# minimizing the cost of making a box with an open top

• Dec 16th 2012, 01:19 PM
OceanicBlue
minimizing the cost of making a box with an open top
a box is made with a square bottom and open top to hold a volume of 8ft3. the material for the sides cost \$4 per square foot and the material for the bottom costs \$1 per square foot. What dimensions will minimize the cost of the box?
• Dec 16th 2012, 01:32 PM
skeeter
Re: minimizing the cost of making a box with an open top
what equations have you come up with from the given problem statement?
• Dec 16th 2012, 02:08 PM
HallsofIvy
Re: minimizing the cost of making a box with an open top
Let "x" be the length of each side of the base and "y" be the height. What is the volume in terms of x and y? What is the total area in terms of x and y?
• Dec 16th 2012, 03:07 PM
OceanicBlue
Re: minimizing the cost of making a box with an open top
how do you solve a volume with 2 variables???
• Dec 16th 2012, 03:21 PM
skeeter
Re: minimizing the cost of making a box with an open top
Quote:

Originally Posted by OceanicBlue
how do you solve a volume with 2 variables???

you come up with two equations ... the object equation (cost) and constraint equation (volume).