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 .