Determining if a Relation is a Function

A mapping diagram illustrates how each element in the input is paired with an element in the output. An ordered pair is a set of numbers written in the form $(x,y),$ where $x$ is a number from the input and $y$ is a number from the output.

Looking at where the arrows start and end, we can see the $x$-coordinates and their corresponding $y$-coordinates. We get the ordered pairs by pairing these values. $$\begin{array}{c}(\text{-}6,5),(\text{-}5,8),(1,0),(2,8)\end{array}$$