The function is
.
Differentiate with respect to
.

Again differentiate with respect to
.



To find the intervals of increase and decrease, set
.

cannot be equated to zero.

Therefore intervals are
and 
Consider a test point from the interval
.
Let
in
.
then
is decreasing in the interval
.
Consider a test point from the interval 
Let
in
.
then
is increasing in the interval
.
Therefore,
\
is decreasing in the interval
and increasing in the interval
.
To find the inflection points, set
.

cannot be equated to zero.

Substitute
in 


Inflection point is
.
The test intervals are
and
.
Interval Test Value Sign of f(x) Conclusion
\
Concave upward
Concave downward
(a)
is decreasing in the interval
and increasing in the interval
.
(b) Inflection point is
.
(c)
is concave up in the interval
and concave down in the interval
.