## Calculus with Applications (10th Edition)

$x=-8$ This line has no slope-intercept form equivalent.
RECALL: (i) The slope-intercept form of a line's equation is $y=mx+b$ where $m$ = slope and $b$ = y-intercept. (ii) The formula for slope is $m=\dfrac{y_2-y_1}{x_2-x_1}$. Solve for the slope using the formula above to have: $m=\dfrac{6-4}{-8-(-8)}=\dfrac{2}{0}$ slope is undefined A line with an undefined slope is vertical and has an equation of the form $x=k$ where $k$ is the x-coordinate of all the points on the line. The point $(-8, 4)$ has a $x=-8$. Thus, the equation of the line is $x=-8$. This equation has no slope-intercept form equivalent.