(a)
\The function is ,
.
Differentiate on each side with respect to
.
Find the critical points.
\Equate to zero:
and
and
and
.
The critical points are and
.
The test intervals are ,
and
.
Interval | \Test Value | \Sign of ![]() | \
Conclusion | \
![]() | \
![]() | \
\
| \
Decreasing | \
![]() | \
![]() | \
\
| \
Increasing | \
![]() | \
![]() | \
\
| \
Decreasing | \
The function is increasing on the interval .
The function is decreasing on the intervals and
.
(b)
\Find the local maximum and local minimum.
\The function has a local minimum at
, because
changes its sign from negative to positive.
Substitute in
.
Local minimum is .
The function has a local maximum at
, because
changes its sign from positive to negative.
Local maximum is .
(c)
\.
Differentiate on each side with respect to
.
Find the inflection points.
\Equate to zero.
and
and
The values of for
on
is
and
.
The values of for
on
is
.
not consider as the inflection point since it is critical point.
The inflection point is and
.
The test intervals are ,
and
.
\
Interval \ | \
Test Value | \Sign of ![]() | \
Concavity | \
![]() | \
![]() | \
\
| \
Down | \
![]() | \
![]() | \
\
| \
Up | \
![]() | \
![]() | \
\
| \
\
Down \ | \
The graph is concave up on the interval .
The graph is concave down on the intervals and
.
Inflection points :
\Substitute in
.
Substitute in
.
The inflection point are and
.
\
(a)
\Increasing on the interval .
Decreasing on the intervals and
.
(b)
\Local maximum is .
Local minimum is .
(c)
\Concave up on the interval .
Concave down on the intervals and
.
Inflection points are and
.