\
(a)
\Thu function is ,
.
Differentiate on each side with respect to
.
Find the critical points.
\Thus, the critical points exist when .
Equate to zero:
The general solution of cosine function is , where
The solution for is
,
.
and
and
.
The critical points are and
and
.
The test intervals are and
.
Interval | \Test Value | \Sign of ![]() | \
Conclusion | \
![]() | \
![]() | \
\
| \
Increasing | \
![]() | \
![]() | \
\
| \
Increasing | \
The function is increasing over the interval .
\
(b)
\Find the local maximum and local minimum.
\Since the function is increasing, therefore it has neither local maximum nor minimum.
\\
(c)
\.
Differentiate on each side with respect to
.
Find the inflection points.
\Equate to zero.
The general solution of sine function is , where
.
The solution for is
,
.
,
and
.
The inflection points are at ,
and
.
Substitute in
.
Substitute in
.
Substitute in
.
The test intervals are ,
,
and
.
\
Interval \ | \
Test Value | \Sign of ![]() | \
Concavity | \
![]() | \
![]() | \
\
| \
Up | \
![]() | \
![]() | \
\
| \
\
Down \ | \
![]() | \
![]() | \
\
| \
\
Up \ | \
![]() | \
![]() | \
\
| \
Down | \
The graph is concave up on the intervals and
.
The graph is concave down on the intervals and
.
The inflection points are ,
and
.
\
(d)
\Graph :
\Graph the function :
\
(a)
\The function is increasing over the interval .
(b)
\There is neither local maximum nor local minimum.
\(c)
\Concave up in the intervals and
.
Concave down in the intervals and
.
Inflection points are ,
,
,
and
.
(d)
\Graph of the function is
.