What will the dimensions of the resulting cardboard box be if the company wants to maximize the volume and they start with a flat piece of square cardboard 20 feet per side, and then cut smaller squares out of each corner and fold up the sides to create the box?

1 Answer
Mar 24, 2015

Suppose that the squares removed from each corner are x feet by x feet each.

When these are folded up they give a box with a height of x feet
and a base of 202x feet by 202x feet
for a volume
V=x(202x)2=400x80x2+4x3

To find the critical point(s) take the derivative of V, set it to zero, and solve for x.

dVdx=400160x+12x2

=4(3x10)(x10)=0

Since x=10 gives a Volume of 0

the critical point for the Volume that is it's maximum occurs when x=103.

The resulting box will be
313×1313×1313 feet