## Precalculus (10th Edition)

Not a function. Domain: $\{-4, -3, -2, -1\}$ Range:$\{0, 1, 2, 3, 4\}$
A relation is a function if for all $x$ values there is exactly one corresponding $y$ value. The domain is the set of values the function can take and the range is the set of values which the function “produces” from the values of the domain. The given relation is not a function because for each value in the first set, there is not always (e.g. for $-4$) only one corresponding value in the second set. Domain: $\{-4, -3, -2, -1\}$ Range:$\{0, 1, 2, 3, 4\}$