The equations are ,
,
and
.
(a) Find the volume about the -axis:
The volume of the solid is .
Substitute ,
and
.
.
The equations are ,
,
and
.
(b) Find the volume about the -axis:
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
.
.
The equations are ,
,
and
.
(c) Find the volume about the :
Shell method:
\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
.
.
The volume of the solid about the -axis is
.
The volume of the solid about -axis is
.
The volume of the solid about is
.
The volumes of the resulting solids from least to greatest is .
Therefore, .
The volumes of the resulting solids from least to greatest is .