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	Two overlapping circles		2010-04-12
		From Scott: There are two circles, big circle with radius R and small one with radius r. They intersect and overlap in such a way that the common area formed is 1/2 pi r^2 (half the area of the small circle). The Question is: suppose we have known the radius r of the small circle, and the distance between the two circle centers, what should the radius R of the large circle be? Answered by Chris Fisher.
	Integrate the ((4th root of x^3)+1) dx		2010-04-12
		From Bridget: integrate the ((4th root of x^3)+1) dx Answered by Tyler Wood.
	Volume of a cylinder		2010-04-12
		From Louis: A hockey puck has a diameter of 7.5 cm and a thickness of 2.5 cm. What is its Volume? A copper pipe with an inside diameter of 1cm. is 4m long. What volume of water (in cm3) can it hold? Answered by Tyler Wood.
	6 items are taken 3 at a time		2010-04-12
		From Kristen: Explain the three different scenarios that could occur and would result in the following number of outcomes when 6 items are taken 3 at a time. Give real-life examples. a. 63 = 6 x 6 x 6 = 216 possibilities b. 6! / (6 - 3)! = 6 x 5 x 4 = 120 possibilities c. 6! / (6 - 3)! 3! = 20 possibilities Answered by Tyler Wood.
	A rectangle problem		2010-04-12
		From Charlene: The ratio of the width to the length of a certain rectangle is equal to the ratio of its length to the difference between its length and twice its width. If the area of the rectangle is 25cm^2, then what are its dimensions? Present a non- algebraic solution? Answered by Tyler Wood.
	The perimeter of a rectangle		2010-04-12
		From Charlene: The area of a rectangle is 390m^2. If its length is increased by 10m and its width is decreased by 6m, then its area does not change. Find the perimeter of the original rectangle. Answered by Tyler Wood.
	Vapor trails		2010-04-12
		From Frank: I'm not sure if this is a proper question to ask so if I have misdirected my question I apologize and no response is expected. I am trying to figure out a way to measure vapor trails from my back yard in Phoenix Arizona. If I used a compass and spread each point of the compass to the start and finish of the vapor trail I would have the angle of an isosceles triangle. The other two angles would be identical. The height of from the inverted base of the triangle to my standing spot on the ground would be about 35,000 feet. I'm thinking that there should be a way to figure out the length of the inverted base (vapor trail) but I'm devoid of mathematical skills and can't seem to figure out how to do this. Is it possible to figure out the length of a vapor trail using this method or do you have an easier way to accomplish the task? Any help you could offer would be most appreciated. Thanks....Frank Answered by Harley Weston.
	4 books at the book fair		2010-04-11
		From Erin: You have enough money to buy 4 books at the book fair. There are 6 books to choose from. How many different combinations are there. Answered by Tyler Wood.
	Exactly two lines of symmetry		2010-04-11
		From debbie: i am looking for a quadrilateral with exactly two lines of symmetry. please help! thank you. Answered by Tyler Wood.
	Two max/min problems		2010-04-11
		From Amanda: 1) Find the area of the largest isosceles triangle that canbe inscribed in a circle of radius 4 inches. 2)a solid is formed by adjoining two hemispheres to the end of a right circular cylinder. The total volume of the solid is 12 cubic centimeters. Find the radius of the cylinder that produces the minimum surface area. Answered by Tyler Wood.
	A cube with twice the volume		2010-04-11
		From Woojin: From a given cube create another cube with twice the volume. the cube: 5cm each. Answered by Tyler Wood.
	Working backwards		2010-04-11
		From adel: alice gave reggie and freddie as much money as each had already.reggie in turn gave alice and friddie as much money as each already had in negotiable treasury notes. freddie gave alice and reggie as much money as they each had. in the end they each had the same sum, 24000.00.how much money did they each in the beginning? Answered by Penny Nom.
	One red ball and one black ball		2010-04-11
		From Sammy: The probability of drawing a red ball out of a bag containing one red ball and one black ball is ½. An experiment is conducted where these two balls are placed in a bag before drawing a ball out. A ball is drawn five times from the bag containing the two balls. Each of the first five times the red ball was drawn out. What is the probability that the sixth draw will be a red ball? Explain your answer. Answered by Penny Nom.
	The median		2010-04-10
		From Ayssa: The median of the data set (24, 35, 30, 12, 40, x) is 28. What is the value of x? Answered by Robert Dawson and Penny Nom.
	The derivative of y=x^x		2010-04-09
		From David: So, its David, and I was wondering about the derivative of y=x^x. I have often seen it be shown as x^x(ln(x)+1), but when I did it through limits it turned out differently. Here's what I did: It is commonly know that df(x)/dx of a function is also the limit as h->0 of f(x+h)-f(x)/h. To do this for x^x you have to start with lim h->0 ((x+h)^(x+h)-x^x)/h. The binomial theorem then shows us that this is equal to lim h->0 (x^(x+h)+(x+h)x^(x+h-1)h+...-x^x)/h This is also equal to lim a->0 lim h->0 (x^(x+a)+(x+h)x^(x+h-1)h...-x^x)/h. Evaluating for a=0 you get lim h->0 (x^x+(x+h)x^(x+h-1)h...x^x)/h Seeing as the last 2 terms on the numerator cancel out you can simplify to a numerator with h's is each of the terms, which you can then divide by h to get: lim h->0 (x+h)x^(x+h-1)... which when evaluated for h=0 gives us: x(x^(x-1)). This statement is also equal to x^x. This contradicts the definition of the derivative of x^x that is commonly shown. So, my question is: can you find any flaws in the logic of that procedure? I do not want to be shown how to differentiate x^x implicitly because I already know how to do that. Answered by Robert Dawson.

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