Cost of Cylinder Can holding 4 pi cubic inches of juice

[Becky4paws]

A cylindrical can is to hold 4 pi cubic inches of frozen juice. The cost per square inch of constructing the metal top and bottom is twice the cost per square inch of constructing the cardboard side. What are the dimensions of the least expensive can?

C = cost of the side + 2(cost of the side for top) + 2(cost of the side for bottom)

V = 4pi(r^2)h
h = v/4pi(r^2)

Where do I go from here?

 

[tkhunny]

Re: Cost of Cylinder Can

A cylindrical can is to hold 4 pi cubic inches of frozen juice. The cost per square inch of constructing the metal top and bottom is twice the cost per square inch of constructing the cardboard side. What are the dimensions of the least expensive can?

C = cost of the side + 2(cost of the side for top) + 2(cost of the side for bottom)

V = 4pi(r^2)h
h = v/4pi(r^2)

Where do I go from here?

First, you're not making much sense, but it is easily repaired.

C = cost of the side + cost for top + cost for bottom

V = pi(r^2)h

Area of Top = Area of Bottom = pi(r^2)

Area of Side = Lateral Surface Area = 2*pi*r*h

x = Cost/in^2 of cardboard sides

Cost of Side = (Area of Side) *x

Cost of Top = Cost of Bottom = (2*(Area of Top)) * (2x)

Do not be afraid to write things down. Do not try to do it all in your head. Let the notation help you.