The function is
.
Find the critical numbers by applying derivative .
\
Equate it to zero .
\
Therefore the critical numbers are
and
.
Test intervals are
,
and
.
| Test intervals | \ \
Test value \ | \
\
Sign of | \
Conclusion | \
![]() | \
![]() | \
\
| \
Decreasing | \
![]() | \
![]() | \
\
| \
Increasing | \
![]() | \
![]() | \
\
| \
Decreasing | \
So the function
is decreasing on the intervals
and
.
The function
is increasing on the interval
.
The function
is decreasing on the intervals
and
.
The function
is increasing on the interval
.