## Precalculus (6th Edition)

The given relation defines a function. domain: $\left\{2010, 2011, 2012, 2013\right\}$ range: $\left\{63.0, 63.5, 64.9, 65.1\right\}$
RECALL: A function is a relation whose every first coordinate is paired with only one second coordinate. In the given relation, every first coordinate $(x)$ is paired with only one second coordinate $(y)$. Thus, the given relation defines a function. The domain is the set of values of $x$ so the domain is: $\left\{2010, 2011, 2012, 2013\right\}$ The range is the set of values of $y$ so the range is: $\left\{63.0, 63.5, 64.9, 65.1\right\}$