The function is 
Differentiate on each side with respect to
.
..
Product rule of derivatives :
.

.
The derivative function is
.
Again differentiate
on each side with respect to
.
.
Product rule of derivatives :
.

.
Find the inflection point by equating
.
.

and
.
Inflection points:
\(a)
at
.
.
Inflection point
.
(b)
at
.
.
Inflection point
.
The test intervals are
,
and
.
| \
Interval \ | \
Test Value | \Sign of ![]() | \
Concavity | \
![]() | \
\
| \
\
| \
up ward | \
![]() | \
\
| \
\
| \
Up ward | \
![]() | \
\
| \
\
| \
Down ward | \
The graph is concave down in the interval
and concave up in the interval
,
.
Inflection point
and
.
The graph is concave down in the interval
.
The graph is concave up in the interval
and
.