The equations are
,
,
and
.
Find the volume of the region about the
-axis.
The volume of the solid is
.
Substitute
,
and
.


.
The equations are
,
,
and
.
Shell method:
\Vertical axis of revolution.
\The volume of the solid is
.
The distance from the center of the rectangle to the axis of revolution is
.
The height of the rectangle is
.
Substitute
,
and
and
in
.



.
Solve for
, when
.
Substitute
and
.






or 

.
Therefore , the value of
.
The value of
.