$\"\"$

The function is $\"\"$ .

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

$\"\"$

Again apply derivative on each side with respect to $\"\"$ .

$\"\"$

Substitute $\"\"$ in the above function.

$\"\"$

Observe the second derivative function, $\"\"$ may be any value $\"\"$ .

From the concavity test, $\"\"$ then the function $\"\"$ has a concave up.

Therefore the function $\"\"$ does not have inflection point at $\"\"$ .

$\"\"$

The function $\"\"$ does not have inflection point at $\"\"$ .