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

Equate the derivative to
.

Therefore the critical number is
.
(b)
\Consider the test intervals to find the interval of increasing and decreasing.
\Test intervals are
and
.
| Test interval | \Test value | \Sign of ![]() | \
Conclusion | \
![]() | \
![]() | \
\
| \
Increasing | \
![]() | \
![]() | \
\
| \
Decreasing | \
The function
is increasing on the interval
.
The function
is decreasing on the interval
.
(c)
\Use first Derivative Test to identify all relative extrema.
\
changes from positive to negative . [From (b) ]
Therefore according to First derivative test , the function has maximum at
.
The function
has a relative maximum at
.
Find
.

So the function
has relative maximum at
.
(d)
\Graph the function is
.

Observe the graph :
\The function has critical number at
.
The function
is increasing on the interval
and decreasing on the interval
.
The function
has relative maximum at
.
(a) The function has critical number at
.
(b) The function
is increasing on the interval
and decreasing on the interval
.
(c) The function
has relative maximum at
.
(d) Graph of the function
is \ \
