## Precalculus (6th Edition)

RECALL: (1) The slope-intercept form of a line's equation is $y=mx+b$ where $m$=slope and $(0, b)$ is the line's y-intercept. (2) The slope is the ratio rise (change in $y$) over run (change in $x$). The equation $y=\frac{1}{3}x$ has a slope of $\frac{1}{3}$ and a y-intercept of $(0, 0)$. The given function can be written as $y=x.$ This equation has a slope of $1$ and a y-intercept of $(0, 0)$. To graph the equation, perform the following steps: (1) Plot the y-intercept $(0, 0)$. (2) Use the slope to plot another point. From $(0, 0)$, move 1 unit up (the rise) and 1 unit to the right (the run) to reach $(1, 1)$. Plot $(1, 1)$. (3) Complete the graph by connecting the points using a straight line. (Refer to the graph in the answer part above.)