f5 M1 招maths master解答 (2)

A container(without lid) consist of a hollow hemisphere of radius r cm joined to the bottom of a right circular cylindrical pipe of base radius r cm.It is known that the area of the outer surface of the container is 162pi cm^2

A) Prove that the capacity of the container is:

(81pi r - [(pi r^3) / 3] cm^3

B) as r vaires,can the capacity of the container be greater than 1600cm^3?explain