The equations are
,
and
.
(a)
\(1) Draw the coordinate plane.
\(2) Graph the functions
,
and
.
.gif\")
When we rotate a thin horizontal strip as shown in the figure about the
axis, we get a disc with radius
.
The width of the disc is
.
The volume of the solid of revolution is
.
Find volume integrate
to
.
Substitute the values in the equation.
\
Apply integration :
\
(b)
\(1) Draw the coordinate plane.
\(2) Graph the functions
,
and
.

When we rotate a thin horizontal strip as shown in the figure about the
axis, we get a washer
with inner radius
and outer radius
.

Squaring on both sides.
\
.
The width of the washer is
.
Volume of the washer is
.

Find volume integrate
to
.
.
Apply integration:
\
(C)
\(1) Draw the coordinate plane.
\(2) Graph the functions
,
and
.

When we rotate a thin horizontal strip as shown in the figure about the line
, we get a radius
.

Squaring on both sides.
\
.
The width of the disc is
.
Volume of the disc is
.

Find volume integrate
to
.


(d)
\(1) Draw the coordinate plane.
\(2) Graph the functions
,
and
.
.gif\")
When we rotate a thin horizontal strip as shown in the figure about the line
we get a washer with inner radius
and outer radius
.

Squaring on both sides.
\
.
The width of the disc is
.
Volume of the washer is
.

Find volume integrate
to
.



(a)
.
(b)
.
(c)
.
(d)
.