It is not a function because the points are not connected to each other.
It is not a function because the points are not related by a single equation.
It is not a function because there are two different x-values for a single y-value.
It is not a function because there are two different y-values for a single x-value.
Answer: It is not a function because there are teo different y-values for a single x-value.
A graph would not be a function if there were two different y-values for one x-value. According to the Rule Book, a graph cannot be a function if the x-values repeat.
