Explanation:
this is only asking about the functional values.
in what intervals are the functional values going up (when increasing x from left to right), and in what intervals is the functional value going down (again, when increasing x from left to right) ?
and so we see in the graph,
it is increasing (y-values are going up) in
(-infinity, -1], (2, +infinity)
it is decreasing (y- values are going down) in
(-1, 2]
please consider the used types of brackets.
"(", ")" means the corresponding interval end is NOT included.
"[", "]" mags the corresponding interval end is included.
"infinity" is only a concept and not a value, so it can never be included.
and I wanted the intervals to have no overlap. so, I included "-1" in one and excluded it in the connecting interval. the same for "2".
but if your teacher prefers to have the interval ends overlapping, then please change these brackets to "[" as needed. it all depends on what your teacher defined for you.