







2^x= 2x  11 
20161127 

Kathy pose la question : I don't know how to start this problem:
2^x= 2x  11 Penny Nom lui répond. 





The height of a parabolic arc 
20151230 

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. 





Using Newton's Method to find a root 
20120409 

Nancy pose la question : Use Newton's method to find the real root function, accurate to five decimal places
f(x) = x^5+2x^2+3 Penny Nom lui répond. 





A quadratic equation 
20100315 

rachelle pose la question : under certain condition, it is found that the cost of operating an automobile as a
function of speed is approximated by a quadratic equation. use the data shown
below to find the function. then use the function to determine the cost of operating
the automobile at 60mph.
speed
(in miles per hour) 
operating cost
per mile(in cents) 
10 
22 
20 
20 
50 
20 
Penny Nom lui répond. 





A Lagoon, free form, inground swimming pool 
20091222 

donna pose la question : What is the linear footage of a 14 x 23, Lagoon, free form, inground swimming pool? Robert Dawson lui répond. 





Figure out the square root of something 
20091220 

eric pose la question : is there an ez equation to figure out the square root of something? Harley Weston lui répond. 





The acute angle formed by intersecting lines 
20091217 

Katie pose la question : To the nearest tenth of a degree, find the size of the acute angle formed by the intersecting lines 3x + 2y = 12 and x  2y = 2. Was is necessary to find the intersection point? Robert Dawson lui répond. 





The volume of a pond 
20081104 

Malcolm pose la question : I am looking for a formula to find the volume of my pond. I know the average surface diameter and the average bottom arc length.(The arc from one bank through a point in the bottom and on to the surface on the other bank. I am not able to get a good measurement of the depth at this time. Can the volume be figured with the known measurements (the cord and the arc)? Thanks: MS Harley Weston lui répond. 





The cube root of a really big number 
20080717 

Pete pose la question : Is the only way to find a cube root of a really big number guess and check, as i read in other questions, or is there another way without a calculator? Harley Weston lui répond. 





The square root of 21 between what two numbers? 
20080403 

Danielle pose la question : The square root of 21 between what two numbers? Penny Nom lui répond. 





The cube root of 198 
20080327 

bobby pose la question : what is the cubed root of 198 Harley Weston lui répond. 





Solve sin(x)=x^2x 
20071211 

ming pose la question : is there anyway you can solve
sin(x)=x^2x without a calculator? Stephen La Rocque lui répond. 





The normal approximation to the binomial 
20070930 

m.j. pose la question : Slot Machines The probability of winning on a slot machine is 5%. If a person plays the machine 500 times, find the probability of winning 30 times. Use the normal approximation to the binomial distribution. Harley Weston lui répond. 





The irrationality of PI 
20070807 

Matthew pose la question : I have what I like to think of as a rather interesting question that I can't explain confidently for the life of me.
If we take a circle with a radius of 1 and we calculate the circumference, we can use 2 pi R.
Doing this calculation results in a circumference of 6.28318530717~ which goes on forever.
However, if you were to take a that same circle in the real world, say with radius 1cm and wrap a string around
it, and then measure the string, you don't get 6.28~, you get something like 6.2, a much more finite distance. The length
of the string is not an irrational number, like the math claims it to be. Claude Tardiff and Stephen La Rocque lui répond. 





Finding square roots 
20070517 

Chandler pose la question : I would like an easy way to find the square root of a number. Gabriel Potter lui répond. 





x^x = 2x 
20070222 

ramsay pose la question : This has been bugging me for ages. How do find both real solutions to x^x = 2x? Obviously I have x=2, and there's another at about 0.35, but I can't work it out properly. Any help? Penny Nom lui répond. 





Large exponents 
20070209 

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. 





The cube root of 8000 
20070131 

Jacqui pose la question : How would you find the answer of a cube root backwards. For example: 8000 but backwards. Like, what number made that and how would you do it? Penny Nom lui répond. 





How does knowing the sum for 2+7 help you find the sum for 6+1 
20061026 

Andrea pose la question : How does knowing the sum for 2+7 help you find the sum for 6+1 Haley Ess lui répond. 





An approximation 
20061022 

Ellen pose la question : consider the curve 8x^2 +5xy+y^3 +149 =0 Write an equation for the line tangent to the curve at (4, 1) use this equation to approximate the value of K at the point (4.2, K) Penny Nom lui répond. 





The area of a sector and a triangle 
20060623 

Howard pose la question : I thought of the following problem which is similar but much simpler than the tethered goat problem: What is the angle(it is more illustrative in degrees)of arc of a unit circle so that the area between the chord it subtends and the arc length is equal to the area of the triangle with opposite side the subtended chord. Stephen La Rocque and Penny Nom lui répond. 





The interior angles of a right triangle 
20060520 

Greg pose la question : I am wondering if there is a way to figure out the interior angles of a right triangle if we know ONLY the side lengths, and the trick is, we CANNOT use arctangent! Leeanne Boehm and Penny Nom lui répond. 





Approximating an integral 
20050127 

A student pose la question : i used excel to find the area under a graph instead of integrating the function the analytical way. These are the different answers i got with different width of the xvalues, the smaller the xincrement gets the more precise the area is when compared to the answer obtained the numerical way. I have trouble seeing why the answers i get is getting bigger and bigger and not smaller can someone plz explain? Penny Nom lui répond. 





12(1.221)^t = t + 3 
20040714 

Jay pose la question : This problem has me stumped since i cannot separate the t and the 3. Here it is:
12(1.221)^{t} = t + 3
It's on a logarithm worksheet, but how do i figure it out?! Harley Weston lui répond. 





Programming without trig functions 
20040525 

Derek pose la question : I am a programmer trying to calculate the following.
What is the formula to find the crosssectional area of a cylinder with out using any trig functions? or better yet, how can you calculate any given volume in a cylindrical tank with spherical heads with out trig functions?
I am using a PLC (programmable logic controller) to do this and trig functions are not available. Harley Weston lui répond. 





Rounding 27.27 
20021103 

A parent pose la question : If you have a problem 27.27 and you need to round to the first 7 the answer would be 27 Would 27.0 be acceptable as well or is it completely wrong. Penny Nom lui répond. 





x^{ 4} + x^{ 5} = 100 
20021027 

Bill pose la question : One of my students has stumped me. He asked how to solve the equation 4^{ x} + 5^{ x} = 100 All I can think of are graphing methods to get an approximate solution. What am I missing? Harley Weston lui répond. 





Cube roots 
20020326 

Kathy pose la question : My son is in 4th grade and needs to simplify the cube roots of 216, 512 and 64. How does he do this with a regular calculator or without? Penny Nom lui répond. 





Approximating 260 divided by 3 
20010402 

Andrew pose la question : Choose the letter of the best estimate. 260 divided by 3 a. 60 b. 70 c. 90 d. 100 Paul Betts lui répond. 





Cube roots on a calculator 
20010324 

Will pose la question : Hi my name is Will.I have a question about the calculator TI83 Plus or the use of a scientific calculator. It is about using them to turn a cubed root to a decimal. When using that for a rational and irrational number. Rational numbers is a number that terminates or repeates. A irrational number goes on and on and uses ... (like pie). Like when you type the cube root of 8 it gives you 2, and that is a rational number. The squre root of 2 is 1.41421356... that is irrational. So why is it when you put the cube root of 16 in the calculator it says 2.5198421 that is rational it terminates at the ninth digit and my float is set for the tenth? But why when you do it by hand you get the 2 times the cube root of 2 and that is irrational? Why is that? Judi McDonald lui répond. 





Finding roots 
20010201 

A student pose la question : My math problem is right now we are working on roots. I don't quite understand how to find the answer to the problems, i was wondering what is the easiest, and fastest way to find the answers to roots? Penny Nom and Claude Tardif lui répond. 





Solving x  sin(x) = constant 
20001229 

Keith Roble pose la question : If x is in radians, how do you solve for x, where: xsin(x) = constant? Harley Weston lui répond. 





Rounding 
20000415 

Tawana Brown pose la question : I was uncertain as to whether a number such as 85.25 rounding to the nearest tenth would be 85.3 or 85.2. I thought I had heard somewhere that if 5 is the last number that you don't round up. But I have also heard that anything 5 and above you do round up. It's been awhile since I've done rounding, so I need a refresher course. Walter Whiteley and Harley Weston lui répond. 





Estimates 
20000411 

Sue Jordan pose la question : I am looking for examples of estimates for underestimating and overestimating. When would you do each one. For my child age 11 6th grade. Penny Nom lui répond. 





Approximations 
19991220 

Adrian Valc pose la question : Longtime ago I red an article about surprizing (and in a way frustrating) results in math, for example the limit of a nicely defined infinite series which was believed to be a simple rational number, but later was determined to be a transcendent number that missed the rational value by an incredibly small amount (so for example the limit proved to be 2.75000...00137.. with a lot of 0's in between). I cannot find that article anymore, so i was wondering if you have any such examples, or you can point to any relevant information source? Chris Fisher lui répond. 





Two calculus problems 
19991213 

Alan pose la question : I have 2 questions that are very new to me, they were included on a quiz and the material was never covered. Our teacher never explained the purpose and detailed explanation of how to solve the problem. Could you help? Thanks. Question 1: A ball is falling 30 feet from a light that is 50 feet high. After 1 sec. How fast is the shadow of the ball moving towards the light post. Note that a ball moves according to the formula S=16t^2 Question 2: How many trapezoids must one use in order for the error to be less than 10^8 if we want to find the area under the curve Y=1/X from 1 to 2. Find the exact area, Graph the function and use the trap rule for the "N" that you found. Harley Weston lui répond.






Calculating a square root 
19991028 

Jonathan pose la question : What is the formula for calculating a square root? Penny Nom lui répond. 





Square roots without a calculator 
19990914 

Josh Weiner pose la question : Is there any way to find out a square root without a calculator? Harley Weston lui répond. 





The bricklayers formula 
19981124 

Rachel Kaplan pose la question : I have to do a report on the bricklayers formula N = 7LH. Can you give me any information on this. Harley Weston lui répond. 





Radicals 
19980915 

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 fortyfive, 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. 





Approximating pi. 
19961104 

Ben Dixon pose la question : How do you calculate Pi? Do you have to somehow combine the equation for a circle with the formula for the circumference? Chris Fisher lui répond. 





Approximating roots. 
19961104 

Ben Dixon pose la question : How do you calculate a square root? eg the square root of 2.There is obviously some sort of successive approximation type algorithm for doing it to however many decimal places is required, but what is the algorithm? Harley Weston lui répond. 

