The function is
,
.
Apply first derivative with respect to
.

Find the relative extrema, by equating
.




The general solution of sine function
is
.
Where 
Then, 
Substitute
in
.


Substitute
in
.



Substitute
in
.



Substitute
in
.



Therefore
and
are the solution in the given interval.
So the critical values of
are
and
.
Now, substitute
in
.

Now, substitute
in
.

The relative extrema points are
and
.
Using the second derivative test.
\Apply second derivative with respect to
.


| Point | \![]() | \
![]() | \
Sign of ![]() | \
\
| \
\
| \
| Conclusion | \Neither | \Neither | \
Therefore
does not have any relative extrema.