.
Problem:
Pencil - $6 for whole sale price
$8 if I sell the item
How do I get the 25% profit? (you can change the whole sale price and the retail price[if i sell the item])
if I buy the pencil at 24 pieces and sell it at 24 pieces. Penny Nom lui répond. |
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The slope of the line y=-2x+5 |
2013-12-29 |
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victoria pose la question : what is the slope of the line with the equation y=-2x+5 Penny Nom lui répond. |
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Can 100r^2-81z^2 be factored? |
2013-12-08 |
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Rosa pose la question : Can 100r^2-81z^2 be factored? Penny Nom lui répond. |
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Fractions and square roots |
2013-12-04 |
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arionne pose la question : How do you solve a square root with improper fractions like 121 over 49 Penny Nom lui répond. |
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What is the slope of this line? |
2013-12-01 |
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Charlene pose la question : What is the slope of this line? Penny Nom lui répond. |
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How many cords of wood is this? |
2013-11-17 |
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melody pose la question : 5.5 ft wide and 24ft long and 10ft wide how many cords of wood is this? Penny Nom lui répond. |
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A sloped concrete wall |
2013-10-30 |
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Brad pose la question : We are planning on pouring concrete in a wall form that is sloped. One end is 73 inches tall, and it tapers to 24 inches tall over a distance of 348 inches. It is flat on bottom and sides and is 12 inches thick. Thanks. Penny Nom lui répond. |
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The perimeter of a rectangle |
2013-10-24 |
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sana pose la question : if the length is given 70 m and the breadth is given as 40 m find the perimeter of the rectangle Penny Nom lui répond. |
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The domain of a derivative |
2013-10-10 |
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Renee pose la question : I am looking to find the domain of a derivative of a radical function,
one such as: f(x) = the square root of (8 − x).
I am kind of unclear on how domains work for derivative.
I don't understand how you take a function's domain and use that to
find the derivative's domain.
Thanks! Penny Nom lui répond. |
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A line through (5, 1) |
2013-10-08 |
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allison pose la question : find an equation in standard form for line passing through point (5,1) and perpendicular to line x=4 Penny Nom lui répond. |
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A triangle problem |
2013-10-02 |
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raneem pose la question : ABC is a triangle in which : BC=20cm. M(<B) =29 and m(<C)=73 . D is the midpoint of BC
Find the length Of AB and AD approximated to 2 decimal places Penny Nom lui répond. |
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Two teams of 4 playing 4 rounds of golf |
2013-09-29 |
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Tom pose la question : We would like to play a ryder cup format with two teams of 4 playing 4 rounds of golf. Three of the rounds would be pairs playing each other and one round would be singles. How can we set up the foursomes so we balance the number of times we play with every other golfer. Victoria West lui répond. |
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Price, revenue and profit |
2013-09-22 |
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lorraine pose la question : What price maximizes revenue? What price maximizes profit?
The only data I'm given is total output, total revenue, and total cost.
I'm not sure how to set up a formula Penny Nom lui répond. |
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The number of cords on a pile of wood |
2013-09-18 |
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Gary pose la question : a cord of wood is 4 feet by 4 feet by 8 feet, how much wood is a row that is 16 in by 5 foot by 32 feet? Penny Nom lui répond. |
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If the earth was made of a ball of string |
2013-09-18 |
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Tammy pose la question : My 9 year old son asked me a question and I have no idea how to work it out! Please can you help?
If the earth was made of a ball of string and you unravelled the string how long would it be? Assuming the string is 5mm thick. Penny Nom lui répond. |
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Using trig to find the height of a hill |
2013-08-14 |
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Anna pose la question : From the top of a hill, the angles of depression of two successive milestones on a level road, which leads straight away from the hill, are 5degrees and 15degrees respectively. Fine the height of the hill.
Suggestion: BE is drawn perpendicular to AD. Find BE, then BD, finally CD.
Thanks :) Penny Nom lui répond. |
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A system of equations |
2013-08-13 |
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Nina pose la question : 3x-2y=8
-x+3y=5
What is the solution of the system of equations Penny Nom lui répond. |
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An equation in slope-intercept form |
2013-08-12 |
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Brittney pose la question : write an equation in slope-intercept form of the line that is parallel to the grapg of y=-3/4x+6 passes through -8,-5 Penny Nom lui répond. |
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Four equations |
2013-08-08 |
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may pose la question : HI how to solve this 4 equations?
A+C = 0
-4A+B-8C+D=1
3A+16C-8D=-29
-12A+3B+16D=5 Robert Dawson lui répond. |
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Practical uses of trigonometry |
2013-08-06 |
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tharindu pose la question : use of trigonometry Penny Nom lui répond. |
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The angle of elevation of the sun |
2013-07-03 |
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Maurice pose la question : A vertical pole with a length of 7m cast a shadow with a length of 5m. Calculate the angle of elevation of the sun and include a diagram. Penny Nom lui répond. |
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a cube-b cube-a+b= ? |
2013-06-16 |
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saryu pose la question : a cube-b cube-a+b= ?
find the answer Penny Nom lui répond. |
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(4- 4cos^4 x)/(sin^2 x) |
2013-05-18 |
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Agnes pose la question : How I can solve this question :
Simplify (4- 4cos^4 x)/(sin^2 x) and write in terms of sin x Penny Nom lui répond. |
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The surface of a solid |
2013-05-07 |
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mustafa pose la question : I am doing a research paper on solid surface applications . Part of the project is to find four at least 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 solid surface are used in our world today and I really can't find anything.. Thanking you in advance, mustafa Penny Nom lui répond. |
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Profit margin |
2013-05-06 |
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Arron pose la question : I have the retail price of $45.50. This price reflects a gross profit margin of 47%. How do I calculate the original cost of the item? Penny Nom lui répond. |
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Points of intersection |
2013-05-02 |
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Bianca pose la question : Find the sets of values of k for which the line y=kx-4 intersects the curve y=x^2-2x at two distinct points. Penny Nom lui répond. |
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Bags of pre-mixed concrete |
2013-04-12 |
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Bruce pose la question : Hello there,
I need two cubic yards of concrete for a playgound I am
installing for my kids. That much i have figured out. I am stumped
over the number of 25kg bags of pre-mixed concrete i will need
to accomplish my goal.
Your help would be greatly appreciated.
Thanks
Bruce Harley Weston lui répond. |
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The equation of a line |
2013-04-04 |
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Miranda pose la question : My coordinates provided are (6, 6) and (-8, 9) and i need to put this into ax=bx=c format. I remember the equation to find the slope of y2-y1/x2-x1 to get the slope. However when i put that back into the y=mx+b format it still leaves me with a lot of variables. Please help :) Penny Nom lui répond. |
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A gravel pile in the shape of a triangular pyramid |
2013-04-04 |
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Casey pose la question : Hello
Right now I am stuck and I feel embarrassed because I feel like the answer is so easy I should know it.
I am working on a project and need to find a volume of gravel it will take to occupy this triangular prism like area. I am not sure what formulas I should use whether it be that for the volume of a pyramid or something more complex? Basically it forms a right triangle at one side then from there all points slope to one singular point about 10412mm away.
I am attaching a picture drawn up in paint with the actual dimensions to clear up any confusion.
Thank you for any help.
Casey Penny Nom lui répond. |
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Question |
2013-04-04 |
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Casey pose la question : Hello
Right now I am stuck and I feel embarrassed because I feel like the answer is so easy I should know it.
I am working on a project and need to find a volume of gravel it will take to occupy this triangular prism like area. I am not sure what formulas I should use whether it be that for the volume of a pyramid or something more complex? Basically it forms a right triangle at one side then from there all points slope to one singular point about 10412mm away.
I am attaching a picture drawn up in paint with the actual dimensions to clear up any confusion.
Thank you for any help.
Casey Penny Nom lui répond. |
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We can't write sinx and cosx as a finite polynomial. |
2013-03-31 |
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rimoshika pose la question : prove that we can't write sinx and cosx as a finite polynomial. Walter Whiteley lui répond. |
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A markup followed by a discount |
2013-03-23 |
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edward pose la question : A shopkeeper marks his goods to gain 35%. He allows 10% discount for cash payment. What is his profit percent when he sells the goods for cash? Penny Nom lui répond. |
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Percent profit: State exam question |
2013-03-12 |
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tony pose la question : which is the correct way to figure 30% profit?
1)
1000 product
500 labor
50 permit
1550 total cost
1550x1.3=2015
2)
1000 product
500 labor
50 permit
1550 total cost
1-.3=.7
1550/.7=2214 Harley Weston lui répond. |
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state exam question |
2013-03-12 |
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tony pose la question : which is the correct way to figure 30% profit?
1)
1000 product
500 labor
50 permit
1550 total cost
1550x1.3=2015
2)
1000 product
500 labor
50 permit
1550 total cost
1-.3=.7
1550/.7=2214 Harley Weston lui répond. |
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A messy arithmetic expression |
2013-02-24 |
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niiaryee pose la question : (((((5^2*4^3)1/5+9^3/3)+(25+(4*5)/15)^2-10)/10/2)3))))) Penny Nom lui répond. |
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The tangent to a circle at a point on the circle |
2013-02-22 |
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Andrew pose la question : What is the equation of the line tangent to the circle with equation x^2+y^2=25 at the point (-4,3) Penny Nom lui répond. |
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Your profit should be 20% of your cost |
2013-02-21 |
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anis pose la question : if the customer says your profit should be 20% of your cost..
1) my selling value should be cost +20% of cost = SP
or
2)cost / 0.80 = SP which is correct...if the second answer is right how should i justify my customer Penny Nom lui répond. |
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Related rates |
2013-02-17 |
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Ishaak pose la question : A hemispherical bowl is filled with water at a uniform rate. When the height of water is h cm the volume is π(rh^2-1/3 h^3 )cm^3, where r s the radius. Find the rate at which the water level is rising when it is half way to the top, given that r = 6 and the bowl fills in 1 minute. Penny Nom lui répond. |
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The continuity of f(x,y)=ln(x^2+y^2) |
2013-02-17 |
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anu pose la question : the question says we have to find the points in the plane where the function is continuous:
f(x,y)=ln(x^2+y^2) . here we aren't given a particular point (x,y) where we have to check a function's
continuity.
what is to be done if we have to check continuity over the whole domain of the function?
please help . Harley Weston lui répond. |
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The equation of a circle |
2013-02-11 |
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mhd pose la question : Complete the equation of the circle centered at(0,4) with radius 3 Penny Nom lui répond. |
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4*4+4*4+4-4*4=??? |
2013-02-06 |
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Jacky pose la question : 4*4+4*4+4-4*4=??? Penny Nom lui répond. |
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What is the domain of f(x)=sin(ln(x))/ln(x)? |
2013-02-06 |
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Behrooz pose la question : Hi, the following problem may be interesting:
What is the domain of f(x)=sin(ln(x))/ln(x)?
Be careful, domain is not obvious.
Best regards
Behrooz Penny Nom lui répond. |
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The fourth side of an irregular polygon |
2013-02-01 |
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Emran pose la question : I have a irregular polygon. I know 3 of the 4 sides, and 2 of the angles. A-B is 285, B-C is 149, and C-D is 310. Angle B is 135 degrees. and Angle C is 45 degrees. Is there a formula to solve for the final side? Thanks. Penny Nom lui répond. |
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We have 2 teams of 6 couples each that play 6 games |
2013-01-25 |
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Denise pose la question : We put together a game night where we have 2 teams of 6 couples each that play 6 games. We haven't been able to figure out an arrangement that allows each couple to play each game with a different couple from the opposite team (i.e. Team A couples play every game with a different couple from Team B). Is this possible? It works with 2 teams of 5 couples each. Chris Fisher lui répond. |
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Maximize profit |
2013-01-19 |
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Chris pose la question : A firm has the following total revenue and total cost function.
TR=100x-2x^2
TC=1/3x^3-5x^2+30x
Where x=output
Find the output level to minimize profit and the level of profit achieved at this output. Penny Nom lui répond. |
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The weight of a pipe full of water |
2013-01-16 |
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joe pose la question : how do you figure out the weight of a pipe full of water Harley Weston lui répond. |
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A shed roof |
2013-01-12 |
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christine pose la question : A roof on a shed is 7.3 ft wide has an incline of 20 degrees what is the height? Penny Nom lui répond. |
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3x6)+(12divided by2)-8= ? |
2012-12-17 |
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christina pose la question : hi my question that's been bothering me is what's
(3x6)+(12divided by2)-8= ????? Penny Nom lui répond. |
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If n is odd, then n^2 - 3 is even |
2012-12-11 |
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Tracy pose la question : Prove the statement:
For all integers n, if n is odd, then n2 - 3 is even. Penny Nom lui répond. |
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The angles of elevation and depression |
2012-12-03 |
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Chelsey pose la question : a person on a balcony of one building looks towards a second building. if the angle of elevation to the top of the second building is 25 degrees, the angle of depression to the bottom of the second building is 17 degrees, and the balcony of the first building is 22 feet above the ground, what is the height of the second building? Penny Nom lui répond. |
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Two quadratic equations |
2012-11-22 |
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fahmie pose la question : graph and solve the intersection of the following equations:
x^2+y^2=4
x^2+2y=4 Penny Nom lui répond. |
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Difference of squares |
2012-11-19 |
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Qelibar pose la question : Please factorise x^2y^2 - 4 Penny Nom lui répond. |
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The square of any odd number, decreased by 1, is divisible by 8 |
2012-11-16 |
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bailey pose la question : Prove that the square of any odd number, decreased by 1, is divisible by 8 Penny Nom lui répond. |
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How much should I price the earrings? |
2012-11-13 |
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Sharon pose la question : I want to sell some earrings and make a $12.00 profit on them I have to pay a
35% commission on them. How much should I price the earrings? Penny Nom lui répond. |
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4+4x5+4= ? |
2012-10-31 |
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Bob pose la question : 4+4x5+4= ? Harley Weston lui répond. |
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How fast is the distance between the aircraft and the car increasing? |
2012-10-24 |
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Steven pose la question : At a certain instant an aircraft flying due east at 240 miles per hour passes directly over a car traveling due southeast at 60 miles per hour on a straight, level road. If the aircraft is flying at an altitude of .5mile, how fast is the distance between the aircraft and the car increasing 36 seconds after the aircraft passes directly over the car? Penny Nom lui répond. |
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Composition of functions and one to one |
2012-10-17 |
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Ariana pose la question : If f o g are one to one function,does it follow that g is one to one? Give reasons for your answers Penny Nom lui répond. |
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The degree measure of the central arc of a circle |
2012-10-17 |
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Crystal pose la question : On a circle with radius of 12 cm is an arc of length 20 cm. What is the degree measure of the central angle used to make this arc? Penny Nom lui répond. |
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Profit |
2012-10-05 |
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kathie pose la question : find the profit income is $500 expenses $120 Penny Nom lui répond. |
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Profit and discount |
2012-09-24 |
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ally pose la question : A wholesaler purchased a wheat for $150 per tonne.He sold it at $170 per tonne.Calculate the percentage profit to (1 decimal place)if the wholesaler offered a 12% discount on the selling price.What could be the new selling price? Penny Nom lui répond. |
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A profit of 35% |
2012-09-07 |
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Jack pose la question : If a product cost me $10.00 and I want a profit of 35% what is my sell price? How do I figure the sale price to make a 35% profit on the sale? Penny Nom lui répond. |
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The volume of a sphere |
2012-08-18 |
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Rohit pose la question : why isn't volume of a sphere = Area of a semicircle x the circumference.
i.e. if we revolve a semicircle around its axis we get a sphere Penny Nom lui répond. |
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5 + 5 + 5 - 5 + 5 + 5 - 5 + 5 x 0 = |
2012-07-29 |
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Tom pose la question : 5 + 5 + 5 - 5 + 5 + 5 - 5 + 5 x 0 = Harley Weston lui répond. |
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John's electronic store |
2012-07-25 |
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Jora pose la question : Electronic Store
John opened an electronic store in December. During his first month,
He sold 10 LCD TVs and 20 Plasma TVs. His income during that
month was $12800. In January, he sold 25 LCD TVs and 40 Plasma
TVs for an income of $27600.
In February he projects to sell 30 LCD TVs and 50 Plasma TVs.
If John expenses are $28900 in February, how much money will he
have after paying the expenses? Penny Nom lui répond. |
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A volume of revolution |
2012-07-15 |
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Tewodros pose la question : Let f(x) = e^x and g(x) = x^1/2 both be defined on [0,1]. Consider the region bounded by f(x), g(x), x = 0, x = 1. Rotate this region about the y-axis and determine the volume using the shell method. Harley Weston lui répond. |
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The angular elevation of the sun |
2012-07-14 |
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VINEET pose la question : WHAT IS ANGULAR ELEVATION OF THE SUM Penny Nom lui répond. |
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A cylinder is to be filled with peas. |
2012-06-12 |
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Silje pose la question : Hi! How can I solve the following question without the use of a calculator?
"A cylinder is to be filled with peas. It is done like this: At 12:00 o'clock you put 1 pea in, at 12:01 you put 2 peas in, at 12:02 you put 4 peas in, at 12:03 you put 8 peas in, and so on.
This continues until 14:00 o'clock (two hours later), when the last peas are put in and the cylinder is full. At what time is the cylinder half full?" Robert Dawson lui répond. |
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9-3(2+6)/6-2*5 |
2012-06-08 |
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Sammi pose la question : Hi there,
I am doing a practice test for my admittance into a college accounting program
and I am really confused by this equation.
The answer I got was way off what the test answer sheet says it should be.
The question is
9-3(2+6)/6-2*5
If you could explain how the answer beccomes 35 that would be greatly apprciated!!
Thank you! Robert Dawson lui répond. |
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Multiples |
2012-05-28 |
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Kenneth pose la question : If I understand correctly , a multiple is a product of two numbers. For example some of the multiples of 6 are 6, 12, 18, 24, 30, etc. I just multiplied 6 by 1, 2, 3, 4, 5, etc.
Are the multiples of a fraction, for example, 2/3, determined in the same way? Are they 2/3, 4/3, 6/3, 8/3, 10/3, etc., or are they instead, 2/3, 4/6, 6/9, 8/12, 10/15, etc.?
Or do fractions have no multiples? Penny Nom lui répond. |
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Sharing the profit |
2012-05-14 |
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Mafiza pose la question : A and B started a business by investing $6000 and $8000 respectively. At the end of the year, a profit of $2100 is made. How much amount will A get as his share of profit? Penny Nom lui répond. |
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An equation of the form y=mx |
2012-04-17 |
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Samiya pose la question : what would be an equation of the form y=mx with the points (-2, 6) and (1, -3) for the line? Penny Nom lui répond. |
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Profit as a percent |
2012-04-14 |
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Anson pose la question : The cost price of a CD is $50 and its marked price is $105. If the
selling price is $88, find the profit percent. Penny Nom lui répond. |
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The spread of a rumor |
2012-04-09 |
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Roohi pose la question : The function f(t) = a/(1+3e^(-bt)) has also been used to model the spread of a rumor. Suppose that a= 70 and b=3 0.2. Compute f(2), the percentage of the population that has heard the rumor after 2 hours. Compute f'(2) and describe what it represents. Compute lim t approaches infinity and describe what it represents. Penny Nom lui répond. |
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The period T of a pendulum |
2012-03-27 |
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Ashley pose la question : The period T of a pendulum is given in terms of its length, l, by T=2pi sqrt(l/g) where g is the acceleration due to gravity(a constant)
a. find dT/dl
b. what is the sign of dT/dl
c. what does the sign of dT/dl tell you about the period of the pendulums? Penny Nom lui répond. |
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The equation of a line |
2012-03-26 |
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Danielle pose la question : Hello, could you help me figure out what the equation of the line is in the form of Ax+By=C with the points (-2,0) and (0,3)?
Thank You! Penny Nom lui répond. |
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A vertical line passing through (10,4) |
2012-03-16 |
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Isabelle pose la question : Hi! My question is this:
Write the equation of each line described:
A vertical line passing through (10,4)
I would really appreciate your help!
Thanks,
Isabelle Penny Nom lui répond. |
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An increase/decrease in profit |
2012-03-13 |
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Thanikasalam pose la question : It is understood that increase/decrease in profit for current year compared to the previous year is done by the formula (x-y)/y, with x=profit on current year and y=profit on previous year. How do we derive this formula?
If we work on this formula of calculating increase/decrease in profit, we get x/y-1
* = (x-y)/y
= x/y - y/y
= x/y - 1
How do you justify the 1 in the equation above. How to derive the formula and how do i prove it? Penny Nom lui répond. |
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A storage box with a slanted roof |
2012-02-13 |
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Sophia pose la question : Hi!
I have another problem.
The diagram shows a side view of a box which is used to store small logs of
wood for burning in a fire place. The slopping lid has an overhand of 15cm.
a) Calculate the total length of the slopping lid to the nearest cm.
b) When the lid is open above ground will the end of the lid be?
P.S. Please see attached. Penny Nom lui répond. |
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The curvature of the earth |
2012-02-08 |
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sean pose la question : Question from sean, a student:
Two people 1.8 metres tall walk directly away from each other until they can no longer see each other (due to the curvature of the earth, which has a radius of about 6378 km).
A) Find a function relating the height of two identical objects with the distance between them using the scenario above as an example.
B) Sketch this function (you may use Graphmatica if you wish). Over what domain and range does the function exist?
C) Describe this relation in practical terms. Harley Weston lui répond. |
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Two sectors of a circle |
2012-02-03 |
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Wayne pose la question : I am not even sure what to ask. I have to two lengths of feet and an angle of degrees, and I have to find the area?
**Problem attached
Thanks,
Wayne Penny Nom lui répond. |
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1 + 3 + 3^2 ...+3^(n-1) = 3^n - 1/2 |
2012-01-27 |
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Vicki pose la question : I am trying to find out how to do show how this proof was worked.
Here is the end result 1 + 3 + 3^2 ...+3^(n-1) = 3^n - 1/2
This equation was used to find the number of white triangles in the Sierpinski Triangle Walter Whiteley lui répond. |
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Four apples and two oranges cost Rs. 30... |
2012-01-13 |
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nasr pose la question : Four apples and two oranges cost Rs. 30, and one apple and 3 oranges costs Rs.15.How much does each apple and each oranges cost? Harley Weston lui répond. |
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A volume of revolution |
2012-01-11 |
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john pose la question : find volume of solid generated by revolving the region in the first quadrant bounded by the curve y squared=x cubed, the line x=4 and the x-axis about the line y=8. The answer in the back of the book is 704 pi divided by5 Penny Nom lui répond. |
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Sum and difference of squares |
2011-12-31 |
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Anne pose la question : Se x e y são números reais distintos, então:
a) (x^2 + y^2) / (x - y) = x + y
b) (x^2 + y^2) / (x - y) = x - y
c) (x^2 - y^2) / (x - y) = x + y
d) (x^2 - y^2) / (x - y) = x - y
e) Nenhuma das alternativas anteriores é verdadeira. Harley Weston lui répond. |
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Three sides of a triangle |
2011-12-24 |
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saba pose la question : the three sides of a triangular lot have lengths 10,11and 13cm,respectively.
find the measure of its largest angle and the area of the lot? Penny Nom lui répond. |
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The volume of a cylinder |
2011-12-22 |
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luke pose la question : what is the volume of a cylinder that is 30 mm in diameter and 70 cm high?
can you please write the equation out in full for me to help understand it better. thanks Penny Nom lui répond. |
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The number of digits in a number base m |
2011-12-22 |
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Jash pose la question : Assume there is a number system of base m.
The one property of this system is: If 2 numbers written in this system, which have 'a' and 'b' as the number of digits are multiplied, then the product of the 2 numbers will have a number of digits which is a function f(a,b).
In other words, as long as the number of digits of the 2 numbers are constant, the number of digits of their product is a constant.
Find m. Robert Dawson lui répond. |
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Water is flowing into a cup |
2011-12-19 |
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Tim pose la question : A cup has a radius of 2" at the bottom and 6" on the top. It is 10" high. 4 Minutes ago, water started pouring at 10 cubic " per minute. How fast was the water level rising 4 minutes ago? How fast is the water level rising now? What will the rate be when the glass is full? Penny Nom lui répond. |
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A cube of ice is melting |
2011-12-05 |
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Emily pose la question : a cube of ice (i.e.) each side is of the same length) is melting at a rate such that the length of each side is decreasing at a rate of 5cm per hour. how fast is the volume of the cube decreasing (in cubic cm per hour) at the instant the length of each side is 25cm? Penny Nom lui répond. |
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Water pouring into a conical tank |
2011-11-21 |
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Patience pose la question : Hi my name is patience and I'm having a problem with this question.
Water pours into a conical tank of semi vertical angle 30 degrees at the rate of 4 cm^3/s, where h is the depth of the water at time t. At what rate is the water rising in the tank when h = 10 cm?
Thank you Penny Nom lui répond. |
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The slope of a line |
2011-11-10 |
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Sara pose la question : Line k lies in the xy-plane.
The x-intercept of line k is -4.
And line k passes through the midpoint of the line segment whose endpoints are (2,9) and (2,0).
What is the slope of line k?
Give the answer as a fraction. Penny Nom lui répond. |
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What was the cost price of the article? |
2011-11-10 |
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tashana pose la question : By selling an article for $320,the profit was 20% of the cost price.what was the cost price of the article. Penny Nom lui répond. |
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The area of a circle |
2011-10-17 |
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Winney pose la question : If the diameter of a semicircle is 3 feet what is the area. Penny Nom lui répond. |
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One central circle and three tangent circles |
2011-10-16 |
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Margaret pose la question : You have one central circle and three or more circles tangent to the outside of the circle of varying radii. You know the x,y coordinates of the centers of the other circles. If you now remove that central circle (and pretend you never knew where it was), can you calculate its center in x,y coordinates? Chris Fisher lui répond. |
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A reservoir has the shape of an inverted cone |
2011-10-03 |
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Roger pose la question : a reservoir has the shape of an inverted cone whose cross section is an equilateral triangle. if water is being pumped out of the reservoir at a rate of 2m^3/sec, at what rate is the depth of the water changing when the depth is 40 meters? Penny Nom lui répond. |
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A hemispherical bowl with a lead ball inside |
2011-09-27 |
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Jean pose la question : "(a) Water is being poured into a hemispherical bowl of radius 3 inch
at the rate of 1 inch^3/s. How fast is the water level rising when the
water is 1 inch deep ?
(b) In (a), suppose that the bowl contains a lead ball 2 inch in
diameter, and find how fast the water level is rising when the ball is
half submerged." Penny Nom lui répond. |
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Composition of functions |
2011-09-05 |
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Jenna pose la question : Let f(x)=x^2-1 and g(x)=1-2x. Find the indicated values.
1. f(g(1)) and g(f(1))
Thanks,
Jenna Penny Nom lui répond. |
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The height of a fluid in a horizontal tank |
2011-07-24 |
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jason pose la question : Same set up as many others, cylindrical tank on its side, but I am interested in defining the change in volume and/or fluid level as a function of time at a constant volumetric outflow. I plan on hooking a pump to the tank so "gpms' will be constant. I have a couple different sized tanks and pumps so I want a general equation. Thanks for your help. Harley Weston lui répond. |
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A reel of paper |
2011-06-03 |
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keith pose la question : if a full reel of paper has 7750 metres on it with a diameter of 1240mm and a core diameter of 100mm how can work out the thickness of each strip of paper therefore allowing me to work out the metreage of the roll when its half in diameter at say 620mm Penny Nom lui répond. |
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A rational number |
2011-05-17 |
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owais pose la question : according to definition of irrational number "a number which cannot be
expressed in p/q form is called irrational number"
square root of 2 is a irrational number but if i round off the digit correct
to two decimal places so it becomes 1.41 and we can easily convert
into p/q form so it is a rational number ??? Penny Nom lui répond. |
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Dividing the profits |
2011-04-19 |
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Tracy pose la question : I need to know how to come up with the answers to the following problems. I need to be able to show my work. So can you help me on how to come up with the answers to questions like these. Thanks.
Three individuals form a partnership and agree to divide the profits equally. X invests
$9,000, Y invests $7,000, Z invests $4,000. If the profits are $4,800, how much less
does x receive compared to having the profits divided in proportion to the amounts
invested by X, Y, and Z?
In printing an article of 48,000 words, a printer decides to use two sizes of type. Using the
larger type, a printed page contains 1,800 words. Using a smaller type, a page contains
2,400 words. The article is allotted 21 full pages in a magazine. How many pages must be
in smaller type? ___________
thank you Penny Nom lui répond. |
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The equation of a sphere |
2011-04-16 |
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kanika pose la question : equation of sphere and how to know its center Penny Nom lui répond. |
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Coefficient of variation |
2011-04-14 |
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Braden pose la question : When determining coefficient of variation (CV) or %CV is it possible to calculate %CV for two variables? For instance can %CV be used to determine the precision of 5 data points on a graph using the X and Y coordinates? or does %CV need to be determined for each variable separately? Robert Dawson lui répond. |
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PEDMAS |
2011-04-10 |
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Ross pose la question : 48 ÷ 2 (9+3)
Is the answer 2 or 288? Harley Weston lui répond. |
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Eliminate y |
2011-04-07 |
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Lynn pose la question : 2x + y = 8
y + 3z =5
z + 2w =1
5w + 3x = 9
Form three equations with y eliminated Penny Nom lui répond. |
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A conical container and a spherical balloon |
2011-04-06 |
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Steven pose la question : Water is running out of a conical container 12 feet in diameter and 8 feet deep (vertex down) and filling a spherical balloon.
At the instant the depth of the water in the cone is 4 feet, the radius of the sphere is approximately 4 feet.
The rate of change of the depth of the water in the cone at the instant is approximately ______________ times the rate of change of the radius of the balloon. Penny Nom lui répond. |
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Administration costs and profit |
2011-04-05 |
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brian pose la question : Hi , If I have direct job costs of $100. and my administration is 20 % and I want to make a 15 % profit , how would I calculate the administration and profit and what would be the total of each be and also the final total?
Thanks,
Brian Penny Nom lui répond. |
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Two ships |
2011-04-05 |
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Gevork pose la question : Ship A is sailing due south at 16 mph. At the same time, a second ship B, 32 miles south of A, is sailing due east at 12 mph.
(a) at what rate are they approaching or separating at the end of one hour?
(b) At what rate are they approaching or separating at the end of two hours?
(c) When do they cease to approach each other and how far apart are they at that instant. Penny Nom lui répond. |
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The rate of change of the area of a parallelogram |
2011-04-05 |
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Gevork pose la question : Let a parallelogram have sides of 8 and 12 and let vertex angle A be decreasing at a rate of 2degrees per minute. Find the rate of change of the area of the parallelogram when angle A equals 30 degrees. Penny Nom lui répond. |
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I need to make $1000 profit |
2011-03-28 |
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Kat pose la question : I need to make $1000 profit selling plants for $3 each. My direct cost is $2 per plant and my overhead is $5oo. How many pots (plants = 1 per pot) do I need to make $1000? Penny Nom lui répond. |
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What is x to the power of 0? |
2011-03-23 |
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Jason pose la question : What is x to the power of 0? Robert Dawson lui répond. |
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(3x+4y)^2 - (2x-y)^2 |
2011-03-16 |
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Taiwo pose la question : pls could some one help me with this question? thanks as lot
factorize:
(3x+4y)^2 - (2x-y)^2 Penny Nom lui répond. |
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A family of circles |
2011-03-01 |
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steffi pose la question : Find the equation of the family of the circle passing through the the point of intersection of x^2+ y^2 -4x-28=0 and x^2 +y^2 -4x-20+52=0; the member tangent to x=7. Penny Nom lui répond. |
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A camera's line of sight |
2011-02-26 |
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MJ pose la question : A rocket that is rising vertically is being tracked by a ground level camera located 3 mi from the point of blast off when the rocket is 2 mi high its speed is 400mph At what rate is the (acute) angle between the horizontal and the camera's line of sight changing Penny Nom lui répond. |
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Prove sin x = sin (pi - x) |
2011-02-15 |
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Janet pose la question : Prove sin x = sin (pi - x) Penny Nom lui répond. |
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The equation of a sphere |
2011-02-09 |
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kelly pose la question : what is the equation of a sphere if one of it's diameters has a giving end point of (4,4,4), (8,8,8)? Penny Nom lui répond. |
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(7cubed * 8(exponent6))exponent 6 |
2011-01-29 |
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Shalaine pose la question : What is the exponential form of (7cubed•8(exponent6))exponent 6? Penny Nom lui répond. |
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Profit as a percentage |
2011-01-17 |
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Connie pose la question : I am trying to determine the profit margin on selected items.
ex: A bottle of juice costs me $.70, I sell it at $3.75. How can I determine what my profit percentage is? Penny Nom lui répond. |
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Identify each polynomial by its degree and number of terms |
2011-01-10 |
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betty pose la question : Write in standard form and identify each polynomial by its degree and number of terms. How do you do this? Penny Nom lui répond. |
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If ac = bc ... |
2011-01-04 |
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jamielle pose la question : if ac=bc, then a is not equal to b, c is not equal to zero Penny Nom lui répond. |
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Profit as a percent |
2010-12-19 |
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gaurav pose la question : In the following, which calculation is right to calculate the profit percent.
if profit is 20%- 100*1.2 = 120
if profit is 20%- 100/0.8 = 125? Penny Nom lui répond. |
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Angle of elevation |
2010-12-10 |
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PANKAJ pose la question : angle of elevation of the sun perpendicular72 and base 88 find angle Penny Nom lui répond. |
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The rate of change of (8e^3x)+(27 e^-3x) |
2010-11-23 |
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Aleo pose la question : I am unable to solve this problem:
Find the rate of change of (8e^3x)+(27 e^-3x), with respect to x when x= 0.5 Penny Nom lui répond. |
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A 35% profit |
2010-11-19 |
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Ana pose la question : You have a stamp collection and make a 35% profit by selling it on E-Bay for $2700. Find the original cost of the collection by using the formula:New value × 100 / 100 + percent change = Original value Stephen La Rocque lui répond. |
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How far must the pitcher travel to get to the ball? |
2010-11-04 |
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ken pose la question : A baseball player bunts a ball down the first base line. It rolls 35ft at an angle of 26 degrees with the first base path. The pitchers mound is 60.5 ft from the plate. How far must he travel to get to the ball. Penny Nom lui répond. |
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What is the speed of each car? |
2010-11-04 |
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Jennifer pose la question : two cars are 420 miles apart and traveling towards each other along the same road. They meet in 3.5 hours. One car is traveling 15mph slower than the other. What is the speed of each car?
This must be solved using a system of equation, I have no idea? Stephen La Rocque lui répond. |
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I want to make a 50% profit |
2010-10-29 |
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Debbie pose la question : If my cost on an item is $32.00 and I want to make a 50% profit- What would the retail be? Penny Nom lui répond. |
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Two algebraic expressions |
2010-10-29 |
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chaptay pose la question : what is the difference between x(n^2) and x(n)^2 Penny Nom lui répond. |
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The game of 24 |
2010-10-26 |
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gabrielle pose la question : What is the answer using the numbers 0 0 0 0 (trig and calc are
allowed, all math is allowed) in the game 24? Claude Tardif lui répond. |
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Powers |
2010-10-20 |
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dylan pose la question : how do you write 20736 in exponential form .same for 1728 and 50625.
is there a formula to figure out how to express large know numbers in exponential form. Penny Nom lui répond. |
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The equation of a circle |
2010-10-20 |
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Silvan pose la question : Hi, I just want to find the x,y values for the circumference of a circle...
Lets take a clock having its centre at (0,0) in a graph.
I just want to know how to find the (x,y) co-ordinates for the curved path or the surface of the circle..
Is there any formula to directly align the curved path or the circumference of the circle in a graph for a known radius of a circle..
I feel it will be useful for me to draw a clock in a graph... :-) Penny Nom lui répond. |
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The distance between the origin and a moving point |
2010-09-24 |
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Norma pose la question : I am having problems with this question
find the rate of change of the distance between the origin and a moving point on the graph of the function below if dx/dt=5 cm/sec
y=x^2+2 Penny Nom lui répond. |
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20% profit on the selling price |
2010-09-24 |
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ata pose la question : My cost is 100 and I want to make 20% profit on my selling price (not 20% of the cost). So, what should be calculation formula? Let's say my cost is 493.71 and I want to make 53.28% profit on the selling price; so how to determine the selling price? Penny Nom lui répond. |
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Elimination and substitution |
2010-09-18 |
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Lauren pose la question : Solve one using the method of substitution and the other with the method of elimination.
v
a. y=5x+4
x=2y+1
b. 4x+3y=7
6x-3y=13 Penny Nom lui répond. |
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A building and a flag pole |
2010-09-09 |
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paul pose la question : A flag pole and a building stand on the same horizontal level. From the point p at the bottom of the building,the angle of elevation of the top t of the flag pole is 65 degrees. From the top q of the building the angle of elevation of the point t is 25 degrees.If the building is20 meters high. Calculate the distance pt Penny Nom lui répond. |
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Percentage improvement |
2010-08-26 |
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shahrukh pose la question : Hi...
We had a web page that was taking 12 secs to load. Now it loads in 3 secs.
What is the percentage of improvement or how much faster is it working now.
TO me it looks like it is working 3 times faster or there is a 300% improvement in the loading time.
However my client says its ((12-3)/12*)100 = 75% improved. Which seems illogical on the face of it.
Thanks for your help
Shahrukh Robert Dawson and Chris Fisher lui répond. |
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What is -2^2? |
2010-08-25 |
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alex pose la question : I know that (-2)^2 is 4 but what is -2^2? Robert Dawson and Penny Nom lui répond. |
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How many labels are left on a roll? |
2010-08-13 |
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Melissa pose la question : Is there a simple way to calculate how many labels are left on a roll? I thought there was a way to look at the individual label length, the label thickness and the core diameter and then measure the overall diameter to calculate how many pieces were left, but I'm struggling. I've seen a tool before- I thought we called it a circle calculator, but those parameters were all that I needed to input to spit out the correct count. I never saw what was behind the scenes for this calculation. Ie factoring in revolutions or the number of pieces on each layer, etc. Please let me know if you have any suggestions. Any assistance will be greatly appreciated!!! Thanks! Penny Nom and Tyler Wood lui répond. |
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A fruit seller |
2010-07-31 |
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Nazrul pose la question : 5% of total number of fruits of a fruit seller has been rotten and also 5% of them has been damaged during transportation. What is the percentage profit by which he sells the rest so that he profit 20% as a whole? Penny Nom lui répond. |
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Thickness of sand |
2010-07-07 |
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RHONDA pose la question : In an 18 x 33 ft area how much is 4 yards of sand in inches to cover this area. Penny Nom lui répond. |
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Volume of a styrofoam cup |
2010-06-23 |
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Stacy pose la question : how do you find the volume of a truncated cup with height of 3, top diameter of 2.5, and a bottom diameter of 2 Penny Nom lui répond. |
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Selling price, cost and profit |
2010-06-22 |
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Alex pose la question : The profit on a certain television set is 16.5% of the cost price. If the profit is $330,
Find:
a) the cost price
b)the selling price of the television Penny Nom lui répond. |
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The number of gallons of water in a basement |
2010-05-23 |
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George pose la question : A basement with dimensions 68 ft long by 42 ft wide by 10 ft deep is flooded to the ceiling calculate the number of gallons of water in the basement. 70 Penny Nom lui répond. |
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Difference of cubes |
2010-05-22 |
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Anad pose la question : how can we prove a^3 - b^3 is equal to (a-b)(a^2+ab+b^2)? Penny Nom lui répond. |
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Line of sight |
2010-05-06 |
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David pose la question : I live in St. Joseph, Michigan and there is an ongoing argument regarding line-of-sight over the horizon.
Standing on a 200 foot high bluff here, people swear they can see the top of the Willis (nee Sears) Tower in Chicago, which is about 1653 feet high.
It is my contention that this is actually a "refracted reflection" and not direct-line-of-sight.
So, to settle the argument, I'd sure like some simple explanation for this, even if-and I hope not-I am incorrect.
David Harley Weston lui répond. |
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The rate of change of y with respect to x |
2010-04-29 |
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Tom pose la question : I just had a quick calc question about wording that wasn't ever
addressed in class. When the book says "the rate of change of y with
respect to x", should it be considered how fast y is changing in
comparison to x?
I ask because the textbook says that "y is changing 3 times faster than x,
so the rate of change of y with respect to x is 3." I'm use to rate being
like velocity, as in units of distance per units of time. All we're told
in class is that it's the slope of the tangent line, I was hoping you
could clarify for me what exactly is meant by the wording of a "rate of
change of something with respect to something else". More specifically, what
"rate" and "with respect to" mean within this context?
Thanks for your time Harley Weston lui répond. |
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The height of a flag shaft |
2010-04-25 |
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Sarah pose la question : A man standing 20metres away from a tower observes the angles of elevation to the top and bottom of a flag shaft standing on the tower as 62degrees and 60degrees respectively. Calculate the height of the flag shaft.' Penny Nom lui répond. |
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Profit |
2010-04-21 |
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joyann pose la question : a Raleigh road runner 16" unisex bike which cost $892 was sold for $1052.56 calculate
A. the profit made on the bike
B. the percentage profit Penny Nom lui répond. |
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Exactly two lines of symmetry |
2010-04-11 |
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debbie pose la question : i am looking for a quadrilateral with exactly two lines of symmetry. please help! thank you. Tyler Wood lui répond. |
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The area of a field of view |
2010-04-07 |
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Frank pose la question : I know we have a field of view of 90 degrees and the distance we can cover is 6 miles. What is the area we can cover/view?
A formula would be nice to have since the diameter or distance of the wedge area can change and the degree of the field of view can also change.
Thank you and I look forward to hearing from you.
Frank Penny Nom lui répond. |
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Fitting a sofa through a doorway |
2010-04-06 |
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Yvonne pose la question : Hi, I would be most grateful if you could help me, because I have no idea how to work this out! I am moving from a house to a flat, and the doors in the flat are 70 cm wide. I have a sofa 88 x 88 x 215. Will it go through the door if we tip it sideways at an angle?
Thanks, Yvonne Beck Robert Dawson lui répond. |
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A system of equations |
2010-03-30 |
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samantha pose la question : the equations of two lines are 6x-y=4 and y=4x +2.what is the value of x in the solution for this system of equations? Penny Nom lui répond. |
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The sides of a 30-60-90 triangle |
2010-03-29 |
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maris pose la question : Find the sides of a 30-60-90 triangle whose perimeter is 6. The solution must use systems of equations using 3 variables. Penny Nom lui répond. |
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The area of a polygon |
2010-03-28 |
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John pose la question : Question from John, a student:
How do you find the area of a polygon with any given amount of sides? Harley Weston lui répond. |
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The height of a hill |
2010-03-26 |
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Amber pose la question : A surveying team determines the height of a hill by placing a 12-foot pole at the top
of the hill and measuring the angles of elevation to the bottom and to the top of the pole.
They find the angels of elevation. Describe how to find the height of the hill. Penny Nom lui répond. |
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A radio tower |
2010-03-26 |
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Alex pose la question : The height of a radio tower is 450 feet, and the ground on one side of the tower slopes upward at an angle of 10 degrees. How long should a guy wire be if it is to connect to the top of the tower and be secured at a point on the sloped side 110 feet from the base of the tower? Harley Weston lui répond. |
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A roll of paper |
2010-03-25 |
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keith pose la question : how many yds of paper for a roll with a width of 6.875 and a core of 3 in and a diameter of 40in? Robert Dawson lui répond. |
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The angle of intersection between two lines |
2010-03-25 |
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Madhumitha pose la question : How to find the angle of intersection between a line x=249 and another line which is of the form y=m*x+c; Line1 has a slope of infinity so what does the angle of intersection turn out to be? Or how can i find it? Chris Fisher lui répond. |
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Modelling the roof of a house |
2010-03-23 |
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Sandi pose la question : This question has been haunting my dreams at night. It states the cross section of the roof of a house is modelled by the function y= -5\12|x-12|+5, where y>0 or y. Now I'm suppose to graph the function. b) Find the slope, height, length of sides, and base of the isosceles triangle. c)Explain what transformation must be applied to the graph of y=|x| to obtain the graph of y= -5\12|x-12|+5, where y>0 or y=0. 1st I put the equation into my calculator and graphed it. I got 10 for the height. We have had 2 sub teachers this past week. The first one told me the height should be 12 the other one told me 5. So I'm really confused. If I use my 10 units as height and the Pythagorean Theorem I get my sides to be 26 units the base 48 and my slope I calc to be 5/12. Both teachers are pretty sure I'm wrong and they are right but we all have different answers. Please help put this problem to rest so I can rest soundly at night. Thank you for your time. Penny Nom lui répond. |
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A quadrilateral with 4 known sides and 1 known angle |
2010-03-19 |
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samuel pose la question : Name: Samuel
Status: Student
I have a quadrilateral with 4 known sides and 1 known angle, and I'm trying to evaluate the other angles of my quadrilateral.
By the law of cosines, I can easily find my opposite angle (using the diagonal as a basis for the equation).
However, to find the two remaining angles, I have found no other way so far than to use the other diagonal, which can be found with the equation attached (from geometry atlas).
Is there any simpler way? Robert Dawson and Harley Weston lui répond. |
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Cooling |
2010-03-07 |
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Lori pose la question : If a house is always at 20 degrees celsius.
Water (tea) boils at 100 degrees celsius.
5 minutes later the tea was 70 degrees celsius.
Use an equation to predict the temperature after 20 minutes. Tyler Wood lui répond. |
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Prove A intersect B =X iff A = X and B = X |
2010-03-06 |
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Gloria pose la question : how would you prove A intersect B =X iff A = X and B = X Tyler Wood lui répond. |
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How many CDs and videos did the store sell? |
2010-03-01 |
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dawn pose la question : A used book store started selling CDs and videos. In the first week,the store sold 40 used CDs and videos,at 4.00
per CD and 6.00 per video.The sales for both CDs and videos totaled 180.00 she wrote a system of equations to represent the situation.Then she graph the system of equations
thanks- Dawn Tyler Wood lui répond. |
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The test for some disease is 99% accurate |
2010-02-24 |
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baaba pose la question : Assume that the test for some disease is 99% accurate. If somebody tests positive for that disease, is there a 99% chance that they have the disease? Chris Fisher lui répond. |
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15% profit |
2010-02-21 |
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daviann pose la question : calculate the cost price,given
selling price=$304
percentage profit=15%
what is the answer? Penny Nom lui répond. |
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The angle at which the road is inclined |
2010-02-10 |
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abeth pose la question : a mountain road drops 5 m for every 22 m of road. Calculate the angle at which the road is inclined to the horizontal to the nearest degree. Penny Nom lui répond. |
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Order of operations |
2010-02-07 |
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addie pose la question : (3+10) x 10 - 8 x 4 = Penny Nom lui répond. |
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Everything in a cube 2 miles long? |
2010-01-31 |
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Naresh pose la question : in a book, i got to read this :
Is it possible to pack the entire population of earth and everything that was created by
humankind in a cube whose edges are 2 miles long ?
Is it possible? Thanks. Stephen La Rocque lui répond. |
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The height of a roof |
2010-01-31 |
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carl pose la question : Width of my roof I am building is 5M at baseline, and the pitch is 40%.
What will the height be, and how can I work this out in the future. Penny Nom lui répond. |
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1^3 + 2^3 + 3^3 +4^3 ... n^3 = ? |
2010-01-29 |
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ireimaima pose la question : Hi..
Can u please help me with this question..
I find that when i test eg: n=2 for n (n+1) /4,
it seems that it does not giving me the right answer of 1^3 + 2^3 = 9
but 3/2... i'm confuse..can u please help me..thanks so much
Prove that:
1^3 + 2^3 + 3^3 +4^3………………………………..n^3 = n (n+1) /4 Penny Nom lui répond. |
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Solving a triangle |
2010-01-25 |
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Paige pose la question : how do i solve a triangle with one angle of 73 degrees,
one angle of 32 degrees, and one side of 23cm? Harley Weston lui répond. |
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Angle of incline |
2010-01-20 |
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Alan pose la question : how do I fnd the angle of an incline with a measurement of 0.042 with an adjacent of 1.2mtrs?. Thank You Penny Nom lui répond. |
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A proof by induction |
2010-01-12 |
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Bhavya pose la question : Prove by induction that if Xi >= 0 for all i, then
(Summation Xi from 1 to n)^2 >= Summation Xi^2 from 1 to n Penny Nom lui répond. |
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A proof involving real numbers |
2010-01-11 |
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Amper pose la question : Let a,b is an element of real numbers, and suppose that for every x>0 we have a is lesser than or equal to b+x.
(a) Show that a is lesser than or equal to b.
(b) Show that it does not follow that a is lesser than b.
i'm feeling bad of having no idea with this, hope i you can help me. GRACIAS!! Penny Nom lui répond. |
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Profit increase from 10% to 15% |
2010-01-03 |
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taha pose la question : A shopkeeper sold a pen for $13.20 to a make a profit 10 percent.In order to earn a profit of 15 percent,he should have sold it for? Penny Nom lui répond. |
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A trig question |
2009-12-15 |
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A trig question pose la question : Hey, my name is Candle
I'm in academic math10 and am stuck on my trig... one question I thought I had right because i used the cosine law I got wrong and can't figure out why... here's a copy of the question. (i guessed it was D... but my teacher said it's B)
Thanks
Candle Robert Dawson lui répond. |
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A 4 digit number |
2009-12-15 |
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Lisa pose la question : Billy Club was assigned the task of putting numbers on
all the playground balls used during daily recess. Billy
will number the balls using the following rules:
1. It will be a 4-digit number.
2. The digit in the thousands place will be a 1 or a 2.
3. The digit in the hundreds place will be a 2, 4, or 6.
4. The digit in the tens place will be an odd number.
5. The digit in the ones place will be greater than six.
How many balls can Billy number if he follows these rules? Robert Dawson lui répond. |
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A telephone pole on a slope |
2009-12-14 |
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Marissa pose la question : A 10 meter telephone pole casts a 17 meter shadow directly down a slope when the angle of elevation of the sun is 42 degrees. Find the angle of elevation of the ground. Its a law of sines problem. Penny Nom lui répond. |
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e = m c^2 |
2009-12-09 |
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Jim pose la question : Please explain the following formula:
E=MC2 (squared) Robert Dawson lui répond. |
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Game of 24 |
2009-12-09 |
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Tony pose la question : Checked out all of the previous inquiries into the crazed game, and found none with these particular numbers: 1, 4, 6, 7. I've tried every method I can think of, please Help! Tks. Robert Dawson, Penny Nom and Claude tardif lui répond. |
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How fast is the distance between the two cars decreasing? |
2009-12-08 |
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Jenny pose la question : Two cares are on a collision course toward point P. The paths of the two cars make a 30 degree angle with each other. The first car is 40 km from P, and traveling toward P at 16 km/hour. The second car is 50 km from P, traveling at 20 km/hour. How fast is the (straight line) distance between the two cars decreasing. (Hint: Law of Cosines) Harley Weston lui répond. |
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(9 - x^2)/(x - 3) |
2009-12-04 |
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Sandy pose la question : 9-x^2/x-3
I need to know how to solve this.
Thanks Penny Nom lui répond. |
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(24x3)+(7x8)-(20/5)+(4x7) |
2009-12-01 |
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Marilyn pose la question : (24x3)+(7x8)-(20/5)+(4x7)
Thought I had the answer but the form says no. Could you solve it for me please. Penny Nom lui répond. |
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Three angles and one side of a triangle |
2009-11-16 |
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Esther pose la question : How do i find the sides of an acute triangle if i know the angels are 60,45,75 and i only know one side which is 10? Thanks! Penny Nom lui répond. |
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Maximize profit |
2009-11-14 |
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Willie pose la question : Profit is the difference between Total Revenue and Total Cost.
Therefore, to MAXIMIZE PROFIT you must maximize Total Revenue.
True or False? Explain answer. Penny Nom lui répond. |
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At what rate are the people moving apart? |
2009-11-01 |
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saira pose la question : A man starts walking north at 4 ft/s from a point P. 5 minutes later a woman starts walking south at 5 ft/s from a point 500 ft due east of P. At what rate are the people moving apart 15 minute after the woman starts walking ? Harley Weston lui répond. |
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A linear system |
2009-10-20 |
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marissa pose la question : Solve this linear system
2x-y=5
3x+y=-9 Penny Nom lui répond. |
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Proof that the root of 27 is irrational |
2009-10-18 |
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Scarlet pose la question : How do you prove that the square root of 27 is irrational? Victoria West lui répond. |
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A right triangle |
2009-10-12 |
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Josseph pose la question : A right triangle has an area of 84ft sq. and a hypotenuse 25ft long. What are the lengths of the other two sides? Penny Nom lui répond. |
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Game of 24 |
2009-10-02 |
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trami pose la question : game of 24 by using -4 -7 -7 1? Claude Tardif lui répond. |
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Prove by induction |
2009-10-02 |
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Anonymous pose la question : How can you prove the following by induction:
Any fraction (A / B), where 0 < (A / B) < 1, can be expressed as a finite sum
(1 / c(1)) + (1 / c(2)) + (1 / c(3)) + ... + (1 / c(k)),
where c(1), c(2), ..., c(k) are natural numbers greater than 0.
[ex. (20 / 99) = (1 / 9) + (1 / 11)] Claude Tardif lui répond. |
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-4 squared and (-4) squared |
2009-09-29 |
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Andrea pose la question : Is -4 squared the same as (-4) squared? I am thinking the first is -16 and the second is +16. I am trying to clarify for my students. Penny Nom lui répond. |
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Evaluating -x^2 + (yz - 3)^2 |
2009-09-28 |
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Kathy pose la question : My daughter and I are having trouble solving this equation:
-x²+ (yz – 3)²
if x=-4,y=2 and z=0
We are having difficulty with the -x² part of the equation. Thanks Penny Nom lui répond. |
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How many terms are there in this sequence? |
2009-09-28 |
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tabby pose la question : How many terms are there in this sequence?
5,1,-3,...,-111 Penny Nom lui répond. |
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Probability |
2009-09-27 |
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Ed pose la question : My mother died 3 years to the day after her daughter died. what are the odds of that happening by chance? thanks Chris Fisher lui répond. |
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Order of operations |
2009-09-24 |
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aman pose la question : my question is regarding the fact
i have a formula which looks like this :
(ratio 1 + ratio 2 divided by 2)
so my question is do i add first then divide by 2 or do it all together Penny Nom lui répond. |
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5 x 8 + 6 divided 6 - 12 x 2 |
2009-09-24 |
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Susan pose la question : 5 x 8 + 6 divided 6 - 12 x 2. I am not sure of the rules of operation for this type of question Penny Nom lui répond. |
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Two equations in two unknowns |
2009-09-18 |
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Citizen pose la question : x+-3y=7
-x+4y=7 Penny Nom lui répond. |
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The method of substitution |
2009-09-17 |
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laura pose la question : ok! i really need help with this question plz help!!
x= - 4y +5
x+2y = 7 Penny Nom lui répond. |
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A trillion grains of rice |
2009-09-14 |
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akaila pose la question : can 1trillion rice grains fit in a classroom with the area of 144.4m3 Penny Nom lui répond. |
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Simultaneous equations |
2009-08-28 |
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onias pose la question : solve 3/a - 2/b = 1/2 , 5/a + 3/b = 29/12 Robert Dawson lui répond. |
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y=2x+1 and y=2x-1 |
2009-08-28 |
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MARICELA pose la question : Need help of how to work this problems
y=2x+1 and y=2x-1
First of all what is the difference?
Second I think is easy just to work with the X y with the line in the middle
but how do you get the numbers for each side. Penny Nom lui répond. |
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The game of 24 |
2009-08-27 |
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ANITA pose la question : Help I'm suppose to be a math expert, yet I can not yield 24 from the numbers 8,4,9,9, using each only once. HELP Penny Nom lui répond. |
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An antiderivative problem |
2009-08-13 |
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Indrajit pose la question : ∫4e^x + 6e^-x/(9e^x + 4e^-x)dx = Ax + Bloge(9e2x - 4) + C
then A=?......B=?.....C=?
plz solve it...."^" stands for "to the power of".... Harley Weston lui répond. |
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The leaning tower of Pisa |
2009-08-09 |
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MF pose la question : Would you have any idea how the 'latitude of 44 degrees N" has anything to do with this question and how I would apply it?
The leaning tower of Pisa leans toward the south at an angle of 5.5 degrees. One day near noon its shadow was measured to be 84.02 m long and the angle of elevation from the tip of the shadow to the top of the tower was measured as 32.0 degrees. To answer the question, assume that the tower is like a pole stuck in the ground, it has negligible width. Also, it is important to know that Pisa Italy is at a latitude of approx 44 degrees North because this affects the direction of the shadow.) Stephen La Rocque lui répond. |
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Eye Height Level Found from Visual Angle |
2009-08-07 |
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Jolie pose la question : Hello,
I am trying to figure out what height from the ground a person's eyes are if they have a 12 degree visual angle to a screen that is 58cm away from their eyes?
Thank you. Janice Cotcher lui répond. |
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Highest Common Factor of Two Polynomials |
2009-07-28 |
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Nazrul pose la question : If x+a be the h.c.f. of x^2+px+q and x^2+mx+n, how can I prove that (p-m)a=q-n. Robert J. Dawson & Janice Cotcher lui répond. |
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Inequalities Proof |
2009-07-24 |
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ABOU pose la question : good morning.......a b c are real positive no zero......proof that
sq root(2a/(a+b))+sq root(2b/(b+c))+sq root(2c/(c+a))inferior or equal 3
thank you Janice Cotcher lui répond. |
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Properties of Natural Numbers |
2009-07-24 |
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nazrul pose la question : If m,n,k are natural number how can I prove that (m+n)k=mk+nk. In the proof the properties of natural number should be used. Janice Cotcher lui répond. |
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Proof of a Unique Solution |
2009-07-24 |
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muele pose la question : Find matrix A such that A is not invertible, and
b such that Ax=b has a unique solution Robert J. Dawson lui répond. |
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Selling fish |
2009-07-22 |
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Hemantee pose la question : A fishmonger bought 150kg of fish. he sold 70%of it at the price of Rs90 per kg and the rest at Rs 75 per kg. he made a profit of 42.5 per cent. how much did he pay for the fish. Penny Nom lui répond. |
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Profit as a percentage |
2009-07-15 |
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Jay pose la question : If I buy an item for $3.00 and sell it for $6.00. What is my percentage of profit? Penny Nom lui répond. |
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A roll of paper |
2009-07-05 |
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mark pose la question : is there a simple way of finding out how much is left on a roll of paper. i have read similiar questions and answers on here but all seem very complicated and not being very good at maths does not help me much. some are in inches and all have different figures to mine so if i give my figures hopefully i wil understand it better. the radius of the cardboard core is 52.25mm, the radius of the paper at 2000 linear meters is 158.625mm. the thickness is 0.17mm. when nearing the end of the paper how do i work out how much is left in a simple way. thank you in advance for any help you can give me Harley Weston lui répond. |
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Coffee scoops per cup |
2009-06-29 |
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charity pose la question : if my coffee machine takes 10 scoops for every six cups, how many scoops do i need for 4 cups.
each scoops equals one tbls(.25 oz) Penny Nom lui répond. |
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Prove that the set of all positive odd integers is an infinite set |
2009-06-20 |
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Nazrul pose la question : How can I prove that the set of all positive odd integers is an infinite set.
Thank you in advance. Victoria West lui répond. |
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A difference quotient |
2009-06-17 |
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Sue pose la question : When s(x)=x^3+x, compute and simplify the difference quotient s(x+h)-s(x)/h. Harley Weston lui répond. |
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The product of gradients between 2 perpendiculars lines |
2009-06-11 |
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Alister pose la question : how do i prove that the product of gradients between 2 perpendiculars lines equal to -1.... Penny Nom lui répond. |
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Vectors and the Law of Cosine |
2009-06-08 |
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lauren pose la question : once 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 Janice Cotcher lui répond. |
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Profit margin |
2009-05-26 |
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andreya pose la question : what is the profit margin of a business that spends $200 in order to make $1000 Penny Nom lui répond. |
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Game of 24 |
2009-05-22 |
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Sam pose la question : Using the numbers 7, 3, 2, and 2, how do you get the number 24? Claude Tardif and Harley Weston lui répond. |
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Maximum profit |
2009-05-11 |
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Sally pose la question : a manufacturer of dresses charges $90 per dress up to 100 units and the average production cost is $60 per dress. to encourage larger orders the company will drop the price per dress by .10 for orders in excess of 100. I need to find the largest order the company should allow with the special discount to realize maximum profit. Harley Weston lui répond. |
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A 6 team social softball league |
2009-05-02 |
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Don pose la question : Hi
We have a 6 team social softball league with only two fields. Each team
plays two games each Saturday. We have three time slots 10:00, 12:00
and 2:00 We play for 11 Saturdays and than have a 2 weekend playoff.
All teams prefer double headers vs the split at 10:00and 2:00. How do we
schedule as balanced a schedule as possible and minmize the splits ?
Thanks
Don Laura Morrison and Victoria West lui répond. |
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Game of 24 |
2009-05-02 |
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Barbara pose la question : using the numbers 1,3 7 and 9 only once how do you get the answer of 24 Claude Tardif lui répond. |
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The sum of the roots of a quartic |
2009-04-21 |
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dave pose la question : This is a algebra problem that i am confused about:
The sum of the roots of x^4-x^3+5x^2+4=0 is:
i tried graphing it, but it shows that there are no roots, but the answer is 1. are they wrong? Penny Nom lui répond. |
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12 oz. cup |
2009-04-19 |
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Tom pose la question : I am a ceramic teacher and wanted my students to make a 12 oz. cup, what formula should we use? Chris Fisher lui répond. |
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Exponential form |
2009-04-16 |
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Pete pose la question : Hi,
How do you express ³√h^-4 in exponential form. I am having a lot of
trouble with this one.
thanks
Pete Stephen La Rocque lui répond. |
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The axiom of choice and constructibe sets |
2009-04-10 |
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sydney pose la question : The axiom of choice asserts the existence of certain sets, but does not construct the set. What does "construct" mean here? For example, does it require showing the existence and uniqueness of some function yielding the set? In general, what does it mean to require the existence of a mathematical object be tied to a construction of it? Claude Tardif lui répond. |
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Game of 24 |
2009-04-08 |
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Joe pose la question : How do you get 24 using 6,9,10,10 once. Its called the 24 game.
Joe Harley Weston lui répond. |
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Multiplication of polynomials |
2009-04-07 |
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Carla pose la question : I am struggling to understand Multiplication of Polynomials. No matter how hard I try to understand Multiplication of Polynomials, I just can't get it!
The problem that I am trying to solve is this :
-3x^3y(-y + 2 -x^2 + x) Robert Dawson lui répond. |
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Game of 24 |
2009-04-05 |
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Ramona pose la question : math 24 using 16, 9, 20, 7 Penny Nom lui répond. |
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Profit as a percent |
2009-03-26 |
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Danny pose la question : If I have something that cost me .38 and I want to sell it for $1.00 what is my profit % on this item Robert Dawson lui répond. |
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The rate of change of the volume of a sphere |
2009-03-25 |
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Kaylin pose la question : why the rate of change of volume of a sphere is not constant even though dr/dt is constant? Walter Whiteley lui répond. |
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The optimal retail price for a cake |
2009-03-25 |
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Shawn pose la question : Your neighbours operate a successful bake shop. One of their specialties is a cream covered cake. They buy them from a supplier for $6 a cake. Their store sells 200 a week for $10 each. They can raise the price, but for every 50cent increase, 7 less cakes are sold. The supplier is unhappy with the sales, so if less than 165 cakes are sold, the cost of the cakes increases to $7.50. What is the optimal retail price per cake, and what is the bakeshop's total weekly profit? Robert Dawson lui répond. |
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The sides of a parallelogram |
2009-03-17 |
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Sami pose la question : If ABCD is a parallelogram, prove that line AB is congruent to line CD. Clearly state your reasons and conjectures. Penny Nom lui répond. |
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The midpoints of two sides of a triangle |
2009-03-17 |
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Manis pose la question : Prove that the line joining the midpoint of two sides of a triangle is parallel to the third and half of it. Robert Dawson lui répond. |
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Related rates |
2009-03-14 |
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Jeevitha pose la question : The side of an equilateral triangle decreases at the rate of 2 cm/s.
At what rate is the area decreasing when the area is 100cm^2? Stephen La Rocque lui répond. |
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Related rates |
2009-03-09 |
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Megan pose la question : A plane flying with a constant speed of 330 km/h passes over a ground radar station at an altitude of 3 km and climbs at an angle of 30°. At what rate is the distance from the plane to the radar station increasing a minute later? Harley Weston lui répond. |
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The game of 24 |
2009-03-01 |
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Jeff pose la question : My son in the 5th grade was given a problem for extra credit and could use parents help. He was given the numbers 21, 13, 9, 6 and asked to use each number only once by +, -, /, x the numbers in any order to obtain an answer of 24. Harley Weston lui répond. |
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Collecting an army |
2009-02-25 |
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bevaz pose la question : Question from bevaz, a student:
A ruler orders his chamberlain to collect an army from 30 houses. The servant goes to the first house alone and collects one man. At each house after that he takes the same number of men as he has already collected, so at the second house he goes with one other and so on. How many men did he collect in all? Penny Nom lui répond. |
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Find the resultant of this displacement pair |
2009-02-22 |
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katydidit pose la question : Find the resultant of this displacement pair:
500 miles at 75 degrees east of north and
1500 miles at 20 degrees west of south.
How do I graph this and how do I solve this problem? Penny Nom lui répond. |
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Angle of depression |
2009-02-18 |
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Meeka pose la question : An aircraft flying at an altitude of 2000m is approaching an airport.
If the angle of depression of the airport is 5 degrees, what is the distance from the plane to the airport measured along the ground?
Round your answer to the nearest tenth of a kilometer. Robert Dawson lui répond. |
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A rectangular park |
2009-02-06 |
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Debbie pose la question : A park named Writer's Rectangle opened in town. When asked about the dimensions of the rectangle, the city planner, responded with these clues: ---The diagonals of the rectangular park plus its longer sides together measure seven times one of the shorter sides. ---The length of one diagonal is 250 m longer than one of the shorter sides. Use this information to find the area of the park. Stephen La Rocque lui répond. |
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How much did the statue originally cost him? |
2009-02-06 |
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Debra pose la question : Jim is able to sell a hand-carved statue for $670 which was a 35% profit over his cost. How much ded he statue originally cost him? Penny Nom lui répond. |
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The substitution method |
2009-02-06 |
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amber pose la question : Pleasse help me with this problem
x+y=-2
y-2x=1 Penny Nom lui répond. |
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Calculating markup |
2009-02-03 |
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Tonya pose la question : I'm trying to figure out the formula for the following, I have a product that I want to receive a certain profit, but with this product I also have to pay a percentage of commission to someone. I need to know how to calculate my new selling price taking into account the markup percentage, but I don't want my cut to be lowered. I have calculated the markup percentage to get my new selling price with the commission, but it lowers my cut once I pay the commission and I don't want it to do that. Thanks Penny Nom lui répond. |
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How fast is the visible surface of the earth decreasing? |
2009-01-24 |
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Ray pose la question : A dive bomber loss altitude at a rate of 400 mph. How fast is the visible surface of the earth decreasing when the bomber is one mile high? Harley Weston lui répond. |
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In the shadow of a flagpole |
2009-01-22 |
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La pose la question : How fast is the length of the shadow of an 18 foot flagpole growing when the angle of elevation of the sun is 45 degrees and is decreasing at a rate of 10 degrees per hour? Harley Weston lui répond. |
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Factor x^2 - y^2 |
2009-01-20 |
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Shell pose la question : complete Factor: x^2-y^2 Penny Nom lui répond. |
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Negative rate of change |
2009-01-12 |
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hemanshu pose la question : when i have to find rate of change of decrease in any value my ans comes in negative why?????????? Penny Nom lui répond. |
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A T-shirt fundraiser |
2009-01-11 |
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Andre pose la question : Lou's class is selling T-shirts for a fundraiser. The supplier charges 750$ for the initial design and the set-up plus 5$ for each imprinted shirt. The students sell the shirts for 15$ each.
a)How many T-shirts do the students need to sell to break even?
b)How much profit will the students make if they sell 150 shirts? Harley Weston lui répond. |
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The table of values for y=3x-10 |
2009-01-09 |
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Jade pose la question : How can I know the value of x for y=3x-10 in this table of values pls. include the deatails
if x=-2 y=-16
if x=3 y=-1
but how if y=2 what is x Penny Nom lui répond. |
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30% profit |
2009-01-06 |
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bob pose la question : this is a basic question that I just can't get thru my head.
I know all my cost for a product, if I want to sell at a given profit can I divide by a given
number, example for 30 % divide by .7 or do I multiply?
Is there a simple answer for this? Sure would make my work a lot easier.
Thank you for your time
Puzzled in Ohio Penny Nom lui répond. |
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The sum of the roots of a quartic |
2009-01-03 |
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peter pose la question : How do you find the roots of an equation without graphing? like, i have a problem that says what is the sum of the roots of x^4-x^3+5x^2+4=0. Harley Weston lui répond. |
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System of equations - comparison method |
2009-01-02 |
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nick pose la question : Hi, I am doing a project on system of equations by using comparison method,
but for some reason or another, i can't seem to find any information on the
comparison method at all. So, please would you help me by giving me a website
that you know of that has some information on my method. And, if you know the
answer, can you please tell me why or when do we use system of equations by
using comparison method?
Thank You Robert Dawson lui répond. |
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The area of a triangle |
2008-12-23 |
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ashiya pose la question : Hi,
I have attached figure of the triangle, Can you please help to find the area of Triangle ABC.
Thanks.
Ashiya Stephen La Rocque lui répond. |
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Coefficient of variation |
2008-12-17 |
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JR pose la question : I have read your reponses regarding the coeffcient of variation (CV) and find them very useful. I still have a question about interpreting the CV. Let's that the CV of sample #1 is 3% and that of sample #2 is 12%. Can I report that Sample #2 is 4 times more variable than sample #1? Thanks in advance! Robert Dawson lui répond. |
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The angle between two lines |
2008-12-17 |
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abhi pose la question : how to calculate the angle between two lines, given the length of the lines..
angle should vary from 0 - 360 in the counterclockwise direction Robert Dawson and Harley Weston lui répond. |
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Do all square numbers have an odd number or factors? |
2008-12-11 |
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Amy pose la question : Do all square numbers have an odd number or factors? Victoria West lui répond. |
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Related rates |
2008-11-26 |
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Lyudmyla pose la question : How fast is the volume of a cone increasing when the radius of its base is 2 cm and growing at a rate of 0.4 cm/s, and its height is 5 cm and growing at a rate of 0.1 cm/s? Harley Weston lui répond. |
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The game of 24 |
2008-11-24 |
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Davey pose la question : this has us all stumped. 5 ,5 ,7 ,and9 = 24. Oh may you assist in ending
our brain pain Penny Nom lui répond. |
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Profit as a percentage |
2008-11-21 |
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Nomar pose la question : Cost Price is $ 556,109.64 and Selling price is $ 1,020,936.00, What is the Profit Percentage? Harley Weston lui répond. |
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The path of a small sailboat |
2008-11-19 |
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jane pose la question : a sailor in a small sailboat encounters shifting winds. she sails 2.00 km East
then 3.40 km North East, then an additional distance in an unknown direction. Her final position
is 6.68 km directly east of the starting point. find the magnitude & direction
of the third leg of the voyage. Harley Weston lui répond. |
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Factoring |
2008-11-19 |
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Neji pose la question : How do you factor (y-z) (y+z) (y^4+y^2z^2+z^4) and get (y+z)(y^2-yz+z^2) (y-z) (y^2+yz+z^2) as the answer? Harley Weston lui répond. |
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How far are the boats apart? |
2008-11-14 |
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dom pose la question : Two boats leave port at the same time. They leave at 150 degree angle. One boat travels at 10mph and the other at 20mph. After two hours how far are the boats apart? Penny Nom lui répond. |
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What is -5x+3y=24? |
2008-11-13 |
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Robert pose la question : What is -5x+3y=24??????? Stephen La Rocque lui répond. |
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The angles and sides of a triangle |
2008-11-13 |
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JAMIE pose la question : a triangle with a side(b)37m an angle(C)70degrees and (a)79m find values of angles A and B and length of side c Stephen La Rocque lui répond. |
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How fast is the distance between the airplanes decreasing? |
2008-11-10 |
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Crystal pose la question : At a certain instant, airplane A is flying a level course at 500 mph. At the same time, airplane B is straight above airplane A and flying at the rate of 700 mph. On a course that intercepts A's course at a point C that is 4 miles from B and 2 miles from A. At the instant in question, how fast is the distance between the airplanes decreasing? Harley Weston lui répond. |
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Melting ice on a hemisphere |
2008-10-20 |
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heather pose la question : The top of a silo is the shape of a hemishere of diameter 20 ft. if it is coated uniformly with a layer of ice, and if the thickness is decreasing at a rate of 1/4 in/hr, how fast is the volume of ice changing when the ice is 2 inches thick? Penny Nom lui répond. |
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How much does Luc pay for his tools?? |
2008-10-20 |
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imran pose la question : Luc makes $1 profit on each tool he sells. Marc makes a $2 profit while paying $5 less for his tools than Luc. Marc thus makes $6 more profit for every $100 invested. How much does Luc pay for his tools?? Penny Nom lui répond. |
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An arithmetic series |
2008-10-17 |
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Laura pose la question : In an arithmetic series 5+9+13+...+tn has a sum of 945. How many terms does the series have?
What formula do I use? Penny Nom lui répond. |
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Related rates |
2008-10-16 |
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Gisela pose la question : As sand leaks out of a hole in a container, it forms a conical pile whose
altitude is always the same as its radius. If the height of the pile is increasing
at a rate of 6 in/min, find the rate at which the sand is leaking out when the
altitude is 10in. Penny Nom lui répond. |
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The rate of change of the volume of a cone |
2008-10-15 |
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Barbara pose la question : Suppose that both the radius r and height h of a circular cone change at a rate of 2 cm/s.
How fast is the volume of the cone increasing when r = 10 and h = 20? Harley Weston lui répond. |
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The average rate of change of gasoline used |
2008-10-06 |
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JHulie pose la question : What is the average rate of change of gasoline used, measured in miles per gallons
if you travel 212 miles, then you fill your gas tank up again and it takes 10.8 gallons.
If you designate your change in distance as 212 miles and your change in gallons as 10.8? Penny Nom lui répond. |
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The vertex of a parabola |
2008-09-30 |
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Anne pose la question : How do you find the vertex of the function f(x)=-x squared+7x-6 Penny Nom lui répond. |
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Lines that pass through a point |
2008-09-30 |
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Abigail pose la question : what is the name for a point that a group of lines pass through that contains the letters c e n p i l? Penny Nom lui répond. |
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z(z+1)-x(x+1) / z-x |
2008-09-30 |
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sylvia pose la question : z(z+1)-x(x+1) / z-x
HOW DO I SIMPLIFY THIS Penny Nom lui répond. |
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a(a+1) - b(b+1) |
2008-09-30 |
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Shaun pose la question : I need to factor (a-b) out of the following: a(a+1) - b(b+1). I know it is simple but I cannot remember how. Penny Nom lui répond. |
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How tall is the wall? |
2008-09-29 |
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ash pose la question : you and bob are separated by a tall wall you stand 10 feet further from the wall
than bob your angle of elevation is 37 degrees and his 44 degrees
how tall is the wall? Penny Nom lui répond. |
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Number of factors |
2008-09-18 |
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Austin pose la question : I am stuck on finding what type of number has exactly two factors and
what type of number has an odd number of factors? I need some examples. Penny Nom lui répond. |
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The volume of a box |
2008-09-16 |
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Andre pose la question : volume of the box cubic centimeters
____ X _____ X ______ X =_______
The length is 8.5 Width is 3.4 Penny Nom lui répond. |
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The nth term of a sequence |
2008-09-13 |
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lavett pose la question : what is the Nth term in the sequence when the sequence is 2,4,8,16... and the term numbers are 1,2,3,4... Stephen La Rocque lui répond. |
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Angle of elevation |
2008-09-09 |
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kristy pose la question : A man on the tenth floor of a building shouts down to a person on the street. If the angle of elevation from the street to the man in the building is 35° and the man in the building is 40 feet up, about how far away from the building is the person on the street? Penny Nom lui répond. |
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The height of a tree |
2008-09-09 |
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danice pose la question : At a certain time of day, the angle of elevation of the sun is 30°. A tree has a shadow that is 25 feet long. Find the height of the tree to the nearest foot. Penny Nom lui répond. |
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A security camera |
2008-09-07 |
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Rita pose la question : A security camera in a neighborhhod carnival is mounted on a wall 9 feet above the floor inside a video gallery. What angle of depression should be used if the camera is to be directed to a spot 6 feet above the floor and 12 feet from the wall? Stephen La Rocque and Harley Weston lui répond. |
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Mathematical induction |
2008-09-05 |
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James pose la question : I need to prove a problem by induction regarding the Triangle Inequality. The problem is
abs(a1 + a2 +...+an) <= abs(a1) + abs(a2) +...+ abs(an). Victoria West lui répond. |
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A line parallel to y= 1/2x + 5 |
2008-09-03 |
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Michelle pose la question : Find the equation of a line parallel to y= 1/2x + 5 if the required line passes through ( 3,4) Penny Nom lui répond. |
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A roof angle |
2008-08-30 |
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carla pose la question : Use vectors to find the angle in the attached diagram Chris Fisher and Stephen La Rocque lui répond. |
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A cubic equation |
2008-08-25 |
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RAM pose la question : The following Cubic Eqn should have three roots - what are they?
x^3-27=0 Penny Nom lui répond. |
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Radii and Chords Create a Non-Right Triangle |
2008-08-22 |
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Beary pose la question : AOC is a diameter of circle O. Line AB is 12, and lines OA and OC (the radii) are 10. Find the length of line BO and chord BC. Janice Cotcher lui répond. |
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Simplifying Algebraic Expressions |
2008-08-22 |
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Jacky pose la question : x^2-y^2+4x+4y Penny Nom lui répond. |
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Trough Filling with Water |
2008-08-21 |
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lanny pose la question : a triangular trough is 10 feet long, 6 feet across the top, and 3 feet deep. if water flows at the rate of 12 cubic inches per minute, find how fast the surface is rising when the water is 6 inches deep. Janice Cotcher lui répond. |
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The game of 24 |
2008-08-20 |
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Tasha pose la question : I have four numbers a 6, a 6 a 5 and a 3, i can add subtract divide or multiply these numbers in anyway but i have to use all of them and call only use them once i have to come up with a total of 24 Penny Nom lui répond. |
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Factoring x^2 + 729 |
2008-08-19 |
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peter pose la question : hello I,am having trouble factorising a polynomial into polynomial factors
with real coefficients please can you help the polynomial is x^2+729 Harley Weston lui répond. |
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Solving for Shared Height of Two Right Triangles |
2008-08-17 |
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Heidi pose la question : find the height of a triangle, which can be split into two right triangles, but the base (50m) is not split equally in half. one end of the base is 40 degrees, while the other is 30 degrees. Janice Cotcher lui répond. |
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BEDMAS |
2008-08-12 |
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Rebecca pose la question : I have 3 questions.
1) I don't really understand BEDMAS.Im going in to the 6th grade and im
kind of nervis about it.?
2)When you're doing BEDMAS what does the small 3 or 2 above the
other numerals mean?
3)How would you answer this:5+2 x 9 - 9 x 12= ?? Janice Cotcher lui répond. |
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Arc-length and sector-angle |
2008-08-06 |
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Benson pose la question : If chord length, radius are given, How to find the sector angle and arc-length Janice Cotcher lui répond. |
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Find the product of 2^35 and 5^38 in sci. notation. |
2008-08-03 |
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Peter pose la question : I am preparing for a competition and a lot of the non-calculator problems are like find the product of 2^35 and 5^38 in sci. notation. How would you do that? Penny Nom lui répond. |
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The product of the digits of a four digit number |
2008-07-26 |
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Pete pose la question : I am a student preparing for a competition and this was one of the prep problems: The product of the digits of a four digit number is 6x5x4x3x2x1. how many such numbers are there with this property? Stephen La Rocque lui répond. |
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Proofs |
2008-07-26 |
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Taylor pose la question : when doing a proof, how do i figure out the steps in which i find the statements? i find the reasons pretty easily but i do not understand how to get the proving part. that would be great if you can help me! Thanks Victoria West lui répond. |
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Alpha level |
2008-07-23 |
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anonymous pose la question : What is the advantage of using an alpha level of .01 versus a level of .05, What is the disadvantage of using a smaller alpha level? Janice Cotcher lui répond. |
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The number of digits in a really big exponent |
2008-07-21 |
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Pete pose la question : how would you find the number of digits in a really big exponent without a calculator? Penny Nom lui répond. |
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Four Positive Integers |
2008-07-20 |
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william pose la question : let a, b, c and n be positive integers. If a+b+c=(19)(97) and a+n=b-n=c/n, compute the value of a. Janice Cotcher lui répond. |
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Number of factors |
2008-07-20 |
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pete pose la question : how do you find the number of factors in a really big number without using a factoring program or listing the out? Penny Nom lui répond. |
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solving four simultaneous equations |
2008-07-18 |
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Muhammad pose la question : -2B-2C+4E=1
A+B+C+D=0
-2B-2C-2D+E=0
B+C+4D-2E=0 Janice Cotcher lui répond. |
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Does the sequence 1 2 4 8 16 32 etc have a name? |
2008-07-17 |
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Richard pose la question : Just an idle thought really. Does the simple sequence 1 2 4 8 16 32 etc have a name? Victoria West lui répond. |
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Express as a function of x |
2008-07-14 |
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Rita pose la question : Express the area A of an isosceles right triangle as a function of x of one of the two equal sides.
NOTE: I always see the phrase "Express as a function of x" in math textbooks.
What exactly does that phrase mean?
I also have seen it written as "Express in terms of x." Penny Nom lui répond. |
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Profit as a percentage |
2008-07-08 |
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ANNORIS pose la question : Question from annoris, a student:
How to calculate percent of profits using step by step division formula.
I know how to get the profit.
Selling cost was $15.00
Cost amount was $10.00
Total profits its $ 5.00.
But i do not know how to get the percent because i dont know how to divide to well . Can you helppppppp me ? Penny Nom lui répond. |
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A net profit of 4% on a sales volume of $100 million |
2008-07-07 |
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Muriel pose la question : If a firm has a net profit of 4% on a sales volume of $100 million and the
company has instituted logistics programs that result in cost savings of
$1 million, what equivalent sales increase would be required to equal such
a cost savings?
What I do know is that the net profit % has increased from 4% to 5% and
the profit has gone from $4,000,000 to $5,000,000 but I have no idea what
the formula is to figure out how much sales would have to increase to
result in that same profit. Janice Cotcher lui répond. |
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Sum and product of the roots of a quadratic |
2008-07-03 |
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Gautam pose la question : If a and b are the roots of x^2+px+1=0 and c and d are the roots of
x^2+qx+1=0
prove that
(a-c)(b-c)(a+d)(b+d)=q^2-p^2
Regards
Gautam Harley Weston lui répond. |
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The sum of the digits of two-digit number is 9 |
2008-07-01 |
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Audrey pose la question : the sum of the digits of two-digit number is 9. if the digits are reversed, the new number if 63 greater than the original number. find the number. Penny Nom lui répond. |
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Slope and rate of change |
2008-06-23 |
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Lee pose la question : What is the difference between a slope and a rate of change? Stephen La Rocque lui répond. |
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111...111 * 2003 |
2008-06-23 |
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Peggy pose la question : Number a = 111...111 formed by 2003 1's. Find the sum of the digits of the number 2003 * a. Penny Nom lui répond. |
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The sum of the digits of a number |
2008-06-23 |
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Ben pose la question : Question: Using mathematical induction, prove that if the sum of the digits of a number is divisible by three, then the number itself is also divisible by 3. Penny Nom lui répond. |
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30% profit |
2008-06-19 |
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Julie pose la question : how do i calculate the price per person that will return a 30% profit on the sales revenue generated? Penny Nom lui répond. |
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Cows and chickens |
2008-06-16 |
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damebochie pose la question : I got this problem and want to write a system of equation for it:
Farmer Joe has cows and chickens on his farm. One day he count 76 legs and 24 heads. How many cows and how many chickens are on the farm? write a system of equations and solve.
I don't have any problem to solve it, but I just can;t see how I am going to write this system of equation.
Thank you so much for helping? Harley Weston lui répond. |
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The rate of change in the depth of the water |
2008-06-12 |
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Liz pose la question : A rectangular pool 50ft long and 30ft. wide has a depth of 8 ft. for the first 20 ft. for its length and a depth of 3 ft. on the last 20ft. of its length and tapers linearly for the 10 ft in the middle of its length. the pool is being filled with water at the rate of 3ftcubed/ min
at what rate is the depth of the water in the pool increasing after 15 hours? Harley Weston lui répond. |
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Guy wires for a tower |
2008-05-19 |
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larissa pose la question : a radio tower 500 feet high is located on the side of a hill ( the hill has an inclination to the horizontal of 5 degrees.) How long should two guy wires be if they are connected to the top of the tower and are secured at two points 100 feet directly above ( up the hill ) and directly below the base of the tower? Penny Nom lui répond. |
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Selling price |
2008-05-10 |
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Roxane pose la question : I'm trying to figure out the formula for the following, I have a product that
I want to receive a certain profit margin, but with this product I also have
to pay a percentage of commission to someone. I need to know how to
calculate my new selling price taking into account the markup percentage, but
I don't want my gross margin to be lowered. I have calculated the markup
percentage to get my new selling price with the commission, but it lowers
my profit margin once I pay the commission and I don't want it to do that. Penny Nom lui répond. |
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How many presses should be used? |
2008-05-04 |
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Sarah pose la question : Hi! I am in Calculus and this problem is on my study guide and i just cant figure it out!?
A printing company had eight presses, each of which can print 300 copies per hour. It costs $5.00 to set up each press for a run and 12.5+6n dollars to run n presses for an hour. How many presses should be used to print 6000 copies most profitably? Let h equal the number of hours used to print the 6000 copies. Harley Weston lui répond. |
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A bowl is the shape of a hemisphere |
2008-04-28 |
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josh pose la question : a bowl is the shape of a hemisphere with diameter 30 cm and water is poured into the bowl to a height h cm. how do i find the volume of the water in the bowl Harley Weston lui répond. |
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A volume of revolution |
2008-04-24 |
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Sabahat pose la question : Hi, i have a region enclosed by both axes, the line x=2 and the curve y=1/8 x2 + 2 is rotated about the y-axis to form a solid . How can i find the volume of this solid?. (Please note that y equation is read as y =1 over 8 times x square plus 2.) I will be really grateful if you answer this question. :) Harley Weston lui répond. |
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Why does -2^2 = -4 when -2 * -2 = 4? |
2008-04-22 |
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blaine pose la question : Why does -2^2 = -4 when -2 * -2 = 4? Penny Nom lui répond. |
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The three sides of a triangle |
2008-04-16 |
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Bridgett pose la question : The sum of the lengths of any 2 sides of a triangle must be greater than the third side. If the triangle has one side that is 11 CM, and the second side of the triangle is 4 cm less than twice the third side, what lengths do the 2nd and 3rd side have to be?
between 0000-00-00 and 9999-99-99 Stephen La Rocque lui répond. |
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How many bags of mulch? |
2008-04-07 |
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MJ pose la question : I have an area that is 35' X 50' and I want to cover it with 2" of mulch.
Do I take length X Width X depth? Bags of mulch are sold in 2 or 3 cubic feet per bag.....I just want to know how
to do the math. can you please send me the equation? Penny Nom lui répond. |
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A volume of revolution |
2008-04-04 |
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ted pose la question : Consider the region bounded by y=x^2 + 1, y=5-3x and y=5. Sketch and
shade the given region; then set up but dont evaluate teh integrals to find
the following:
a) The volume of the solid generated by rotating the region about the line
y=5
b) the volume of the solid generated by rotating the region about the y-axis Penny Nom lui répond. |
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How many bags of cement do I need |
2008-03-30 |
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Joe pose la question : How many bags of cement do I need if I want to extend my carport 6 inches all around?
The carport is 15ft. x 15ft. and the existing slab is 4 inches thick. Harley Weston lui répond. |
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The average rate of change |
2008-03-29 |
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Tom pose la question : For the function x/3x-1 find the average rate of change between the interval x=1 and x=5? Harley Weston lui répond. |
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A car tire full of concrete |
2008-03-27 |
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robert pose la question : I want to build a volleyball net support. I am using a car tire 24"odx16"id filled with concrete. how much will this weigh? thanks Penny Nom lui répond. |
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The product of the roots |
2008-03-19 |
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Rebecca pose la question : Determine the product of the roots of the equation
(x-1)(x-2) + (x-2)(x-5)=0 Penny Nom lui répond. |
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The sum and product of the roots of a quadratic |
2008-03-16 |
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Katelyn pose la question : Write the quadratic equation....
Sum of the roots = 16
Product of the roots = -80 Penny Nom lui répond. |
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A roll of paper |
2008-03-05 |
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Sheik pose la question : How I Convert My Roll Weight Into Meters?
Roll Width : 241mm
Thickness : 56gsm
Weight :81 Kg Harley Weston lui répond. |
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The profit was what percent of the cost? |
2008-02-29 |
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sierra pose la question : The profit was what percent of the cost?
Here is some more of that whole problem.
Selling Price-$26.60
Discount-$6.65
Sale Price after the Discount-$19.95
The Profit-$5.95 Penny Nom lui répond. |
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A proof in geometry |
2008-02-27 |
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Kimberly pose la question : I'm trying to write a proof for the following: If all altitudes are equal in an equilateral triangle then all sides are equal. Stephen La Rocque and Penny Nom lui répond. |
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What number has exactly 51 divisors? |
2008-02-26 |
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Lisa pose la question : What number has a Tau which equals 51? In other words, what number has exactly 51 divisors? It must be a square of some kind! Penny Nom, Victoria West and Harley Weston lui répond. |
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10 - 3 + 2 |
2008-02-21 |
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Amrit pose la question : what 10-3+2
is it 5 or 9 Penny Nom lui répond. |
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The slope intercept form of a line |
2008-02-17 |
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chris pose la question : find the slope and y intercept of the line (2x+4)-3y=11(x-1)
is this equation in slope point form. Penny Nom lui répond. |
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The length of the third side of a triangle |
2008-02-16 |
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mary pose la question : I have an angle of 72 degrees and each of the sides are 5' long. What is the distance from each of the ends of the 5 feet to form a triangle. Stephen La Rocque lui répond. |
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5x^2 - 45 |
2008-02-11 |
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Tiana pose la question : factor:
5x^2 - 45 Stephen La Rocque lui répond. |
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What percent profit is this? |
2008-02-07 |
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Vanessa pose la question : Mrs Henderson buys a chair for $215.00 and later sell the chair for $336.00 what percent
profit is this? Penny Nom lui répond. |
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Total profit |
2008-02-03 |
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Rhonda pose la question : I help to manage a concession stand. We sell a variety of items. Some have a profit of 60%, some 80%, etc. We have done nothing scientific to choose our prices. We just try to stay in the ballpark of schools around us. Our administrator wants to pay those that run the concession stand a percent of what is in the cash box after start-up money is taken out. We have some gathered some data (not much) on how many of each item we sell and can certainly calculate percent profit. Is the profit for the entire concession stand a weighed average? I'm thinking (% profit on candy)(number candy sold) + (percent profit nachos)(number nachos sold) + (percent profit pop)(number pop sold), etc. Will this work? Does the AMOUNT of profit for these different items need to be figured-in? Hmmm. . . Victoria West and Harley Weston lui répond. |
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Sum and difference of cubes |
2008-01-30 |
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Amanda pose la question : It has been a really long time since I was in Algebra and I can't remember how to factor cubes such as x^3 +81 or subtracting/adding fractions with variables such as [1/(x+h)+2]-[1/x+2]. Please help!!! Penny Nom lui répond. |
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The volume of a tank |
2008-01-27 |
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Fred pose la question : A cubic tank holds 1,000 kilograms of water what are the dimensions of the tank in meters? Harley Weston lui répond. |
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Find the slope of the line with equation 7-3y=2x |
2008-01-23 |
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nell pose la question : Find the slope of the line with equation 7-3y=2x Stephen La Rocque lui répond. |
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Out of school applications of Pythagoras Theorem |
2008-01-23 |
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Laura pose la question : Hi,
I am currently working on a math summative in which I have to choose a real life subject and relate it back to the material in my grade 12 math class. I find the history and discovery behind the Pythagorean Theorem and Identity very interesting, but I have yet to find a real-life application of the equations. Yes, I know they are used for finding distances, heights etc., but realistically, how many people actually use it in those situations? Very few. I was hoping for a new application. Is the pythagorean theorem (sin^2x + cos^2x = 1) even applicable? Thank you,
Laura Harley Weston lui répond. |
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A parallelogram and a rhombus |
2008-01-22 |
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miguel pose la question : i have a problem proving a parallelogram a rhombus.. if a diagonal of a parallelogram bisects an angle
of the parallelogram , then its a rhombus
prove Stephen La Rocque and Walter Whiteley lui répond. |
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1/2, 1/2, 3/8, 1/4, 5/32, 3/32, 7/128 |
2008-01-22 |
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Neil pose la question : Find the next two terms in the following number sequence
1/2, 1/2, 3/8, 1/4, 5/32, 3/32, 7/128
Find a general rule for the nth term of the sequence Penny Nom lui répond. |
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The equation of a line |
2008-01-20 |
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Sara pose la question : The question is:
Write the equation of a line that is parallel to y=3x-2 through the point (-5,9).
I think the correct equation for this is y=3x+24.
But I have to write it in standard form, and I can't seem to figure out how to do that. Please answer soon! Thanks! Stephen La Rocque and Penny Nom lui répond. |
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The line through (-22 ;-1) and (-23, -2) |
2008-01-20 |
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Zachery pose la question : i have a slope that equals 1/1 and my coordinates are (-22;-1) and (-23;-2) and i am trying to change it into the equation y=mx+b and the farthest that i've gotten is y=1x_ (i can not find out how to find b.) So i was wondering if you could help me find out what b is because i have got no clue!!!!! Penny Nom lui répond. |
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The game of 24 |
2008-01-17 |
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Raina pose la question : I have four numbers 3 3 9 5 that need to equal 24 using addition subtraction multipliction and division and I'm so stuck. Chris Langdon, Stephen La Rocque and Claude Tardif lui répond. |
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The angles of a triangle given the three sides |
2008-01-17 |
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Lucy pose la question : Is there a way to find the angles of a triangle just by knowing the lengths of it's sides?
It seems like the would be a relationship between the two, but I'm not sure. Stephen La Rocque and Harley Weston lui répond. |
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Explaining the factoring for the difference of cubes |
2008-01-16 |
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Bill pose la question : A student asked me where did the "difference of cubes" and "sum of cubes" come from. I did not have an answer for her. She is very bright and understands how they work but wanted to know where they derived from. Any help you can offer would be great. Thanks Stephen La Rocque lui répond. |
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Two solutions using the law of sines |
2008-01-14 |
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Kate pose la question : I am working on the Law of Sines and I have a problem that says: Find a value for b so that the triangle has 2 solutions.
I am given that A = 36 degrees and a = 5. Now, I learned that for a triangle to have 2 solutions, h < a < b.
BUT...my answer key says the answer is: 5 < b < 5/sin 36. I can't figure out how to make this fit with h < a < b. Harley Weston lui répond. |
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How far is the jet from the lighthouse? |
2008-01-07 |
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Natalie pose la question : Question: A ship spots a lighthouse that is 53m high, at an angle of elevation of 7 degrees that is directly north of the ship. The same ship spots a jet travelling N62E at an altitude of 1500m with an angle of elevation of 15 degrees. How far is the jet from the lighthouse?
Natalie Harley Weston lui répond. |
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The standard normal distribution |
2007-12-29 |
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GEORGE pose la question : Statistics texts state that in a normal distribution, 1 standard deviation covers 68%, 2SD 95% 3SD 99.7%. However, on looking at the tables for normal curve areas, the percentage for a z value of 1 is 84.13. 68 % of values are covered at a z value of 0.47. The discrepancies exist even for other values but are smaller. So why is the rule of thumb so different from the Table for Normal Curve areas? Harley Weston lui répond. |
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Profit percentage (markup and margin) |
2007-12-18 |
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Laura pose la question : If my husband says he sold $11,000 worth of tools and made $1400 on the deal, what is the percent of profit? Stephen La Rocque lui répond. |
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How many houses must they paint? |
2007-12-12 |
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Natalie pose la question : The question is: Four boys work together,painting houses for the summer.For each house they paint they get 256 pounds.
If they work for four months of the summer and their expenses are 152
pounds per a month, how many houses must they paint for each of them
to have one thousand pounds at the end of the summer? Penny Nom lui répond. |
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System of equations |
2007-12-06 |
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Jenn pose la question : change the equation,x-y=4 to form y=mx+b
the solution to the system of equations y=2x and y=-x+3 is Stephen La Rocque lui répond. |
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Chicken and goat feet |
2007-12-05 |
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Kim pose la question : Old McDonald raises goats and chickens. The animals have a total of
100 heads adn 360 feet. How many goats and how many chickens does Mr.
McDonald have? Stephen La Rocque and Penny Nom lui répond. |
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(32-2 x 5) divided by 2 + 8 |
2007-11-28 |
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Kim pose la question : Solve
(32-2 x 5) divided by 2 + 8 Leeanne Boehm lui répond. |
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A curve sketch |
2007-11-22 |
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Ahson pose la question : Find critical points, determine the monotonicity and concavity and sketch
a graph of f(x) with any local maximum, local minimum and inflection
points labeled:
1. f(x) = x^4 - x^3 - 3x^2 + 1 Harley Weston lui répond. |
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Bundles of wood |
2007-11-19 |
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Darcy pose la question : When you purchase a "bundle" of wood at the store, it is marked .75 cubic feet. What is the formula for figuring out that measurement for cubic feet and what fraction of a true cord of wood (128 cubic feet) is it. I would appreciate the formula so I can build a spreadsheet to help my secretaries and myself be in compliance to the law when selling firewood. Thanks. Harley Weston lui répond. |
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Confidence level |
2007-11-19 |
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Fara pose la question : It is common for public opinion polls to have a " confidence level" of 95%, meaning
that there is a 0.95 probability that the poll results are accurate within the claimed margins of error.
If six different organizations conduct independent polls, what is the probability that all
six of them are accurate within the claimed margins of error? Does the results suggest that
with a confidence level of 95%, we can expect that almost all polls will be within the claimed
margin of error? Harley Weston lui répond. |
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Find the radius of a circle given the center and a point on the circle |
2007-11-18 |
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Raymund pose la question : Find the radius if the center is at (0, -5) and one point on the circle is (2,3) Stephen La Rocque lui répond. |
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Expand (a^4 - b^4) |
2007-11-17 |
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Saif pose la question : how would you expand (a^4 - b^4) ??? Stephen La Rocque and Victoria West lui répond. |
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A geometric proof |
2007-11-16 |
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Julie pose la question : Prove that tangents to a circle at the endpoints of a diameter are parallel. State what is given, what is to be proved, and your plan of proof. Then write a two-column proof. Walter Whiteley lui répond. |
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Why do they use the letter b in y=mx+b? |
2007-11-15 |
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virginia pose la question : why do they use the letter b in y=mx+b?
im asking this because my math teacher said he will give extra points to anyone who finds this out first
and i was hoping you guys would be the ones who could help. Penny Nom lui répond. |
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Maximize his profit |
2007-11-12 |
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apoorva pose la question : 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. |
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6 consecutive multiples of 6 |
2007-11-11 |
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jeff pose la question : find 6 consecutive multiples of 6 whose sum is the least common multiple of 13 and 18 Penny Nom lui répond. |
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Questions of the Month |
2007-11-01 |
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Judith pose la question : Where would I find comprehensive questions, that cover the majority of skills in a unit such as number sense, to use as "Questions of the Month"? Victoria West lui répond. |
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The rate of change of the concentration of a solution |
2007-10-30 |
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Nicholas pose la question : A barrel initially has two kg of salt dissolved in twenty liters of water. If water flows in the rate of 0.4 liters per minute and the well-mixed salt water solution flow out at the same rate, how much salt is present after 8 minutes?
I tried working backwards given the answer but I can't seen to get their answer of ~1.7kg. Any help would be great! Thanks Harley Weston lui répond. |
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Two mirrors |
2007-10-24 |
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Peter pose la question : The reflecting surfaces of two intersecting flat mirrors are at an angle θ (0° < θ < 90°). For a light ray that strikes the horizontal mirror, show that the emerging ray will intersect the incident ray at an angle β = 180° – 2θ. Stephen La Rocque lui répond. |
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Turn 81 into the power of three |
2007-10-22 |
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Victoria pose la question : I do not understand how to turn 81 into the power of three. Penny Nom lui répond. |
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Maximize profit |
2007-10-22 |
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Dina pose la question : A meat market purchases steak from a local meat packinghouse. The meat is purchased on Monday at a price of $2 per pound, and the meat market sells the steak for $3 per pound. Any steak left over at the end of the week is sold to a local Zoo for $0.50 per pound. The demand for steak and the probabilities of occurrence are as follows:
Demand Probability
20 10%
21 10%
22 15%
23 20%
24 20%
25 15%
26 10%
Determine the amount of stock to maximize the profit. Draw the graph and explain. Penny Nom lui répond. |
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The rate of change of the area of a triangle |
2007-10-22 |
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Ahlee pose la question : So my question is:
The included angle of the two sides of a constant equal length s of an isosceles triangle is ϑ.
(a) Show that the area of the triangle is given by A=1/2s^2 sinϑ
(b) If ϑ is increasing at the rate of 1/2 radian per minute, find the rate of change of the area when ϑ=pi/6 and ϑ=pi/3.
(c) Explain why the rate of change of the area of a triangle is not constant even though dϑ/dt is constant Penny Nom lui répond. |
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Order of operations |
2007-10-17 |
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Devon pose la question : What function precedes the other? ie; 18 - 4 x2 = Penny Nom lui répond. |
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Four triangles in a square |
2007-10-15 |
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Kristina pose la question : A square with side lengths of 6 cm is divided into 3 right triangles and a larger isosceles triangle. If the three right triangles have equal area, find the exact area of the isosceles triangle. Stephen La Rocque lui répond. |
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15 divided by 5a |
2007-10-12 |
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Susan pose la question : Is "5a" considered an expression to be solved first, or do you simply go in PEMDAS order with the 15 divided by 5 in the following problem: Evaluate when a = 2 15 divided by 5a Penny Nom lui répond. |
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How much water is in a hose? |
2007-10-12 |
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Bryan pose la question : I need to know how much water (gal) is in a hose thats 100' long by 5" in dia.
Thanks Stephen La Rocque lui répond. |
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The average rate of change of a function |
2007-10-11 |
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vern pose la question : Find the average rate of change of the function over the given interval. Compare this average rate of change with the instantaneous rates of change at the endpoints of the interval. f(X)=sinX for the inverval [0,pi/6]? Harley Weston lui répond. |
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Substitution method |
2007-10-11 |
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Kevin pose la question : 3xx+2y=-36-y=11 Stephen La Rocque lui répond. |
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Area of a quadrilateral |
2007-10-10 |
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Courtney pose la question : how would i find the area of a quadrilateral..
the sides are a (/) is 6cm, b (—) is 9 cm, and c (\) is 7 cm..
the angle between a and b is 140 degrees and b and c is 115 degrees.. Stephen La Rocque lui répond. |
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Simplifying algebraic expressions |
2007-10-09 |
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Sakeena pose la question : (2^2*3)^x+1/2^2x*3x Stephen La Rocque lui répond. |
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Solving four simultaneous equations (system of four linear equations) |
2007-10-07 |
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Johan pose la question : I need some help in solving this question
x + 2y - 3z + 4w = 12
2x + 2y - 2z + 3w = 10
0 + y + z + 0 = -1
x - y + z - 2w = -4 Stephen La Rocque lui répond. |
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Solving arithmetic problems in the right order (BEDMAS) |
2007-10-05 |
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Kim pose la question : 3+4x2-(10 divided by 5)= what? Penny Nom lui répond. |
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Maximizing profits II |
2007-10-05 |
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a student pose la question : Suppose there are three firms with the same demand function. The function is Q=1000-40P. Each firm also a a cost function.
Firm 1: 4000+5Q,
Firm 2: 3000+5Q,
Firm 3: 3000+7Q.
What price should each firm charge if it wants to maximize profits. Harley Weston lui répond. |
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Maximizing profit |
2007-10-05 |
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a student pose la question : Use the following equation to demonstrate how a firm that produces at MR=MC can also maximize its total profit. The equations to use are
P=170-5Q
TC=40+50Q+5Q^2 Harley Weston lui répond. |
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y squared over 3 times 8 over y |
2007-09-30 |
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John pose la question : y squared over 3 times 8 over y Stephen La Rocque lui répond. |
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The area of a roof |
2007-09-27 |
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RANDY pose la question : I have an area of roof. It's in a sort of triangle.
it's 25' across the top
30' at each edge
86' across the bottom Stephen La Rocque lui répond. |
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The game of 24 |
2007-09-27 |
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Amanda pose la question : I'm really stumped on a 24 math game question from math class. The numbers are 7,11,17,and 20. Help?? Claude Tardif lui répond. |
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Cubic meters, square feet and office space |
2007-09-25 |
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Kathryn pose la question : Can someone please help and let me know how do you convert 11 cubic meters into square footage? Steve La Rocque and Harley Weston lui répond. |
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Prove that any two consecutive integers are relativley prime. |
2007-09-18 |
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Michael pose la question : Im not very good at proofs and I was wandering if you would be able to help me with the following question:
Prove that any two consecutive integers is relativley prime.
Thanks a million. Penny Nom lui répond. |
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A 5 by 5 checkerboard |
2007-09-17 |
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Darren pose la question : Hi, I'm Darren and i have some questions to ask you about this problem:
In a 5 by 5 checkerboard : how many 2 by 2 squares are there,
what other sizes of squares do you need to count and how many of of each size of squares
can you find; how many squares did you find in all Victoria West lui répond. |
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Two equations in two unknowns |
2007-09-14 |
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CAMEILA pose la question : NEED T0 SOLVE THIS EQUATION
Y = -2X + 6
Y + 6 = 2x Stephen La Rocque lui répond. |
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The area of half a circle |
2007-09-14 |
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Heather pose la question : We need the formula for area of half circle please explain where each number comes from. Penny Nom lui répond. |
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The slope of a line |
2007-09-06 |
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Danielle pose la question : Hello. I need some help with this: i am supposed to find the equation of a line with a point
(2/3,5) and (-5/6,-4) the answer in the book says y=6x+1. My question is how did they get
for the slope? Penny Nom lui répond. |
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How many two digit numbers contain at least one 7? |
2007-09-06 |
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Janet pose la question : How many two digit numbers contain at least one number seven? Penny Nom lui répond. |
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Fractions, ratios and percentages all mixed together |
2007-08-29 |
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Charon pose la question : Example: x : 1/4% :: 9 3/5 : 1/200 Stephen La Rocque lui répond. |
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Two-column proof for a circle geometry problem |
2007-08-24 |
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Kendra pose la question : i have to prove that tangents to a circle at the endpoints of a diatmeter are parallel by stating whats given, whats to prove and a plane, then write a two column proof i dont understand this Stephen La Rocque lui répond. |
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A geometry problem |
2007-08-20 |
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samhita pose la question : ABC is a triangle. Let D be a point on side BC produced beyond B such that BD=BA. Let M be the mid-point of AC. The bisector of angle ABC meets DM at P. Prove that angle BAP=angle ACB. Chris Fisher lui répond. |
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The length of the third side of a triangle |
2007-08-15 |
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Brooklyn pose la question : What is the equation to find the length of the third side of a triangle if you have the length of A, B, and the angles(s)? Stephen La Rocque lui répond. |
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Twenty dining tables |
2007-08-13 |
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priya pose la question : Utkarsh bought 20 dining tables for Rs 120000 and sold these at a profit equal to the S.P of 4 dining tables.Find the S.P of one dining table.(give the answer in statements) Stephen La Rocque lui répond. |
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Induction - divisibility |
2007-08-04 |
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Jerry pose la question : How would you prove that for any positive integer n, the value of the expression 3^(2n+2) - 8n -9 is divisible by 64. Chris Fisher and Penny Nom lui répond. |
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What fraction of the letters of the alphabet is each word? |
2007-08-02 |
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Clayton pose la question : How do I figure this out, the math question has the answers but I have no idea how to get it.
my Mom can't figure it out either.
What fraction of the letters of the alphabet are each word
Man = 3/26
Glasses = 7/26
Integrity = 1/4
computer = 2/9 Paul Betts and Harley Weston lui répond. |
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The height of a pole |
2007-08-02 |
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lalaine pose la question : Hi, this is my problem..
From a point 50.2 m to the pole, a student measured the angle of elevation to the top of the pole to be 32°. Find the height of the pole if the student's height from his feet to his eyes is about 4 ft. Penny Nom lui répond. |
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Multiplcation of two negative numbers |
2007-07-26 |
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Brett pose la question : Someone asked a question about multiplication and division of two negative numbers yielding a positive result here:
http://mathcentral.uregina.ca/qq/database/QQ.09.99/butler1.html I was not fully happy with the explanation b/c I want to give me daughter a real-world example and I can't seem to find one.
The following illustrates why multiplying negative numbers has become difficult to explain:
2 X 2 = 4
----(-4)---(-2)---0---2---4
In this example we start with 2 and then want 2 more of them.
When we move across the number line from 2 to our answer, which is four, we have moved only 2 units to the right.
-2 X -2 = 4
----(-4)---(-2)---0---2---4
In this example we start with -2 and then want -2 more of them.
When we move across the number line from -2 to our answer, which is four, we have moved 6 units to the right.
How can the phenomenon of multiplying two negative numbers being more powerful than multiplying two positive numbers be explained?
-Brett Stephen La Rocque and Harley Weston lui répond. |
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Simplifying an algebraic fraction expression |
2007-07-25 |
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Jessica pose la question : How do I simplify b/(b2-25) + 5/(b+5) - 6/b? Stephen La Rocque lui répond. |
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Angle of depression |
2007-07-23 |
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joyce pose la question : hello,
here is my problem......
As you stand on a bridge w/c is 100 ft. above the water
you are looking @ an approaching barge.
If the A of top of the front of the bridge is 29.04 degrees
and the angle of depression of the rear is 17.36 degrees .
Find the length of the barge? Harley Weston lui répond. |
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What fraction of the company does Mary own? |
2007-07-18 |
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Bridget 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? Stephen La Rocque lui répond. |
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Angle of depression (declination) between sailboat observations |
2007-07-18 |
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Joyce pose la question : From a cliff 150 ft above a lake, we see a boat sailing directly towards us.
The angle of depression of the boat is seen to be 5 degrees and 7 inches and
11 degrees and 18 inches. Find the distance sailed between observations. Stephen La Rocque lui répond. |
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Angle of inclination from the horizontal |
2007-07-18 |
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Joyce pose la question : In flying upward for 1260 yards along a straight inclined path airplane rises
156 yards. Find the climbing angle
( the angle of inclination from the horizontal)
Thank you in advance Stephen La Rocque lui répond. |
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Calculating the area (acreage) of a four sided lot |
2007-07-18 |
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A property owner pose la question : I have a real estate property and the lot size is something I need to find out. I know the lengths of the four sides, but it isn't a rectangle, it is an odd shape. How do I find the acreage? Stephen La Rocque lui répond. |
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Height of a tower from two observations |
2007-07-16 |
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joyce pose la question : An observer wishes to determine the height of a tower. He takes sight @
the top of the tower from A & B w/c are 5oft. apart @
the elevation on a direct line w/ the tower.
The vertical angle @ point A is 30 degrees & the point B is 40 degrees.
What is the height of the tower?
Find the value of x in angle tangent 40 degrees and 30 degrees?
Show the solution of the value of x? Stephen La Rocque lui répond. |
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Height of an antenna (angle of elevation) |
2007-07-16 |
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Fhay pose la question : An antenna stands on the edge of the top of a 52 story building from a point 320 ft. from the base of the building, the angle of elevation to the top of the antenna is 64 degrees in each story is 12 ft. high. Find the height of the antenna Stephen La Rocque lui répond. |
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The two towers (angles of elevation trigonometry) |
2007-07-14 |
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joyce pose la question : The angle of elevation of tower B from the top of tower A is 28 degrees
and the angle of elevation of the top of tower A from the base is 46 degrees
Find the height of tower A if tower B is 120 m high? Stephen La Rocque lui répond. |
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Proving a quadrilateral is a rectangle |
2007-07-14 |
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Sonja pose la question : I was having this discussion with another teacher and we need a third opinion. When you are trying to prove a quadrilateral is a rectangle which method should you use:
- Prove the shape is a parallelogram by doing slope 4 times by stating that parallel lines have equal slopes. Then proving a right angle by stating that perpendicular lines have negative reciprocal slopes.
- Doing the slope 4 times and stating that the shape is a rectangle because opposite sides are parallel because of equal slopes and it contains a right angle because of negative reciprocal slopes.
I guess the real question is do you have to first state that the shape is a parallelogram? Stephen La Rocque lui répond. |
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Any regular polygon inscribed in a circle |
2007-07-12 |
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DJ pose la question : Circle with r=12" is inscribed in a regular octagon. What is the length of each octagon segment?
Note: Our answer works for any regular polygon inscribed in any circle. Stephen La Rocque lui répond. |
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Grams of vodka |
2007-07-10 |
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Andrew pose la question : milliliters to grams..vodka 80 proof? Stephen La Rocque lui répond. |
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Derivative of a Function |
2007-07-09 |
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Bob pose la question : What is the derivative of the function a sub n = [n/(n+1)]^n ? Stephen La Rocque lui répond. |
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Proof that any side of a triangle is less than half the perimeter. |
2007-07-07 |
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Omkar pose la question : Any side of a triangle is smaller than half of its perimeter, prove this in short ? Stephen La Rocque lui répond. |
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Splitting the profits unequally |
2007-06-27 |
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Maci pose la question : We recently hosted a fundraiser.
Not everyone will receive a whole share of the profits
because they did not participate the entire time.
Several will receive only 1/2 or 1/3 share.
How do I divide the profits? Stephen La Rocque lui répond. |
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Selling price and revenue |
2007-06-24 |
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nick pose la question : hello, this is my first time asking for help from this website in which by the way, i think is great for everyone. My question is as follows... the relationship between the selling price of a sleeping bag, s dollars, and the revenue at that selling price, r(s) dollars is represented by the function: r(s)= -10s^2+1500s
evaluate, interpret, and compare: a) r(29.95) Stephen La Rocque and Penny Nom lui répond. |
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Simplifying complex denominators |
2007-06-21 |
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Krys pose la question : How do I simplify completely?
((4+i ) / (3+i )) - ((2-i ) / (5-i )) Stephen La Rocque lui répond. |
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Simplifying a quartic rational expression using long division |
2007-06-14 |
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Megan pose la question : x+2/12x^4+17x^3+0x^2+8x-40= Stephen La Rocque and Penny Nom lui répond. |
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Angles of depression |
2007-06-13 |
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Phonda pose la question : The pilot of a small private plane can look forward and see the control tower for a small airstrip. Beyond that is a large factory that is 3 milies from the airstrip. The angles of depression are 12.5 degrees and 4.8 degrees respectively.
Find the airplane's altitude, to the nearest ten feet. Stephen La Rocque lui répond. |
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The area of a quadrilateral |
2007-06-10 |
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Lucy pose la question : Calculate the area of the quadrilateral ABCD.
AB= 4.1cm, BC = 7.6cm, AD= 5.4 cm, CD= ?
Angle ABC = 117, Angle ADC = 62.
Give your answer correct to 3 significant figures. Stephen La Rocque and Penny Nom lui répond. |
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The law of sines |
2007-06-09 |
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Felicia pose la question : A parallelogram has one side that is 12.0 cm and one angle that is 65°. The shorter diagonal is 25.0 cm. To the nearest tenth of a centimetre, how long is the other side of the parallelogram? Use the sine law. Penny Nom lui répond. |
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Rate of change of distance between the clock hands |
2007-06-05 |
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Jonathan pose la question : A certain Clock has a minute hand with a length of 4 inches long and an hour hand with a length of 3 inches long. How fast is the distance between tips of these hands changing at 9:00? Stephen La Rocque lui répond. |
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What happens when you have zero's on both sides? |
2007-06-05 |
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Lily pose la question : On the substitution method what happens when you have zero's on both
sides of the equation? Is that considered no solution or infinitely many? Stephen La Rocque and Penny Nom lui répond. |
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Area of an isosceles triangle |
2007-06-01 |
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Josh pose la question : In a previous question answered by Sue regarding the area of a regular polygon you gave a formula for the area of an isosceles. My question is how did you get this formula? Can you please explain to mean the process that you used to get that formula?
Thanks Stephen La Rocque lui répond. |
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The intersection of two planes |
2007-05-31 |
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Sarim pose la question : How to find a intersection of two planes? Penny Nom lui répond. |
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Fractions, decimals and profit |
2007-05-29 |
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fatima pose la question : how can i change a fraction into a decimal and how do i change a
decimal into a fraction................
anther question please what does making a profit have
to do with percentage change!!!!!! Penny Nom lui répond. |
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System of equations |
2007-05-24 |
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Chris pose la question : Find all real solutions (x,y,z,w) of the system of equations:
2y= x + x/17, 2z= y + y/17, 2w = z + z/17, 2x= w + w/17 Penny Nom lui répond. |
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Find the sample size needed |
2007-05-13 |
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Mini pose la question : Find the sample size needed to be 98% confident thata marketing survey on the proportion of shoppers who use the internet for holiday shopping is accurate within a margin of error of 0.02. Assume that the conditions for a binomial distribution are met, and that a current estimate for a sample proportion does not exist. Penny Nom lui répond. |
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Find the equation of a line passing through two given points |
2007-05-12 |
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Kenzie pose la question : I am having problems solving an equation of the line passing through (-2,4) and (6,0) Penny Nom and Stephen La Rocque lui répond. |
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Angle of Elevation |
2007-05-10 |
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Micky pose la question : Two Buildings are on opposite sides of a street 40 feet wide.
The taller of the two buildings is 580 feet tall. The angle of depression
from the top of the tallest building to the shorter building across the
street is 57 degrees. Find the height of the shorter building. Stephen La Rocque lui répond. |
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Are proofs important in geometry? |
2007-05-07 |
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BJ pose la question : Are proofs very important to know how to do?
My daughter has been in Geometry & the teacher skipped proofs. Penny Nom lui répond. |
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What is the square root of 729 to the third power? |
2007-04-25 |
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Tori pose la question : What is the square root of 729 to the third power? Penny Nom lui répond. |
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The size of a freezer |
2007-04-23 |
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Jacqui pose la question : How many can packages can fit? I have a freezer that is 7cf. But
it contains a little tray component. The freezer measurements without the
tray is(bear with me, I'm not good with LxWxD) 23 across x 16 W x 25
deep (I'm assuming depth) and the tray is 8 across x 16 w x 15 D. We are
trying to see how many 9 L x 6 W x 3.5 D packages can fit in the freezer.
Please help me. I'm getting app. 60. I need 84 to be able to fit. Penny Nom lui répond. |
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Ax + By = C |
2007-04-18 |
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Diana pose la question : find an equation in general form Ax + By = C with the following properties passing through points (a,b) and (2a, 2b) Penny Nom lui répond. |
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The area of a heptagon |
2007-04-14 |
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Chantel pose la question : Would you be able to tell me the formula to work out the area of a
heptagon? thank you. Stephen La Rocque lui répond. |
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The angle of depression |
2007-04-14 |
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Mary-Beth pose la question : Two towers are 30 m apart. From the 15th floor, 40 m up, find the angle of depression to the base of the taller tower? I think the answer is 53, but the answer book says 37. Penny Nom lui répond. |
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Intersection of a line and a circle |
2007-04-12 |
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gaby pose la question : The sum of two numbers is 9. The sum of the squares of the two numbers is 41. Find the numbers. Steve La Rocque and Melanie Tyrer lui répond. |
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A volume of revolution |
2007-04-08 |
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christina pose la question : find the volume of the solid formed when region bounded by y=x/3, y=2
and the y-axis. it is revolved about the x-axis.
the assignment was to use both the washer method and the shell method
but when i solved for the volume, i got different answers.
i think my shell method is wrong because i know i'm having difficulties
with using "dy" instead of "dx"
here's my work so far: Penny Nom lui répond. |
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3 divided by 3 to it's fifth root |
2007-04-06 |
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Annie pose la question : How do I transform the equation 3 divided by 3 to it's fifth root to simple radical form
(getting the radical out of the denominator)? Penny Nom lui répond. |
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How much did it originally cost? |
2007-04-04 |
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Megan pose la question : My question is simple:
"-Jim is able to sell a hand-carved statue for $650 which was a 35% profit over his cost. How much did ie originally cost?"
I don't even know where to start could you help? Penny Nom lui répond. |
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Game of 24 |
2007-04-04 |
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teri pose la question : How do you find the answer of 24 by using 12,24,7 and 2 only once. Stephen La Rocque lui répond. |
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Using the "difference of squares" formula how do I compute 27 * 33? |
2007-04-02 |
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Sarah pose la question : Using the "difference of squares" formula how do I compute 27 * 33? Penny Nom lui répond. |
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Is the inverse of a function always a function? |
2007-03-29 |
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San pose la question : Is the inverse of a function always a function? Please justify. Thank You! Penny Nom lui répond. |
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Factoring a trinomial |
2007-03-27 |
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Kim pose la question : Hi, could you please help me solve this.
3x(squared) +20x - 7 Leeanne Boehm lui répond. |
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The distance between two fire towers |
2007-03-23 |
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tony pose la question : Two fire towers are 30km apart, tower A is due west of tower B. A fire is spotted from the towers, and the bearing from A and B are N76degreesE and N56degreesW, respectively. Find the distance from the fire to the straight line connecting tower A to tower B. Stephen La Rocque lui répond. |
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Graphing a line |
2007-03-23 |
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mitchell pose la question : Graph each equation.
y = 2x + 4 Jaymi Peterson and Haley Ess lui répond. |
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The law of cosines |
2007-03-23 |
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chetna pose la question : Q 1) In triangle LMN, l=7, m=5 , n=4. find ANGLE N.
After applying the rule and substituting values i'm getting
Cos n= 58/40. Is there something wrong. The answer at the back of the book is 34 degrees. Penny Nom lui répond. |
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Angles of depression |
2007-03-21 |
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romaine pose la question : a woman of height 1.4m standing on top of a building of height 34.6m veiws a tree some distance away.
she observes that the angle of depression of the bottom of the tree is 35 degrees, and the angle of depression of the top
of the tree is 29 degrees. assume that the building and the tree is on level ground.
(a) calculate the distance of the woman from the top of the tree measured along her line of sight.
(b) determine the height of the tree. Stephen La Rocque lui répond. |
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Angle of elevation |
2007-03-13 |
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Joslyn pose la question : A ship at sea sights a 12m high lighthouse on a cliff which is 80m above sea level.
If the angle of elevation to the top of the lighthouse is 27 degrees, calculate the distance from the ship to the shore. Haley Ess lui répond. |
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What is pi? |
2007-03-09 |
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Billy pose la question : What is pi? Jaymi Peterson and Sara Ulmer lui répond. |
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At what rate is the area of the triangle changing? |
2007-02-24 |
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mac pose la question : two sticks 3.5 feet long are hinged together and are stood up to form an isosceles triangle with the floor. The sticks slide apart, and at the moment when the triangle is equilateral, the angle is increasing at the rate of 1/3 radian/sec. At what rate is the area of the triangle increasing or decreasing at that moment? Mac Penny Nom lui répond. |
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Find the area of the triangle |
2007-02-20 |
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Christina pose la question : Graph the function f(X)= x+1/x-1 and graph the tangent line to the function at the points A:(2,3) and B:(-1,0). The point of intersection of the two tangent lines is C. Find the area of the triangle ABC. Stephen La Rocque lui répond. |
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Surface Area of a cone |
2007-02-19 |
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Cari pose la question : I am doing a math project. I am very confused on how to find the surface area of a cone. I have looked at other equtions but i still don't understand. How do you find the surface area of a cone that has a 15cm length and a 3.5cm radius? Penny Nom lui répond. |
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Factoring polynomials |
2007-02-14 |
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Joe pose la question : I am in the eighth grade, and we are learning the equivalent of Algebra 2. I have no ides how to factor (x-2)(x^2-1)-6x-6 You help is most aprreciated. Thank you! Joe Stephen La Rocque lui répond. |
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The surface area of a dome |
2007-02-11 |
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chris pose la question : I need to figure the surface area of a dome which is 96" across and 48" tall. Could you help please? Thanks! Penny Nom and Melanie Tyrer lui répond. |
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Large exponents |
2007-02-09 |
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Nick pose la question : I am trying to figure out an extremely large number. It relates to the estimated number of bacterial divisions in 12775 generations of bacteria. The problem I need to solve is: 2^12775 or 2 to the power of 12,775. Stephen La Rocque and Penny Nom lui répond. |
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The area for a pentagon |
2007-02-09 |
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nicole pose la question : how do you find the area for a pentagon Stephen La Rocque lui répond. |
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The capacity of a tank |
2007-02-08 |
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lorn pose la question : what is the capacity of a tank height is 110 feet diameter is 24 feet Brennan Yaremko lui répond. |
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An even positive integer cubed minus four times the number |
2007-02-07 |
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Rachael pose la question : I can't figure out the proof or the method to get the proof for this question: any even positive integer cubed minus four times the number is divisible by 48 Haley Ess and Penny Nom lui répond. |
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How to calculate margin of profit???? |
2007-02-03 |
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A student pose la question : If cost price is Rs. 100/- and our selling price is 139/-. I want to know the gross profit & how much margin in this???? Penny Nom lui répond. |
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The volume of a cone |
2007-01-31 |
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ajay pose la question : WHY VOLUME OF CONE IS ONE THIRD OF THE VOLUME OF CYLINDER? Penny Nom lui répond. |
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The height of an isosceles triangle |
2007-01-27 |
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Brendan pose la question : I need to find the height of an isosceles triangle whose angles are 52, 52 and 76 degrees. The base is 100, and the two equal sides are unknown. How would I go about this? Stephen La Rocque lui répond. |
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The area of a ellipse |
2007-01-25 |
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Ranjit pose la question : I have a task in which i have to find the area of a ellipse. i find this difficult because i have only been provided with the perimeter, which is 1000m. Chris Fisher lui répond. |
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An algebra exercise |
2007-01-24 |
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Clara pose la question : Given x + 2y = -2 and x - 2y = 18, find: a) x^2 - 4y^2 b) x^2 + 4y^2 Stephen La Rocque and Penny Nom lui répond. |
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What is the point of intersection of two sides of a polygon? |
2007-01-23 |
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Tyler pose la question : What is the point of intersection of two sides of a polygon? Stephen La Rocque lui répond. |
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Is -2^2 = -4 or 4? |
2007-01-23 |
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Joan pose la question : Is -2 squared, when written without parentheses around the -2, -4 or could this correctly be solved by squaring -2 (-2 x -2) for an answer of 4? Or, to correctly get an answer of 4, would the problem have to read (-2) squared? Stephen La Rocque lui répond. |
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Maximizing profit |
2007-01-23 |
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Denise pose la question : Total Profit= Total Revenue-Total Cost P(x)=R(x)-C(x) Where x is the number of units sold. Find the maximum profit and the number of units that must be sold in order to get that profit. R(x)=5x C(x)=.001x^2+1.2x+60 Stephen La Rocque lui répond. |
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Calculating a person's volume |
2007-01-20 |
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James pose la question : Hi i am currently trying to calculate my volume. I have tried to do this using a tank of water and measuring the difference. i worked out that my volume is 112 litres. my question is that i want to make a box that would hold my volume and so i need to convert it into centimeters. i know that there are 100 cm^2 in a litre. if i divide this by 4 i would be 91x91x91ft. is this simply to do with density. if so how could i make this more realistic? Stephen La Rocque lui répond. |
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A formula for figuring a tanks volume at various levels |
2007-01-20 |
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Dave pose la question : I know there has to be a general formula to figure out a tanks volume where as you know the total volume but you need to know what it will hold at various levels measured in 1/8th inches in depth and that you may be able to plug this formula into a program like say excel and thus create a chart unique to that tank. But for the lack of me I can not figure it out. Stephen La Rocque lui répond. |
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Irregular multi sided polygon |
2007-01-20 |
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Graham pose la question : I have an irregular polygon. I know the length of all the sides and know approximately all the internal angles. Is there a formula or table that can calculate the area for me? Steve La Rocque, Chris Fisher and Penny Nom lui répond. |
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The area of an irregular pentagon |
2007-01-18 |
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Ranjit pose la question : I would like to find the area of an irregular pentagon where the total perimeter is 1000m. Is there a Heron's formula for this? Stephen La Rocque lui répond. |
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Answer to skill testing question |
2007-01-18 |
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Mike pose la question : This question was on a ballot. Is the right answer 36 or 1? 5+2-1X6= Stephen La Rocque lui répond. |
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Points of intersection |
2007-01-18 |
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Mark pose la question : Find the points of intersection of the given pair of curves. 2x - 3y = -8 and 3x - 5y = -13 Steve La Rocque and Haley Ess lui répond. |
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The height of a triangle |
2007-01-17 |
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Sharon pose la question : I am needing to determine the height of a triangle with a 50 ft base and one side is 40 ft the other side being 30 ft. Penny Nom lui répond. |
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The volume of a frustum of a pyramid |
2007-01-17 |
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Sam pose la question : Find the volume of a frustum of a pyramid with square base of side b, square top of side a, and height h. Penny Nom lui répond. |
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The volume of a sphere |
2007-01-16 |
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Anshul pose la question : How to prove or find the volume of sphere? Harley Weston lui répond. |
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Where do the medians of a triangle meet? |
2007-01-02 |
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Brittany pose la question : Where do the medians of a triangle meet? 1. Inside the triangle v 2. On the traingle 3. Outside the traingle Stephen La Rocque lui répond. |
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Prove that square root of 3 is irrational. |
2006-12-21 |
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Humera pose la question : Prove that square root of 3 is irrational. Stephen La Rocque lui répond. |
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The product of of two rotations |
2006-12-17 |
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Katie pose la question : Is the product of of two rotations over a different center point always a translation? Walter Whiteley lui répond. |
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cos(n)pi = (-1)^n |
2006-12-14 |
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Idrees pose la question : How can I prove the following: cos(n)pi = (-1)^n Steve La Rocque lui répond. |
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The absolute value of imaginary and complex numbers |
2006-12-11 |
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Keith pose la question : i don't get how to find the absolute value of imaginary and complex numbers here is an examples from the text book the answers are given but they don't show the work so i can follow along just show me the work please and explain how it is done
problem 3+4i Stephen La Rocque and Penny Nom lui répond. |
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Factoring m^4-9^n |
2006-12-07 |
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Josh pose la question : I can not figure out how to completely factor m^4-9^n. Penny Nom lui répond. |
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The volume of an irregular tetrahedron |
2006-12-06 |
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Hai Van pose la question : Could you please show me the way to calculate the volume of an irregular tetrahedron Penny Nom lui répond. |
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Star of Bethlehem |
2006-12-05 |
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Stephen pose la question : I need to construct a star for a Christmas play being done at our church. I want it to be a four-pointed star. The top and side points should be 12 inches long and the bottom point 24 inches. It will be flat on the back but raised on the front with lights inside for illumination. Each point will be made of two triangles with a ridge in the center. I would like the width of the rays at the center (widest point or center of star) to be about five inches and the center ridge at this same point to be raised about two inches from the flat back. I need to know the dimensions and angles of each of the 8 triangles that make up the star so that all of them meet properly at the center of the star so as to have the correct height from the flat back. Penny Nom lui répond. |
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The height of a triangle |
2006-12-01 |
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Jeni pose la question : I need to know how to figure out the height of a triangle when all I know are the sides and base. The sides are 5 and the base is 8 What do I do? Penny Nom lui répond. |
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The game of 24 |
2006-11-28 |
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John pose la question : Math 24 with 9, 8, 4, 2? Stephen La Rocque and Penny Nom lui répond. |
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What proportion of cups of coffee have at least one defect |
2006-11-28 |
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Ayman pose la question : coffee machine may be defective since it dispenses the wrong amount of coffee (C) & or the wrong amount of suger ( S ) the probability of these defects are P(C) = 0.05, P(S) = 0.04 & P( C&S ) = 0.01 find 1- what proportion of cups of coffee have at least one defect 2- what proportion of cups of coffee have no defect Penny Nom lui répond. |
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Percentages |
2006-11-23 |
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Hyaqcinth pose la question : I just do not understand percentages...if the cost of a product is $1.20, how can I make a profit of 55% ? how do I calculate this problem? Stephen La Rocque lui répond. |
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Profit margin |
2006-11-22 |
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Kris pose la question : I just started a new sales position and need to calculate profit margins based on my cost of a given product. For example I have a piece of equipment that costs me $102,077.73. I need to figure a profit margin of 18% from cost to arrive at my sale price. What is the best way to do this? Penny Nom lui répond. |
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Factors |
2006-11-22 |
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Jacqueline pose la question : Why do the numbers 16,36,48,60,64,90 and 100 have an odd number of factors? Stephen La Rocque and Penny Nom lui répond. |
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Composition of functions |
2006-11-19 |
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RJ pose la question : Let f0(x) = 2/2-x and fn+1 = f0 o fn for n greater than or equal to 0. Find a formula for fn and prove it by mathematical induction. Recall that o represents function composition. i.e., (f o g)(x) = f(g(x)). Stephen La Rocque lui répond. |
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A particle moving along a curve |
2006-11-18 |
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Rachel pose la question : a particle is moving along the curve whose equation is: (xy^3)/(1+y^2)=8/5 assume the x-coordinate is increasing at the rate of 6 units per second when the particle is at the point (1,2). a. at what rate is the y-coordinate of the point changing at that instant? b. is the particle rising or falling at that instant? Penny Nom lui répond. |
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Composition of functions |
2006-11-18 |
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Oryan pose la question : Given f(x)=-2x^3 and g(x)-4x-5, find g(f(-1)) Stephen La Rocque lui répond. |
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An aircraft and a missile |
2006-11-18 |
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Sarah pose la question : an aircraft is flying at a constant altitude with a constant speed of 600mph. an antiaircraft missile is fired on a straight line perpendicular to the flight path of the aircraft so that it will hit the aircraft at a point P. at that instant the aircraft is 2 miles from the impact point P the missile is 4 miles from P and flying at 1200 mph. at that instant, how rapidly is the distance between missile and aircraft decreasing? Stephen La Rocque lui répond. |
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Wheat is poured on a conical pile |
2006-11-17 |
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Rachel pose la question : wheat is poured through a chute at the rate of 10 cubic feet per minute and falls in a conical pile whose bottom radius is always half the altitude. how fast will the circumference of the base be increasing when the pile is 8 feet high? Penny Nom lui répond. |
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A system of equations |
2006-11-13 |
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Katrina pose la question : solve the system of equations using either the substitution or the elimination method. 2x-3y= -12 and -4x+6y=15 Penny Nom lui répond. |
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The rate of change of the perimeter of a square |
2006-11-07 |
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Karli pose la question : Find the rate of change of the perimeter of a square with respect to its area. Stephen La Rocque lui répond. |
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A boat is being pulled towards a dock. |
2006-11-06 |
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Cassie pose la question : A boat is being pulled towards a dock. If the rope is being pulled in at 3 feet per second, how fast is the distance between the dock and the boat decreasing when it is 30 feet from the dock? Penny Nom lui répond. |
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Profit margin |
2006-11-04 |
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Beverly pose la question : Our costs to make a product is $73.00. We want to sell this product and make a 30 percent profit margin. What is the selling price? What is the simple formula to follow? Is there a chart we can go to that shows us these percentage of profit breakdowns Penny Nom lui répond. |
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Selling Price using Profit Margin |
2006-10-29 |
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Chris pose la question : What is the selling price of my inventory, find using the profit margin? Inventory A costs $2,300. The profit margin is 55% Inventory B cost is $4,500. The profit margin is 210%. Penny Nom lui répond. |
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An odd number of factors |
2006-10-28 |
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Anthony pose la question : What is the common name used for numbers that have an odd number of factors? This answer should be a two word answer only. Stephen La Rocque lui répond. |
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How much labor should the firm employ? |
2006-10-28 |
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Christy pose la question : A dressmaking firm has a production function of Q=L-L(squared)/800. Q is the number of dresses per week and L is the number of labor hours per week. Additional cost of hiring an extra hour of labor is $20. The fixed selling price is P=$40. How much labor should the firm employ? What is the resulting output and profit? I am having a difficult time with this, HELP! Stephen La Rocque lui répond. |
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(a^(1/3) – b^(1/3)) ( a^(2/3) + a^(1/3)b^(1/3) + b^(2/3)) |
2006-10-24 |
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Julie pose la question : (a1/3 – b1/3) ( a2/3 + a1/3b1/3 + b2/3) Haley Ess lui répond. |
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The area of a regular octagon |
2006-10-22 |
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Farhana pose la question : I have a regular octagon with sides of 0.8m and I need to find the area, Karen McIver and Penny Nom lui répond. |
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The height of a triangle as a function |
2006-10-19 |
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Ryan pose la question : Let 2s denote the length of the side of an equilateral triangle. Express the height of the triangle as a function of s Penny Nom lui répond. |
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How fast is the water level rising when the water is 1 meter deep? |
2006-10-19 |
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Don pose la question : The cross section of a 5-meter trough is an isosceles trapezoid with a 2-meter lower base, a 3-meter upper base and an altitude of 2 meters. Water is running into the trough at a rate of 1 cubic meter per minute. How fast is the water level rising when the water is 1 meter deep? Stephen La Rocque lui répond. |
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(2324/4)-525+214 |
2006-10-15 |
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Sherin pose la question : (2324/4)-525+214 Penny Nom lui répond. |
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A proof by induction |
2006-10-02 |
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Zamira pose la question : i'm studying induction but i don't get how to proof that 1+2+2^2+2^3+...+2^(n-1) = (2^n) - 1. Penny Nom lui répond. |
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Prove that 2nCn is less than 4n, for all positive integers n? |
2006-10-01 |
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Anna pose la question : How can I prove that 2nCn is less than 4n, for all positive integers n? Penny Nom lui répond. |
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Family of lines |
2006-09-29 |
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Sasha pose la question : could a "Family of Lines" have both parallel and intersecting equations that aren't related directly but otherwise related by each other to create a curve Chris Fisher lui répond. |
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BEDMAS |
2006-09-24 |
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Partick pose la question : if you have a question like this -(4)-(-4)+(-4)+4 how do you solve it step by step Penny Nom lui répond. |
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How many items must the company produce to begin to make a profit? |
2006-09-24 |
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Devon pose la question : The profit a manufacturing company makes can be found using the formula
P=120n - n^2 - 2200
How many items must the company produce to begin to make a profit? Stephen La Rocque lui répond. |
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Parameters |
2006-09-15 |
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Chase pose la question : What is the meaning of the word "parameters" when used in reference to Algebra. Penny Nom lui répond. |
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what is 8+(-2)(-5)/4-(-1)-4(-2+3) |
2006-09-08 |
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Jordan pose la question : what is 8+(-2)(-5)/4-(-1)-4(-2+3) Paul Betts lui répond. |
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The velocity of a pendulum, part II |
2006-09-07 |
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Erin pose la question : We saw the question in your database about the velocity of a pendulum swinging.....It is the same exact question....but there is another question......it says....
"estimate the instantaneous rate of change of d with respect to t when t = 1.5. At this time, is the pendulum moving toward or away from the wall? Explain." Harley Weston lui répond. |
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The lower half of a sphere |
2006-08-30 |
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Yvette pose la question : I am interested in finding out how to represent the lower half of a sphere in the form of z=f(x,y) with r=2 and a centre point (3,1). Stephen La Rocque and Penny Nom lui répond. |
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16X27+32÷4-26 |
2006-08-20 |
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Amanda pose la question : The question was 16X27+32÷4-26. Stephen La Rocque lui répond. |
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Points of intersection |
2006-08-20 |
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Gianella pose la question :
Find the points of intersection by solving this problem analytically.
y= x cubed
y= x
Stephen La Rocque lui répond. |
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Find the points of intersection |
2006-08-18 |
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Ingrid pose la question :
The question says find the points of intersection of the graphs of the equation, and check your results analytically.
x squared + y squared=25
2x+ y=10
Stephen La Rocque lui répond. |
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The development of trigonometry |
2006-08-15 |
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Eugene pose la question : Can you please give the exact time line of trigonometry. Penny Nom lui répond. |
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1/x + 1/y |
2006-08-11 |
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Sonya pose la question : what is 1/x+1/y = ? is it equal to 1/x+y or what? Penny Nom lui répond. |
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A problem with exponents |
2006-08-09 |
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A student pose la question : (8a to the negative 2 b cube c to the negative 4/4a squared b to the negative 3 c squared) to the negative 2 Stephen La Rocque lui répond. |
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Order of operations |
2006-06-29 |
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Jaden pose la question :
(1) A triangle has vertices at (-3,-3) (7,-3) and (-2,5). What is the area of the triangle?
Is there a way of doing this so that you dont have to graph it? If the x axis is horizontal can i say it is the base and the y-axis is horizontal meaning the height. Would I be able to do this...-3 to 7-->9 spaces, -3 to 5-->7 spaces-----9(7)63/2=31.5
(2) A cube has a surface area of 54 square centimeters. What is the volume of the cube in cubic centimeters?
Stephen La Rocque lui répond. |
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Order of Operations |
2006-06-29 |
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Marcy pose la question : I have been having problems with this skill testing question. I know the rules of operation but I don't understand why they would put it in brackets. Can you help me. I have two answers but I would like to know which one is right. Im having a disagreement with a friend over this matter. Thank you so much
[ (20 + 82 - 6) ÷ 16 ] x 14 Steve La Rocque and Paul Betts lui répond. |
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Marking out a circle |
2006-06-28 |
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Peter pose la question : given a straight line. how do i work out the off sets ( at right angles) at several intermediate points. to set out a 5.0m arc that has a 18.0m radius. Stephen La Rocque and Penny Nom lui répond. |
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A trig problem |
2006-06-24 |
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Greg pose la question : A and B are two towers, B being 4 km due east of A. The true bearings of a flagpole, C, from A and B are α east of north and α west of north respectively. The true bearings of a second flagpole, D, from A and B are (α + β) east of north and (α - β) west of north respectively. Assuming A, B, C, and D are on level ground, and that α = 25, β = 10, find the distance between C and D. Penny Nom lui répond. |
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The chord length of a polygon |
2006-06-14 |
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Krishna pose la question : I have to find out the chord length of a polygon - Tetradecagon ! The Radius of the Circle is 11.5 Cms. The Circle is intersepted by 14 arcs. Then how to find out the chord length? Stephen La Rocque lui répond. |
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A volume of revolution |
2006-06-07 |
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Colleen pose la question : Find the exact volume in cubic units generated by rotating a region, R, around the
y-axis, given that R is the region bounded by the curve y = x3 and the lines x = 1 and
y = 8. Penny Nom lui répond. |
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The coefficient of variation |
2006-05-20 |
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Glenn pose la question : What is the correct formula for coefficient of variation for a binomial distribution? Penny Nom lui répond. |
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More on the game of 24 |
2006-05-05 |
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Kathy's daughter pose la question : My daughter's 5th grade class plays the 24 math game. She came home
the other day with a real stumper! The numbers on the card are 5,5,2,and 6.
The rules say you must use every number,you may only use a number once,you
can only add, subtract, multiply and/or divide and the answer is 24. Can you
help!!!! No one where I work has been able to figure this one. Paul Betts and Penny Nom lui répond. |
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Proof by induction |
2006-04-24 |
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Meshaal pose la question : Find an expression for:
1-3+5 - 7 + 9 - 11 + ... + (-1)^(n-1) * (2n-1)
and prove that it is correct.
Stephen La Rocque lui répond. |
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Geometry proof |
2006-04-23 |
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Jade pose la question : From a point P outside a circle with centre O, tangents are drawn to meet the circle at A and B.
a) Prove that PO is the right bisector of the chord AB.
b) Prove that Stephen La Rocque lui répond. |
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What is the original cost? |
2006-04-19 |
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Charlie pose la question : Selling a piece of furniture for $670 and the profit is 35%. What is the original cost? Stephen La Rocque lui répond. |
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Proving a summation formula by induction |
2006-04-19 |
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Sharon pose la question : Prove by induction that the sum of all values 2^i from i=1 to n equals 2^(n+1) - 2 for n > 1. Stephen La Rocque lui répond. |
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How do you round off 89,100? |
2006-04-19 |
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Jeannie pose la question : My home work says to round each number to the place of the underlined digit. It has 89,100. The underlined number is 9. What do I do? Stephen La Rocque lui répond. |
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What is the cost price? |
2006-04-14 |
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Purushotham pose la question : If the selling price is 120 and the profit is 20%, what is the cost price? Stephen La Rocque lui répond. |
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A proof by induction |
2006-04-09 |
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Sharon pose la question : prove by induction: For every n>1, show that
2 + 7 + 12 + ...+ (5n-3) = n(5n-1)/2 Penny Nom lui répond. |
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Given three angles and a side |
2006-04-09 |
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Jon pose la question : How do you figure out the length of all sides of a scalene triangle if given the measure of all angles, and one side? Stephen La Rocque lui répond. |
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An octagon shaped soffit |
2006-04-08 |
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Ken pose la question : I am trying to make an octagon shaped soffit in my ceiling and need help figuring how to divide the circle on the ceiling into an octagon-
The circle is 7 foot in diameter. Penny Nom lui répond. |
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The average of monthly averages |
2006-04-06 |
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Ray pose la question : I have the averages of some data in percentages. the data is rather large, how can i find the average of these averages without going back to the original data? Is there a Factor or Constant that i could multiply or devide or add and get the average of these averages without resorting to the raw data. Steve La Rocque and Harley Weston lui répond. |
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A table of values |
2006-03-28 |
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Cindy pose la question : Create a table of values for each of the following functions: y=5x, y=52, and y=5x. I dont know to do this. Stephen La Rocque lui répond. |
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given that p is a prime and p|a^n, prove that p^n|a^n |
2006-03-24 |
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Janna pose la question : given that p is a prime and p|an, prove that pn|an Stephen La Rocque lui répond. |
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How far from Earth is Neptune? |
2006-03-21 |
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Scott pose la question : A laser beam travelling at the speed of light bounces off the planet Neptune and returns to Earth in 29 960.72 s. The speed of light is 299 792.5 km/s. How far from Earth is Neptune? Penny lui répond. |
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BEDMAS |
2006-03-21 |
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Andie pose la question : It's been a long time since I've used bedmas. I'm still confused as to what the answer to this question would be.
30 - (2 x 9) + (15/3)= Penny Nom lui répond. |
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Three towns are located at the vertices of an equilateral triangle |
2006-03-20 |
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A student pose la question : three towns are located at the vertices of an equilateral triangle. The towns are 8, 5, and 3 miles, respectively, from a store. How far apart are the towns? Chris Fisher lui répond. |
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The day of the week |
2006-03-19 |
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Neil pose la question :
A friend of mine has an excellent memory for dates and events that occurred on that date, but his party piece is the ability to tell you the day of the week that fell of any given date. This talent is all the more extraordinary because the answer comes back in less than 2 seconds (often under 1 second). By his own admission he is no mathematician.
Now his memory and knowledge are without question, but I challenged him that because of its diversity this party piece could not be based upon memory, but on mathematics. I believe that with the correct mathematical approach and the use of a common algorithm, anyone with a basic mathematical mind can do this in their head.
Chris Fisher lui répond. |
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Gross profit as a percentage |
2006-03-18 |
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Mark pose la question : How do I calculate the gross profit by percentage on and a product I purchased for $23.80 marked up 45% sold for $34.51 = profit of $10.71 GP by percentage???????? Penny Nom lui répond. |
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The square footage of an area in my backyard |
2006-03-17 |
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Kim pose la question : I need to find out how to calculate the square footage of an area in my backyard that is in the shape of a "slice of pie". There are two sides that are straight lines that come together at the top to form a point, and then at the bottom is a curved line that joins the two other lines together. I need to figure out how to calculate the square footage that is inside the area. Penny Nom lui répond. |
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9, 8, 7 and 2 in the game of 24 |
2006-03-17 |
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Alana pose la question : I just began student teaching in a 5th grade math class and found that the students play 24 in class, a game that I used to play in elementary school. The students choose a card which shows 4 numbers and then have to use any combination of addition, subtraction, multiplication, and division to reach 24. There was one card that we found that seems to have all of us stumped. The four numbers are 9, 8, 7 and 2. Can you figure out how to make 24 with those? Thanks so much for your help! Claude Tardif lui répond. |
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A proof by contraposition |
2006-03-16 |
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Eban pose la question :
1)by mathematical induction prove that 12 + 32 + 52 + ...... + (2k-1)2 = (1/3)k(2k-1)(2k+1) for all positive integers k.
2)show that the contrapositive of the following statement is true. if 1 + M7 is even, then M is odd.
Stephen La Rocque lui répond. |
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Profit |
2006-03-11 |
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Wendy pose la question : If I have a product I have bought for 33.58 and I mark it up by 30% sell at 43.65 how do I work out the gross profit. Penny Nom lui répond. |
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Factor |
2006-03-08 |
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Brad pose la question : Factor:
x3 + 64m3 and 125p3 - q6 Penny Nom lui répond. |
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The meaning of numbers |
2006-03-03 |
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John pose la question : I'm having a philosophical debate on the meaning of numbers, equations, or the world of math in general. Would it be possible if you could help me by giving me a resource that talks about it or if you have your own opinion I would be most grateful. Harley weston lui répond. |
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Profit |
2006-02-25 |
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Vernessa pose la question : ABC company wants to sell enough products to earn a profit of $40,000, if unit sales are $10 and variable costs $8 , fixed cost $80,000 how many units must be sold to earn a profit of $40,000. Penny Nom lui répond. |
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Victor's profit |
2006-02-13 |
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Millie pose la question : victor is trying to make money buying and selling cars. he saved up and buys a car for $2500 and then sells it for $4327.he then buys another car using 2/3 of his profit and sells it for twice what he paid for it. how much money did victor make during these transactions? Steve La Rocque lui répond. |
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Proof by induction |
2006-02-10 |
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Victoria pose la question :
how do i prove by induction on n that
n
Σ 1/i(i+1) = n/(n+1)
i=1
for all positive integers n
Penny Nom lui répond. |
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Prove that p^n >= (p!)/(p-n)! |
2006-02-02 |
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Rhydian pose la question :
PROVE:
pn >= (p!)/(p-n)!
Penny Nom lui répond. |
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More on the game of 24 |
2006-02-02 |
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Cathy pose la question : 10,16,9,4 this numbers have to equal up to 24. we can't figure it out. Claude Tardif lui répond. |
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BEDMAS |
2006-01-31 |
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Janielle pose la question : What Do All the Letters In BEDMAS Stand for? Penny lui répond. |
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How do you find the angles in a triangle? |
2006-01-27 |
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Keith pose la question : How do you find the angles in a triangle if you know the lengths of the sides? Chris Fisher and Penny Nom lui répond. |
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Our client wants to make 25% from their sale... |
2006-01-24 |
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Noelle pose la question : I need to figure out how to figure pricing for our clients. If our client wants to make 25% from their sale and they purchase it from me for $35.95, how do I figure what their cost is? Penny Nom lui répond. |
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One boundary of a pond is parabolic in shape. |
2006-01-20 |
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Glenn pose la question : One boundary of a pond is parabolic in shape. The boundary passes through the points A(-20,45), B(40,40) and E(30,35). The equation of the parabola is of the form y=ax2+bx+c. Find the equation of the parabola and the coordinates of the vertex of the parabola. Any assistance you could provide would be greatly appreciated. Penny Nom lui répond. |
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3x^4 - 81 |
2006-01-02 |
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Julio pose la question : How can I factor the following?:
3x4 - 81 Penny Nom lui répond. |
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Simultaneous Equations |
2005-12-21 |
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Matt pose la question : I have these two equations,
336 = 60a + 10b
and
432 = 84a + 6b
Am I right in saying both a and b are 4.8? Penny Nom lui répond. |
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The game of 24 with 7, 5, 5 and 4 |
2005-12-18 |
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Nicole pose la question : i was playing the 24 game the other day. you get 4 digits and you have to turn them into 24. You can use addition, subtraction, division, and multiplication. You have to use all the numbers but you can only use each number once. an example is 2 4 4 1 the answer is (2x4)(4-1)=24. I got stuck on one. The numbers were 7 5 5 4 . Penny Nom lui répond. |
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The sum of the angels in a triangle |
2005-11-25 |
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Rachel pose la question : how do you prove, without knowing any of the measurements or degrees, that the three angles of a triangle equal 180? what are the steps for proving that? Penny Nom lui répond. |
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BEDMAS |
2005-11-24 |
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Judy pose la question : My name is Judy and I am a grade 6 teacher.
We have just started our lessons on the order of operations and my students have asked me why we have BEDMAS and what is the logic to it.
Is there a reason that that we do math in this particular order?
Who invented this rule or how was it decided on and when? Walter Whiteley lui répond. |
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An isosceles triangle |
2005-11-14 |
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Chris pose la question : PX and QY are attitudes of acute triangle PQR, and Z is the midpoint of PQ. Can you write a proof that triangle XYZ is isosceles? Chri Fisher lui répond. |
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fog |
2005-11-12 |
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Janice pose la question : I am having problem with the (fog) function
(fog) (x). Given f(x)= 2x2 ; g(x)= 3-4x Penny Nom lui répond. |
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Coefficient of variation |
2005-10-19 |
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Jan pose la question : I am currently teaching the coefficient of variation and am wondering if there are some guidelines as to the interpretation of this statistic. I understand that it measures the variation in a variable relative to the mean - but what is the cut off for "too much" variation expressed in this way???
Andrei Volodin and Penny Nom lui répond. |
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The coefficient of thermal expansion for steel |
2005-10-14 |
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Jim pose la question :
Is the following statement true?
“The coefficient of thermal expansion for steel is 0.00000645in/in/deg. Doesn't sound like much but when you run out the numbers it comes to .405504 ft/mile/deg. Still doesn't sound like much, only about 5". Then multiply by 40 degrees and you get a piece of rail that has grown by 16.22 feet in that one mile. It's not at all unusual for the rail temp to go from say, 40 deg to 80 deg on a spring or fall day. Remember that on a sunny day, the rail temp can be significantly higher than the air temp as well."
I ran the math and came up with an answer closer to 16 inches, instead of 16 feet. Which is closer to being correct?
Penny Nom lui répond. |
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The game of 24 |
2005-10-10 |
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Kim and Chris pose la question : My 4th grade son came home with a math game 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: 9, 9, 9, 9. And they must equal 24. Any clues? Claude Tardif lui répond. |
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Prove that a rhombus' diagonals are perpendicular |
2005-10-02 |
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Tania pose la question : How do you prove that a rhombus' diagonals are perpendicular using the 2 column proof method? Walter Whiteley lui répond. |
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A system of equations |
2005-09-02 |
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Gina pose la question : How do you interpret the solution of a system of equations by the corresponding graph? Demonstrate your answer by the use of an example. Penny Nom lui répond. |
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BEDMAS |
2005-09-01 |
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A student pose la question : I am a student and am wondering about the answer to this question.
56/2(31)
is the answer 7?
Harley Weston lui répond. |
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Proof by induction? |
2005-08-10 |
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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. |
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Profit of more than 100% of cost |
2005-06-22 |
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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. |
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20% profit |
2005-06-12 |
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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. |
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The sum of the digits of 2^100 |
2005-06-11 |
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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. |
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y = x+2 and y = 2x - 1 |
2005-05-03 |
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Kimberley pose la question : Question:
y=x+2
y=2x-1 Penny Nom lui répond. |
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40% profit |
2005-04-19 |
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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. |
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A flaw in a problem |
2005-04-15 |
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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. |
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Dimensions of a roof |
2005-03-18 |
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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. |
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The game of 24 |
2005-01-10 |
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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. |
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Profit |
2005-01-10 |
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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. |
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An isosceles triangle |
2005-01-03 |
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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. |
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2^9833 days from today |
2004-12-26 |
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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. |
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A geometric proof |
2004-12-11 |
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Hanna pose la question : Given: ABCD is a quadrilateral;
Prove: ABCD is a parallelogram Penny Nom lui répond. |
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"a" cubed minus "b" cubed |
2004-12-02 |
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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. |
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The substitution method |
2004-11-28 |
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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. |
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Proof by induction |
2004-11-20 |
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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. |
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Order of operations |
2004-11-10 |
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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. |
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Bedmas |
2004-11-09 |
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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. |
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Solving triangles |
2004-10-30 |
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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. |
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Bedmas |
2004-10-30 |
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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. |
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Maximize income |
2004-10-24 |
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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. |
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Solve for a and t |
2004-10-23 |
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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. |
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A rate of change problem |
2004-10-15 |
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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. |
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Accelerating to the speed of light |
2004-09-30 |
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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. |
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A theorem involving a trapezoid |
2004-09-29 |
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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. |
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The volume of a pile of mulch |
2004-09-22 |
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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. |
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The method of substitution |
2004-09-20 |
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Kayla pose la question : y=x-1
y=2x-3 Harley Weston lui répond. |
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The game of 24 |
2004-09-16 |
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Angelica pose la question : how can you make 24 out of 7,7,6,5? Claude Tardif lui répond. |
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The game of 24 |
2004-09-14 |
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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. |
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The 24 game |
2004-09-09 |
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Erik pose la question : Ive spent around 40 hours on this one problem. I need help. 3,3,7,7 Claide Tardif lui répond. |
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Order of operations |
2004-09-04 |
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Leanne pose la question : 6 + 3 - 2 x 3 = Claude Tardif lui répond. |
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50/5x - y |
2004-08-22 |
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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. |
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an integer with three factors |
2004-08-03 |
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A student pose la question : What is the probability that a randomly chosen 3 digit number has exactly 3 factors Penny Nom lui répond. |
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The law of sines |
2004-08-01 |
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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. |
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Rate of change problems |
2004-08-01 |
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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. |
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Factoring |
2004-07-19 |
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A student pose la question : Factor completely:
3x3 - 24y3
54x6 + 16y3
16xy - 4x - 4y - 1
0.09x2 - 0.16y2 Penny Nom lui répond. |
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A proof in geometry |
2004-07-16 |
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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. |
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The Number of the Beast |
2004-06-13 |
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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. |
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The game of 24 |
2004-06-04 |
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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. |
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Finding bearings |
2004-05-24 |
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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. |
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Angles of elevation and depression |
2004-05-18 |
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Anjum pose la question : what is the difference between an angle of elevation and angle of depression? Penny Nom lui répond. |
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Three dice |
2004-05-10 |
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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. |
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3x squared - 27 / x + 3 |
2004-05-04 |
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Stef pose la question : 3x squared - 27 / x + 3 Penny Nom lui répond. |
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Factoring |
2004-04-27 |
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Bipin pose la question : FACTORISE:
a to the power of 6 + b to the power of 6 Penny Nom lui répond. |
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The problem of Apollonius |
2004-04-25 |
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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. |
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Some factoring problems |
2004-04-15 |
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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. |
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x^2/3 - 7 x^1/3 + 12 = 0 |
2004-04-05 |
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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. |
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(3x50)+20/5=? |
2004-04-03 |
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A student pose la question : what is the answer to:
(3x50)+20/5=? Penny Nom lui répond. |
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n! > n^2 |
2004-03-30 |
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Jose pose la question : How can you prove by mathematical induction that:
n! > n2. Penny Nom lui répond. |
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BEDMAS |
2004-03-20 |
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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. |
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Sum of the angles in a pentagon |
2004-03-11 |
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Ashish pose la question : What is the sum of all the measures of the angles of a Pentagon Penny Nom lui répond. |
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Proof by induction |
2004-03-02 |
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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. |
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Profit, markup and discount |
2004-02-22 |
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Kick pose la question : Using the calculation on your website, if I sell something for $885 and my cost is $296, I make $589 profit. How do I calculate the profit percent I made on that transaction?
Profit as a percentage of what it cost me?
Profit as a percentage of what I sold it for?
Penny Nom lui répond. |
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The substitution method |
2004-02-14 |
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Keisha pose la question : I need to solve this problem by using the substitution method.
3x+y=1
x=2y+5
Please help me understand the method to solve. Penny Nom lui répond. |
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Profit |
2004-02-12 |
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Mohamed pose la question : if i bought some thing with 100$ and the saller told me that his profit was 30% how can i know the actual price of the good Penny Nom lui répond. |
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Order of operations |
2004-01-28 |
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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. |
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BEDMAS |
2004-01-21 |
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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. |
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The sides of a circle |
2004-01-07 |
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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. |
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How far can you see? |
2003-12-15 |
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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. |
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Room and board fees |
2003-11-29 |
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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. |
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Mr.Carter is very cautious |
2003-11-26 |
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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. |
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Markup, profit and margin |
2003-11-24 |
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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. |
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Difference of squares |
2003-11-24 |
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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. |
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Laws of sines and cosines |
2003-11-23 |
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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. |
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Systems of equations |
2003-11-19 |
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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. |
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Adding fractions |
2003-11-16 |
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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. |
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Divisibility by 7 |
2003-11-14 |
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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. |
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What is a number that has exactly 13 factors? |
2003-11-09 |
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Mary pose la question : What is a number that has exactly 13 factors? Penny Nom lui répond. |
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Which one has the most factors? |
2003-10-31 |
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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. |
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Standard Deviation |
2003-10-07 |
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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. |
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The Sieve of Eratosthenes |
2003-09-18 |
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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. |
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Substitution method |
2003-09-14 |
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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. |
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Order of operations |
2003-09-07 |
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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. |
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The game of 24 |
2003-09-03 |
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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. |
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Profit margin |
2003-09-03 |
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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. |
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A pyramid with its top cut off |
2003-07-21 |
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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. |
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4-3(m+1)=(-38) |
2003-06-25 |
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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. |
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Two trig problems |
2003-06-10 |
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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. |
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BEDMAS |
2003-05-31 |
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Kristie pose la question : (3x50)+20/5=?
I know bedmas but i forget how to do it. Penny Nom lui répond. |
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x-6square root of x +8=0 |
2003-05-10 |
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Elizabeth pose la question : x-6square root of x +8=0 Penny Nom lui répond. |
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2/sqrt(2) |
2003-05-07 |
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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. |
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Rules of exponents |
2003-05-05 |
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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. |
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The volume of air flowing in windpipes |
2003-05-02 |
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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. |
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positive multiples of 10 that are the sum of four consecutive integers |
2003-05-01 |
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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. |
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Profit for a dance studio |
2003-04-28 |
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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. |
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Can twice a square be a square? |
2003-03-25 |
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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. |
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Three proffs of a trig identity |
2003-03-18 |
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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. |
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Three digit number |
2003-03-10 |
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Grace pose la question : What three digit positive integer is exactly 32 times the sum of its digits? Claude Tardif lui répond. |
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Order of operations |
2003-02-16 |
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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. |
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Order of operations |
2003-02-15 |
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Debbie pose la question : Question: 20-(9+4)x7=? Possible answer -71 or 49? Penny Nom lui répond. |
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BEDMAS |
2003-02-09 |
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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. |
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Dorothy and the wizard |
2003-01-24 |
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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. |
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The intersection of conics |
2002-12-19 |
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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. |
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Factoring |
2002-12-11 |
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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. |
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A two stage rocket |
2002-11-26 |
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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. |
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Factor completely |
2002-11-21 |
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Shelley pose la question : these two questions are to be factored completely but i have no idea how to factor them - (x-4y) 2 - 3(x-4y) - 4
- x 6 + y 6
Penny Nom lui répond. |
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The 24 game |
2002-11-16 |
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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. |
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The percentage grade of that hill |
2002-11-05 |
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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. |
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The repetition of doing many straight forward problems |
2002-10-16 |
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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. |
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Proof by induction |
2002-09-26 |
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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. |
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Fractional exponents |
2002-09-20 |
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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. |
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The number of decimal places in 1 over a power of 2 |
2002-09-12 |
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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. |
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Proof by induction |
2002-08-31 |
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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. |
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38-10+12divided by4multiplied by 16 |
2002-08-30 |
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Brenda pose la question : my math question is as follows: 38-10+12divided by4multiplied by 16=? Penny Nom lui répond. |
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Common Denominator |
2002-08-26 |
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Slobodanka pose la question : What is a Common Denominator? Penny Nom lui répond. |
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Sole Mates Shoes |
2002-08-19 |
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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. |
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Volume of a sphere |
2002-08-16 |
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Rahul pose la question : How do i find the volume of a sphere without the knowledge of calculus? Walter Whiteley lui répond. |
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Two equations |
2002-07-26 |
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Derek pose la question : 1. 3x + 2y = 4 2. -7x + 2y = 24 finding x and y. Penny Nom lui répond. |
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Some inequalities |
2002-07-25 |
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A student pose la question :
1)-5 <= -3X+1 < 1 2)4X-2 < 6 OR X+2 > 9 Penny Nom lui répond. |
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Domain of a function |
2002-07-20 |
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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. |
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Order of operations |
2002-07-18 |
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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. |
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Constructing the square root of 3 |
2002-06-07 |
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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. |
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A spotlight shines on a wall |
2002-05-25 |
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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. |
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How far apart are the transmitters? |
2002-05-18 |
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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. |
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The law of cosines and obtuse angles |
2002-05-09 |
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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. |
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8/13*26/27 |
2002-05-01 |
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Arias pose la question : 8/13*26/27= Penny Nom lui répond. |
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An augmented matrix |
2002-04-20 |
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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. |
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The square root of four |
2002-04-13 |
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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. |
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Calculate profit |
2002-04-13 |
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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. |
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Composition of functions |
2002-04-06 |
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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. |
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Pairs of equations |
2002-04-04 |
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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. |
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Some 5 card hands |
2002-03-28 |
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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. |
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A hamburger and a soft drink |
2002-03-23 |
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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. |
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24x^4 + 3x |
2002-03-18 |
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gary pose la question : 24x 4 + 3x Penny Nom lui répond. |
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Testing a hypothesis |
2002-03-14 |
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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. |
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The square root of i |
2002-03-14 |
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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. |
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The isosceles triangle of smallest area |
2002-03-08 |
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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. |
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The square root of 2 |
2002-03-05 |
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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. |
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Proof by induction |
2002-02-20 |
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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. |
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Rolling 5 sevens before rolling a six or an eight |
2002-01-20 |
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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. |
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Making 24 |
2002-01-17 |
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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. |
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What is a group of three numbers called in a large number? |
2002-01-15 |
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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. |
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Adding vectors |
2002-01-12 |
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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. |
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All of the Christmas trees are fifty-five percent off. |
2002-01-08 |
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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. |
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Catenary |
2002-01-02 |
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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. |
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Composition of functions |
2001-12-16 |
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Paula pose la question :
- if f(x)= 3x-1 and g(x)= 1/2x + 3 find fog(2)
- find the values of x for which tanx=0
Penny Nom lui répond. |
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Piles of coins |
2001-12-05 |
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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. |
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2=the square root of (2 + the square root of (2 + the square root of (2 +...))) |
2001-11-05 |
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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. |
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Squares of negative numbers |
2001-11-03 |
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Susana pose la question : I wanted to know if I can square a negative number..? Leeanne Boehm lui répond. |
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Proof by induction |
2001-10-16 |
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John pose la question : Can you help me with any of these? - For any natural number n > 1, prove that
(4n) / (n + 1) < [(2n)!] / [(n!)2].
- For any natural number n > 1, prove that
1/sqrt(1) + 1/sqrt(2) + 1/sqrt(3) + ... + 1/sqrt(n) > sqrt(n).
- For any natural number n and any x > 0, prove that
xn + xn - 2 + xn - 4 + ... + x-n >= n + 1. Penny Nom lui répond. |
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Some algebra |
2001-10-15 |
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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. - (7x2 – 3yz)2 – (7x2 + 3yz)2
- Use Pascal’s triangle to expand (2x – y)4
- 8x3 y - x3 y4
- (m + 3n)2 – 144
- 12x4 y – 16x3 y2 – 60x2 y3
- p3 q2 – 9p3 + 27q2 – 243
Peny Nom lui répond. |
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Rules of exponents |
2001-10-14 |
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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. |
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Proof by induction |
2001-09-30 |
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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. |
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Ciefficient of variation |
2001-09-23 |
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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. |
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A 91-gon |
2001-09-10 |
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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. |
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The best of 7 |
2001-09-08 |
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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. |
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Sharing a donut |
2001-09-06 |
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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. |
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Fourier transform |
2001-08-07 |
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Adbul pose la question :
- 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?
- 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. |
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How far does the fly fly? |
2001-08-07 |
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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. |
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Linear regression |
2001-08-01 |
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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. |
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e^pi > pi^e |
2001-07-27 |
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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. |
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Margin of error |
2001-07-13 |
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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. |
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The speed of the boat |
2001-07-12 |
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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. |
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Harmonic numbers |
2001-05-23 |
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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. |
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A pile of sand |
2001-05-14 |
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Gul pose la question :
- 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. |
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The angles in a triangle |
2001-05-11 |
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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. |
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Maximize profit |
2001-05-09 |
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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. |
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A sequence of even terms |
2001-04-29 |
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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. |
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A geometry proof |
2001-04-18 |
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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. |
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A famous landmark |
2001-03-23 |
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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. |
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Systems of equations |
2001-03-16 |
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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. |
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How can you prove a quadrilateral to be a parallelogram? |
2001-03-16 |
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Joy pose la question : How can you prove a quadrilateral to be a parallelogram? Walter Whiteley lui répond. |
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Names of the polygons |
2001-03-15 |
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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. |
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The angle of elevation |
2001-03-08 |
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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. |
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problem of the week |
2001-03-06 |
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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. |
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Powers |
2001-03-04 |
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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. |
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Difference of Squares |
2001-02-22 |
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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. |
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Mr. Moser's roof |
2001-02-21 |
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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. |
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Math game 24 |
2001-02-21 |
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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. |
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The law of cosines in the real world |
2001-02-21 |
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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. |
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Undecagon |
2001-02-21 |
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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. |
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A pole next to a building |
2001-02-20 |
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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. |
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Law of cosines |
2001-02-20 |
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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. |
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Difference of squares |
2001-02-20 |
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Janna pose la question : Hi! I was just wondering how you would factor x2 - 9y2. Harley Weston lui répond. |
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Delivering firwood |
2001-02-20 |
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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. |
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Buckets of golf balls |
2001-02-08 |
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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. |
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1 + 1 = 1 |
2001-01-23 |
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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. |
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64.5% profit |
2001-01-12 |
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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. |
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The laws of sines and cosines |
2001-01-02 |
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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. |
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Factoring (u-v)3+v-u |
2000-12-15 |
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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. |
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An integration problem |
2000-11-30 |
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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. |
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Vector Problem |
2000-11-27 |
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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. |
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Order of operations |
2000-11-26 |
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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. |
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Pillows and Cushions |
2000-09-27 |
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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. |
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A proof that 1=2 |
2000-09-19 |
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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. |
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Order of operations |
2000-09-19 |
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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. |
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Two linear equations |
2000-09-14 |
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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. |
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Induction |
2000-09-07 |
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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. |
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Velocity of a pendulum |
2000-08-28 |
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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. |
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The sum of the squares of 13 consecutive positive integers |
2000-08-25 |
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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. |
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The angle of rotation |
2000-08-03 |
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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. |
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Two linear systems |
2000-08-01 |
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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. |
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An equation involving x to the x |
2000-07-22 |
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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. |
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Parallel tangents |
2000-06-30 |
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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. |
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Central Limit Theorem and Law of Large Numbers |
2000-06-26 |
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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. |
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The speed of light |
2000-06-19 |
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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. |
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Powers of i |
2000-05-24 |
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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. |
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The equation of a parabola |
2000-05-22 |
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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. |
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Calculus Research Questions |
2000-05-22 |
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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. . . . Harley Weston lui répond. |
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The square root of -1 |
2000-05-19 |
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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. |
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A matrix equation |
2000-05-14 |
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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. |
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The Village of Truth |
2000-05-10 |
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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. |
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All the roots of x^6 - 64 |
2000-04-15 |
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Dakota pose la question : Find ALL zeros of P(x) = x 6 - 64 Walter Whiteley lui répond. |
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The square root of 3 |
2000-04-04 |
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Mr. William pose la question : Prove that root 3 is irrational Harley Weston lui répond. |
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Taxis in Chicago |
2000-03-27 |
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A high school studenthigh 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. |
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Rule of 78 |
2000-03-22 |
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Dan Baumgarten pose la question : Can you explain the rule of 78 and the reverse rule of 78? Thanks. Claude Tardif lui répond. |
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Surface area of a sphere |
2000-03-22 |
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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. |
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A system of equations in five unknowns |
2000-03-20 |
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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. |
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Induction |
2000-03-16 |
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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. |
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Eligibility in a contest |
2000-03-14 |
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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. |
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Simultaneous equations |
2000-03-11 |
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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. |
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Congruent parts of congruent figures |
2000-03-10 |
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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. |
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Systems of linear equations |
2000-03-10 |
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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. |
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Angle of Intersection of Two Lines |
2000-03-02 |
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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. |
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Order of operations |
2000-02-27 |
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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. |
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Party favors |
2000-02-22 |
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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. |
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The quotient rule |
2000-02-21 |
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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. |
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2 = 1 |
2000-02-16 |
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Chuck Kennedy pose la question : Question: - Assume a=b
- Multiply both sides by a, a2=ab
- Subtract b2, a2-b2=ab-b2
- Factor (a-b)(a+b)=b(a-b)
- Cancel like factors a+b=b
- Substitue b for a b+b=b
- Then 2b=b
- Therefore 2=1
Question; Were is the mistake? Claude Tardif lui répond. |
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Play ball |
2000-02-03 |
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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. |
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Names of the polygons |
2000-01-29 |
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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. |
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Order of operations |
2000-01-16 |
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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. |
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A roll of paper |
2000-01-15 |
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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. |
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Factoring ^6 |
2000-01-03 |
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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. |
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zero |
2000-01-01 |
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Jason pose la question : What civilization first used zero? Penny Nom lui répond. |
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Two algebra problems |
1999-12-17 |
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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. |
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Sines & cosine laws |
1999-12-10 |
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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. |
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Systems of equations |
1999-12-06 |
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Roger Hornbaker pose la question : I am having problem figuring out x and y solutions. - 5x + y = 4
3x - y = 4 - 3x + 2y = 6
- 3x + y = 0 Penny Nom lui répond. |
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order 4+ determinants |
1999-12-06 |
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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. |
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How many 3/5 are in 3/4? |
1999-12-06 |
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Whiteny pose la question : How many 3/5 are in 3/4? Penny Nom lui répond. |
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Zero to the zero |
1999-12-02 |
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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. |
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Estimating the population mean |
1999-11-13 |
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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. |
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Inverses of functions |
1999-11-01 |
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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. |
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Powers of zero |
1999-10-31 |
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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. |
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Order of operations |
1999-10-25 |
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Garrett pose la question : 99*(57+76)*9-1085/9 Penny Nom lui répond. |
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An odd number of factors |
1999-10-22 |
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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. |
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(-5)^2, -5^2 and -(5)^2 |
1999-10-13 |
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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. |
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Length of a line |
1999-10-10 |
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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. |
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Trigonometry history |
1999-09-25 |
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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. |
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-8*-(-5a)=15 |
1999-09-22 |
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Shelby pose la question : -8*-(-5a)=15 i cannot get this question!! please help me!! Harley Weston lui répond. |
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Surface area of a cone |
1999-09-18 |
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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. |
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Bales of hay |
1999-09-13 |
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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. |
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2,5,8,1 yields 24 |
1999-09-12 |
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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. |
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Towers of Hanoi |
1999-09-03 |
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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. |
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The sum of the cubes is the square of the sum |
1999-08-25 |
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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. |
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Why is slope designated m? |
1999-08-18 |
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Peter Komlos pose la question : Why is the slope of a line is designated by the letter "m"? Penny Nom lui répond. |
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From an airport control tower |
1999-08-04 |
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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. |
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A difference of squares problem. |
1999-07-24 |
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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. |
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An Invalid Argument |
1999-05-31 |
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Rod Redding pose la question : Can an invalid argument have a true conclusion? If yes then why? Walter Whiteley lui répond. |
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Introductory Algebra |
1999-05-19 |
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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. |
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A |
1999-05-02 |
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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. |
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Parallel and perpendicular lines |
1999-04-23 |
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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. |
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Radius of an arc |
1999-04-22 |
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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. |
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Radius of convergence |
1999-04-21 |
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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. |
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The average rate of change of a function |
1999-04-20 |
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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. |
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Volume of oil in a tank |
1999-04-17 |
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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. |
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y=mx+b |
1999-04-15 |
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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. |
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Factoring |
1999-03-30 |
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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. |
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0/11 |
1999-03-09 |
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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. |
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Factoring |
1999-03-08 |
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L. Sivad pose la question : Question: m2+6m+9-n2 Penny Nom lui répond. |
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Reversing the direction of an inequality. |
1999-03-06 |
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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. |
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The square root of two is never supposed to end |
1999-03-06 |
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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. |
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Root 17 is Irrational |
1999-01-21 |
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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. |
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Pythagorean theorem research project |
1998-12-31 |
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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. |
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Duplation method of multiplication |
1998-11-26 |
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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. |
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Linear systems of equations |
1998-11-16 |
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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. |
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A Sum or Product of Fractions |
1998-10-06 |
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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. |
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Radicals |
1998-09-15 |
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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. |
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Volumes |
1998-08-29 |
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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. |
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Volumes of Revolution |
1998-07-24 |
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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. |
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Difference of squares |
1998-06-23 |
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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. |
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Graph question |
1998-05-12 |
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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. |
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The day of the week, July 24, 1837 |
1998-03-21 |
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Colleen K. pose la question : What day of the week (Mon. Tues. Wed. etc...) was July 24th, 1837? Chris Fisher lui répond. |
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(50^20)(20^50) |
1998-02-24 |
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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. |
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Intersecting Lines. |
1998-02-10 |
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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. |
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Cos(x) Cos(2x) Cos(4x)=1/8 |
1997-09-24 |
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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. |
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The Range of a Function. |
1997-09-12 |
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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. |
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Proofs |
1997-04-13 |
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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. |
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A Presidential Proof |
1997-03-18 |
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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. |
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Ajax, Beverley, Canton and Dilltown |
1997-03-14 |
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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. |
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