# Calculus AB

posted by
**Rahul**
.

The volume V or a cone (V = 1/3 π r² h) is increasing at a rate of 28π cubic units per second. At the instant when the radius r of the cone is 3 units, its volume is 12π cubic units and the radius is increasing at 0.5 unit per second.

a) At the instant when the radius of the cone is 3 units, what is the rate of change of the area of its base? (I got 3π)

b) At the instant when the radius of the cone is 3 units, what is the rate of change of its height h?

c)At the instant when the radius of the cone is 3 units, what is the instantaneous rate of change of the area of its base with respect to its height h?

For A I got 3pi

For B I got 8

What do i do for C? and what answer should I get?