#### Problem 74E

74. The volume of a right circular cone is $V=\frac{1}{3} \pi r^{2} h$, where $r$ is the radius of the base and $h$ is the height.

(a) Find the rate of change of the volume with respect to the height if the radius is constant.

(b) Find the rate of change of the volume with respect to the radius if the height is constant.

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