Thread: Help with word problems please

A can is to be constructed in the form of a right circular cylinder. If it is to contain 128 , what dimensions will require the least amount of material.

This is what I did:


solved for h

since

so

graphed it to find the min., but what I got requires r = 0, which can't be right?

Originally Posted by ggeek101

A can is to be constructed in the form of a right circular cylinder. If it is to contain 128 , what dimensions will require the least amount of material.

This is what I did:


solved for h

since

so

graphed it to find the min., but what I got requires r = 0, which can't be right?

redo your graph ... mine shows the minimum to be close to r = 4