I'm having trouble understanding this problem set, I need help and an explanation to study from please

154. Consider the graph of the function y = f (x) shown in the following graph. y A o 1. /2 -1 o 1 2 X 1+ a. Find all values for which the function is discontinuous. b. For each value in part a., state why the formal definition of continuity does not apply. c. Classify each discontinuity as either jump, removable, or infinite