## Precalculus (6th Edition)

(a) Standard form $y=-4$ (b) Slope-intercept form $y=-4$
RECALL: (1) The standard form of a line's equation is $Ax+By=C$. (2) 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. (3) Vertical lines and horizontal lines are perpendicular to each other. (4) Horizontal lines have points that share the same y-coordinate. The line is perpendicular to the vertical line $x=-2$. This means the line we are looking for is a horizontal line. Since the the horizontal line contains the point $(4, -4)$, and a horizontal line's points share the same y-coordinate, then the equation of the line must we are looking for is $y=-4$. (a) Standard form $y=-4$ (b) Slope-intercept form $y=-4$