Originally Posted by

**ilsj6** I understand what you wrote and that is how I solved it, initially. However, my answer just didn't seem right because that is what you would get if you solved it without Calculus. My work:

V = L^2(h)

450 = L^2(h)

h = 450/(L^2)

SA = (2L^2) + (1800L/(L^2))

I took the derivative:

SA' = 4L - (1800/(L^2))

Set it equal to zero and solved for "L:"

0 = 4L - (1800/(L^2))

-4L = - (1800/(L^2))

-4L^3 = -1800

L^3 = 450

L = 7.66

From here, I plugged it back into the volume formula to solve for "h:"

450 = 58.6756h

h = 7.669 = 7.67

Basically, my height, width, and length would approximately be 7.66 inches to minimize the Surface Area.

Is this correct?