
(i) If $\mathrm{r} \mathrm{cm}$ be the radius and $\mathrm{h} \mathrm{cm}$ be the height of the cylindrical tin can, then express the surface area as a function of radius (r)
(ii) Find the radius of the can that will minimize the cost of tin used for making can?
(iii) Find the height that will minimize the cost of tin used for making can ?
OR
Find the minimum cost of material used to manufacture the tin can.
