help with this calc question?

A proposed new grain silo consists of a cylinder of height h and radius r, capped by a hemisphere. Express its volume as a function of h and r.

Cylinder = π r^2 h Half a sphere = 1/2 (4/3 π r^3) = 2/3 π r^3 so V = π r^2 h + 2/3 π r^3