Work Step by Step
This is the point because if the relation is not a function then it does not pass the vertical line test or there can be 2 different range values for exactly 1 domain value. (1,1) is the point because there is also another value for the domain value of 1 in the graph which is -1. If we plot this point and we were to draw a vertical line through this point we would hit the other point that also shares the domain value. Therefore we need a point that already has its x-value being used for another point in order to make the relation not a function.