We will have the following:
First, we are given:

Now, we determine the critical points:

So, we can see that the expression has two critical points at x = 3 & x = 9.
So, at the points:

&

Now, we determine which one is the inflection point as follows:

So, we analyze the function at the points given:
*x = 3:

So, at x there is a local minimum.
*x = 9:

So, at x = 9 there is a local maximum.
The expression given has no inflection point.