Answer
Function
The domain is $(-\infty, 1]$.
The range is $[-1, +\infty)$.
Work Step by Step
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 $[-1, +\infty)$.
