## Trigonometry 7th Edition

Refer to Graph I Domain is {$x$ | $x \ge 4$} Range is all real numbers of $y$ The graph is not a graph of function
Refer to Graph I for the graph of $x$ = $y^2$ + 4 (in black color). The domain is {$x$ | $x \ge 4$}. and the range is all real numbers of $y$. By means of vertical line test (in red color), the graph is not a graph of function since at any x-value > 4, the line cuts the graph at more than one y-value.