As a preparation for the long bright summer days, Dr. Acula plans to store gourmet plasma in closed tin cans that have the shape of a cylinder with volume $V$. As an environmentally conscious member of the community, he wants to use as little metal as possible.

a. What is the height $h(r)$ for the can with minimum surface area in terms of the radius $r$ of the bottom?
$h(r)=$
b. What is the minimum surface area for the can in terms of the portion size $V$ ?
$A_{\text{min}}(V) =$