You are asked to design a rectangular box with a square bottom with total volume $V$=11 cubic feet. The material:
$2.75 per square foot for the base of the box
$2.50 per square foot for the sides of the box
$0.50 per square foot for the top of the box
What should the height be to minimize the cost of material.
I'm stuck on this problem. I keep following the example that is given in my textbook but for some reason my answer is too high.
Can anybody please help me solve it????