Question

The equation of any line perpendicular to the line y = 15.5 is of the form x = a. If a line is perpendicular to y = 15.5 and passes through the point (17.8, 15.5), what is the value of a?

Answer 1

x=17.8

Explanation:

Perpendicular lines intersect at 90 degrees or perpendicular angles. As such, their slopes are related. The slope of each line is the negative reciprocal of the other. For the equation, y=15.5 there is no slope and is a horizontal line through the y-axis. Therefore the perpendicular line is a vertical line through the x-axis and has form x=a. We write for a the x-coordinate of the point to form the line. x=17.8