(i)[2]
Show that the cone’s volume, $V\text{ cm}^3$, can be written as $V = \frac{1}{3}\pi(225h - h^3)$. [For a cone with radius $r$ and vertical height $h$, the volume is $\frac{1}{3}\pi r^2 h$.]
(ii)[5]
Given that $h$ may change, determine the value of $h$ for which $V$ is stationary. Show all required working and state the nature of this stationary value.