







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 positive root of sin(x) = x^2 
20151213 

Kemboi pose la question : Find the positive root of the equation sin(x) = x^2 Penny Nom lui répond. 





2^x . 5^3 = x^4 
20130905 

Zuhdina pose la question : Hi, I got a question, 2^x . 5^3 = x^4
I want to know the value of x without using calculator, I've already done some questions in logarithm and I always stuck in the same model equationI think if someone shows me the way, I can do the other 'stuck equations' 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. 





Compatible numbers 
20080925 

Katie pose la question : I am having trouble remembering how to find compatible numbers used to find the estimate in the foloowing problem. Can you please help me solve it and explain it to me? My son is in 5th grade and I need help. Thank you. Here is the problem: 2,752 / 28 estimate: 90 Penny Nom 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 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. 





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. 





As close to 841 as possible 
20060621 

Alan pose la question : using these numbers by either add subtract division multiply come up with the answer as close to 841
100 25 10 7 6 3 Paul Betts 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. 





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. 





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. 





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. 





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.






Spreading a rumor 
19990913 

Bornstar14 pose la question : There is someone who wants to spread a rumor within 7 days to 250,000,000 people. he wants to know how many people he should tell on the first day (assuming the rumor is passed by everyone who was told to the same amount of people) so that everyone knows on the 7th day. What I did is the 7th root of 250,000,000. this answer is not possible unless rounded. is it okay for the number to be approximate? Penny Nom lui répond. 





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. 

