## Precalculus (6th Edition)

domain: $\left\{3\right\}$ range: $\left\{-\infty, +\infty\right\}$ Refer to the graph below.
RECALL: The line $x=a$, where $a$ is a real number:: (a) is vertical. All points on this line have an x-coordinate of $a$; (b) has the set of real numbers as its range; and (c) has a domain of $\left\{a\right\}$ Thus, the graph of the equation $x=3$ is a vertical line. All points on the line have an x-coordinate of $3$. The domain is $\left\{3\right\}$. The range is $\left\{-\infty, +\infty\right\}$. The line contains the points $(3, 0)$ and $(3, 3)$. Plot the points above and connect them using a line. (Refer to the graph in the answer part above.)