The equations of the graphs are ,
and
.
(a)
\Find the area of the region.
\Find the integral limits by equating two curve equations.
\.
Area of the region bounded by ,
,
and
.
Consider and
.
The two curves on interval
.
The area enclosed by the curves is .
.
Solve the integral using integration by parts.
\Formula for integration by parts:.
Here and
.
Consider .
Apply derivative on each side with respect to .
.
Consider .
Apply integral on each side.
\.
Substitute corresponding values in .
.
The area of the region is .
(b)
\Find the volume of the solid generated by revolving the region about the -axis.
The volume of the solid generated revolving about the - axis.
Formula for the volume of the solid with the Washer method,
\.
The outer radius of revolution is .
The inner radius of revolution is .
Solve the integral using integration by parts.
\Formula for integration by parts:.
Here and
.
Consider .
Apply derivative on each side with respect to .
.
Consider .
Apply integral on each side.
\.
Substitute corresponding values in .
Again apply integration by parts.
\.
The volume of the solid generated by revolving the region about the -axis is
.
(c)
\Find the volume of the solid generated by revolving the region about the -axis.
The volume of the solid generated revolving about the -axis is
.
Here and
.
Solve the integral using integration by parts.
\Formula for integration by parts:.
Here and
.
Consider .
Apply derivative on each side with respect to .
.
Consider .
Apply integral on each side.
\.
Substitute corresponding values in .
.
The volume of the solid generated by revolving the region about the -axis is
.
(d)
\Find the centroid of the region.
\Moments and center of mass of a planar lamina:
\Let and
be continuous functions such that f
on
, and consider the planar lamina of uniform density
bounded by the graphs of
and
.
The moments about the -and
-axis are
.
.
The center of mass is
and
, where
is the mass of the lamina.
Substitute ,
,
and
in
.
Substitute .
.
.
Substitute ,
,
and
in
.
Substitute .
.
.
The centroid of the region is .
(a) The area of the region is .
(b) The volume of the solid generated by revolving the region about the -axis is
.
(c) The volume of the solid generated by revolving the region about the -axis is
.
(d) The centroid of the region is .