Step 1:

The volume of solid integral is $\"\"$ .

Volume of the solid, obtained by rotating about $\"\"$ -axis,

the region under the curve $\"\"$ from a to b is

$\"\"$

Re-write the expression.

$\"\"$

Compare the above expression with volume of the solid,

$\"\"$ , $\"\"$ and $\"\"$ .

Solid obtained by rotating the region $\"\"$ about $\"\"$ -axis.

Solution :

Solid obtained by rotating the region $\"\"$ about $\"\"$ -axis.