#### Answer

$\text{
NOT a function
}\\\text{Domain: }
(-\infty, 0]
\\\text{Range: }
(-\infty,\infty)$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
Use the vertical line test to determine if the given graph is a function. The domain is the set of $x$-values and the range is the set of $y$-values.
$\bf{\text{Solution Details:}}$
A vertical line drawn at $x=-1,$ will intersect the graph in more than $1$ point. Hence, the given graph is not a function
The $x$-values used in the graph are all numbers less than or equal to $0.$ The $y$-values used in the graph are all real numbers.
Hence, the given set has the following characteristics:
\begin{array}{l}\require{cancel}
\text{
NOT a function
}\\\text{Domain: }
(-\infty, 0]
\\\text{Range: }
(-\infty,\infty)
.\end{array}