## Precalculus (6th Edition)

The given relation does not represent $y$ as a function of $x$. domain: $[0, +\infty)$ range:$(-\infty, +\infty)$
RECALL: Vertical Line Test If all vertical lines will pass through the graph of a relation in at most one point only, then the relation defines $y$ as a function of $x$. To know if the given graph represents $y$ as a function of $x$, perform the vertical line test. Note that a number of vertical lines (e.g., $x=1$) will pass through the given graph at two points . This means that the graph fails the vertical line test. Thus, the given relation does not represent $y$ as a function of $x$. The graph covers the x-values that are greater than or equal to zero so the domain is $[0, +\infty)$. The graph covers all y-values so the range is $(-\infty, +\infty)$.