## Intermediate Algebra for College Students (7th Edition)

$y-0=\displaystyle \frac{1}{2}(x-2) \qquad$ ... point-slope form $y=\displaystyle \frac{1}{2}x -1 \qquad$ ... slope-intercept form $f(x)=\displaystyle \frac{1}{2}x -1$ $\qquad$ ... function notation
$(x_{1},y_{1})=(2,0) \; \quad$ (the y-intercept), $(x_{2},y_{2})=(0,-1)\quad$ (the y-intercept) $m=\displaystyle \frac{y_{2}-y_{1}}{x_{2}-x_{1}}=\frac{-1-0}{0-2}=\frac{-1}{-2}=\frac{1}{2}$. So with $m=\displaystyle \frac{1}{2}$ and $(x_{1},y_{1})=(2,0)$, we write the point-slope form $y-y_{1}=m(x-x_{1})$ $y-0=\displaystyle \frac{1}{2}(x-2) \qquad$ ... point-slope form Simplify to slope-intercept form, $y=mx+b$ $y=\displaystyle \frac{1}{2}x -1 \qquad$ ... is the slope-intercept form For function notation, replace $y$ with $f(x)$.