Answer:
There is a local maximum at the point (-1,6), therefore, for x = -1
Explanation:
Notice that the function adopts values smaller than 6 to the left of x = -1, and to the right of it:
(-3, -2), (-2, 0) to the left of x = -1 where the function's value is 6
and (0, 0), and (1, -2) to the right of x = -1
therefore, it looks like (-1, 6) is a maximum, that is for x = -1, where the function renders a value of 6.