A square sheet of cardboard 18 inches is made into an open box (there is no top), by cutting squares of equal size out of each corner and folding up the sides. Find the dimensions of the box with the maximun volume.

Volume= base(width)height

but base + 2H =18
base + 2W=18

since squares are cut out of the corners, base and width are the same.

Volume=base^2 * height

but height= 9 - base/2
Volume = base^2 (9-base/2)

differentiate, set to zero, solve.

oooops you are in precal. If you don't know how to differentiat a uv function, then
graph this function for max volume.

x^4+6<5X^2

1 answer

-18X

The maximum volume of the box is when the base is 6 inches and the height is 3 inches.