#### Answer

Concave upward on
$$
(-2, 6).
$$
Concave downward on
$$
(-\infty, -2) \text{ and } (6,\infty).
$$
Inflection points at
$$
(-2,-4) \text{ and } (6,-1).
$$

#### Work Step by Step

Since the graph of the function lies above its tangent line at each point of $(-2, 6)$ .
So, concave upward on
$$
(-2, 6).
$$
Since the graph of the function lies below its tangent line at each point of $(-\infty, -2)$ and $(6,\infty)$ .
So, concave downward on
$$
(-\infty, -2) \text{ and } (6,\infty).
$$
Since a point where a graph changes concavity is $(-2,-4)$ and $(6,-1)$
So, Inflection points at
$$
(-2,-4) \text{ and } (6,-1).
$$