Final answer:
The points (-1,2) and (-1,3) cause the relation to not be a function.
Step-by-step explanation:
A relation is a function if each input value (x-coordinate) is associated with only one output value (y-coordinate). In this given relation, ((-1,2),(2,3),(-1,3),(1,5)), we can see that the points (-1,2) and (-1,3) cause the relation to not be a function.
The point (-1,2) and (-1,3) have the same x-coordinate (-1), but different y-coordinates (2 and 3). This violates the rule that each x-coordinate should only be associated with one y-coordinate in a function.