$\"\"$

\

The function is $\"\"$ .

\

$\"\"$ .

\

Apply derivative on each side with respect to $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Apply second derivative on each side with respect to $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

To finc inflection points, substitute $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Take logarithm on each side.

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

$\"\"$

\

Therefore, the intevals are $\"\"$ and $\"\"$ .

\

Consider the test point as $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .

\

Hence the function is concave downward in the interval $\"\"$ .

\

Consider the test point is $\"\"$ .

\

Consider the test point as $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .

\

Hence the function is concave upward in the interval $\"\"$ .

\

$\"\"$

\

The function $\"\"$ is concave downward in the inerval $\"\"$ .