$\"\"$

\

The volume of the cone $\"\"$ and $\"\"$ , $\"\"$ .

\

The formula is $\"\"$ .

\

When $\"\"$ , the volume of the cone is $\"\"$ .

\

$\"\"$

\

Apply derivative on each side with respect to $\"\"$ .

\

$\"\"$

\

Power rule of the deivative : $\"\"$ .

\

$\"\"$

\

Substitute $\"\"$ in the above equation.

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

(a).

\

Find the rate of change of volume when $\"\"$ .

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

(b).

\

Find the rate of change of volume when $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

(a) $\"\"$ .

\

(b) $\"\"$ .