Answer:
{ - 1, 2, 3 }
Step-by-step explanation:
The outputs are the y values of the points corresponding to the red dots.
That (- 2, - 1) and (2, - 1) have output y = - 1
(- 3, 2 ) has output y = 2
(3, 3 ) has output y = 3
The set of outputs is { - 1, 2, 3 }