# Thread: Maximizing volume of a box help

1. ## Maximizing volume of a box help

Problem: if 1200cm^2 of material is available to make a box with a square base and an open top, find the largest possible volume of the box
Heres what I did
area = 1200cm^2
total area = area of the 5 sides of the box(5 since it says an open top)
area of one side = xy
total area = 1200=5xy
x=240/y
volume =xy^2
v=240y(y^2)
V=240y
V'=240....
which doesn't work because I think to find the maximum, you have to solve where the derivative is 0
is there another strategy or did I make some basic mistake

2. The area isn't correct.

"a box with a square base"

It should be: $1200 = x^2 + 4xy$