The functions are
and
on
.
The volume of the solid generated revolving about the
- axis.
on interval
.
Since
, he outer radius of revolution is
and the inner radius of revolution is
.
Formula for the volume of the solid with the Washer method,
\
.
Substitute
and
in
.
.
Therefore, the volume of the solid represents integral is option (b).
\Option (b) is correct choice.