Posted by Anonymous on Sunday, January 23, 2011 at 10:06pm.
A rectangular box is to have a square base and a volume of 50 ft3. The material for the base costs 44¢/ft2, the material for the sides costs 10¢/ft2, and the material for the top costs 26¢/ft2. Letting x denote the length of one side of the base, find a function in the variable x giving the cost (in dollars) of constructing the box.

calculus  Reiny, Sunday, January 23, 2011 at 10:14pm
let each side of base be x
let the height be y
x^2y = 50
y = 50/x^2
cost = 44x^2 + 4(10)(xy) + 26x^2 , where cost is in cents
=70x^2 = 40x(50/x^2)
= 70x^2 + 2000/x 
calculus  Anonymous, Sunday, January 23, 2011 at 11:23pm
which one is the answer?

calculus  Damon, Monday, January 24, 2011 at 5:32am
The question asked for the cost.

calculus  Danny, Wednesday, January 23, 2013 at 7:13pm
Damon the answer is wrong.