The domain is the set of all possible x values:
[tex]D=\{-3, -1, 2, 4, 5\}[/tex]
The range is the set of all possible y values:
[tex]D=\{0, 2, 4, 6\}[/tex]
The relation is a function, because you're associating one y value for each x value (i.e. you're not mapping twice the same x value)
