(a)
\The function is
.
Find the critical numbers by applying derivative.
\
.
Apply derivative on each side with respect to
.

.
Equate
to
.

and 
and
.
Critical numbers are
and
.
(b)
\Consider the test intervals to find the interval of increasing and decreasing.
\Critical points are
and
.
The test intervals are
,
and
.
| Interval | \Test Value | \Sign of ![]() | \
Conclusion | \
![]() | \
![]() | \
\
| \
Increasing | \
| \
| \
![]() | \
\
| \
Decreasing | \
![]() | \
![]() | \
\
| \
Increasing | \
The function is increasing on the intervals
and
.
The function is decreasing on the interval
.
(c)
\First derivative test to identify all relative extrema.
\From the first derivative test the function
changing from positive to negative at
. [ from (b)]
has a relative maximum at
.

So the function
has relative maximum at
.
From the first derivative test the function
changing from negative to positive at
. [ from (b)]
has a relative minimum at
.

So the function
has relative minimum at
.
(d)
\Graph :
\Graph the function
:
(2).gif\")
Observe the graph :
\The function has critical numbers at
and
.
The function
is increasing on the intervals
,
and decreasing on the interval
.
The function
has relative maximum at
and
.
(a) The function has critical numbers at
and
.
(b) The function
is increasing on the interval
and
and decreasing on the interval
.
(c) The function
has relative maximum at
.
The function
has relative minimum at
.
(d) Graph of the function
is
.