Question

The rate of change of the volume of a cone with respect to the radius of its base is -

• A. ${\pi }^{2}h$
• B. $\frac{4}{3}\pi rh$
• C. $\frac{4}{3}\pi r^{2}h$
• D. $\frac{2}{3}\pi rh$

Answer 1

Answer: (D)

$V=\frac{1}{3}\pi r^{2}h$
$\Rightarrow \frac{dv}{dr}=\frac{2}{3}\pi rh$