The equations are
,
.
The volume of the solid generated revolving about the
- axis.
Washer method:
\
.
Find the integral limits.
\
,
.

and
.
and
.
and
.
Graph of the equations:
and
on
.
The outer radius of revolution is
.
The inner radius of revolution is
.

Substitute
and
in the formula.





\
.
.