## Precalculus (6th Edition) Blitzer

Function The domain is $(-\infty, 1]$. The range is $[-1, +\infty)$.
All vertical lines will pass through the graph in at most one point. Thus, the graph represents a function. The graph covers all the x-values from $1$ to its left, therefore the domain is $(-\infty, 1]$. The graph covers all the y-values from $-1$ and above therefore, the range is $[-1, +\infty)$.