Appendix D - Graphing Techniques - Exercises - Page 447: 59

Refer to the curve in Black in Graph I

For $f(x) = -\sqrt{x}$ when $x = 9, y = -3;$ $x = 4, y = -2;$ $x = 1, y = -1;$ $x = 0, y = 0$ As seen, $f(x) = -\sqrt{x}$ is the reflection across the $x$-axis of $f(x) = \sqrt{x}$. Domain = $[0, \infty)$ Range = $(-\infty, 0]$