A cylinder holds 4 pie cubic inchescost per square inch of c
A cylinder holds 4 pie cubic inches.cost per square inch of constructing top and bottom is twice the cost per sq inch of sides.What are the dimensions of then least expensive can?  12 ounces,is approx 6.89 pie inches cubed...
Solution
radius = r, height = h
 volume V = r2h = 4, so h = 4/r2
Cost C = 2(2r2) + 2rh = 4r2 + 2r * 4/r2 = 4(r2 + 2/r)
dC/dr = 4(2r - 2/r2) = 0, so r = 1
h = 4
answer: radius = 1 in, height = 4 in

