A closed rectangular box is built in such a way that its volume
corresponds to 60 cubic feet. The cost of the material for the top
and the bottom are, 10 cents per square foot and 20 cents per
square foot, respectively. The cost of the sides is 2 cents per
square foot.
a.)Determine the cost function where x and y are the length and
width of the box, respectively.
b.)Calculate the dimensions of the box that will produce a
minimum cost.