The function is
.
Increasing and decreasing function :
\1. If
for all
in
, then
is decreasing on
.
2. If
for all
in
, then
is increasing on
.

Apply derivative on each side with respect to
.

Equate it to zero to find the critical numbers.
\
The critical number is
.
Consider the test intervals to find the interval of increasing and decreasing.
\Test intervals are
and
.
| Test interval | \Test value | \Sign of ![]() | \
Conclusion | \
![]() | \
![]() | \
\
| \
Increasing | \
![]() | \
![]() | \
\
| \
Increasing | \
\
So the function is increasing over the entire interval
.
The function is increasing over the interval
.