the polynomial function is

The graph appears to show a polynomial function of the third degree with two real roots. The minimum point of the graph is at (-2,-4), which means the quadratic factor of the function must be
. The two real roots must be to the left of -2, so we can write the polynomial as
. To determine the values of a and b, we can use the fact that the graph passes through the points (-4,4) and (4,2).
When x=-4, the function is evaluated as
. We know that f(-4)=4, so
. Solving for a, we get
.
When x=4, the function is evaluated as
. We know that f(4)=2, so 16a(6-b)=2. Solving for a, we get

Setting these two expressions for a equal to each other, we get
. Solving for b, we get b=3.
Therefore, the polynomial function is
.