## College Algebra 7th Edition

$x=2$
RECALL: (1) A vertical line has an undefined slope and has an equation of the form $x=h$ where $h$ is the x-coordinate of all the points on the line. (2) A horizontal line has a slope of zero and has an equation of the form $y=k$ where $k$ is the y-coordinate of all the points on the line. (3) A vertical line and a horizontal line are perpendicular to each other. The line we are looking for the equation if is perpendicular to the line $y=1$. $y=1$ is a horizontal line so its slope is zero. This means that the line we are looking for the equation of is vertical and has an equation of the form $x=h$. The line passes through the point $(2, 6)$. The x-coordinate of this point is $2$. Therefore, the equation of the line we are looking for is: $x=2$