Determine whether the graph is that of a function by using the vertical-line test. If it is, use the graph to find

The graph belongs to a function, a quadratic function.
The domain is Real numbers:
[tex](-\infty,\infty)[/tex]and the range is
[tex]\begin{gathered} y\ge-4 \\ or\text{ (-4, }\infty) \end{gathered}[/tex]