How do you find the line perpendicular to $y=6$ passing through $(-1,6)$?

Question

A line has the equation $y = 6$. Find the perpendicular line that passes through $(-1,6)$.

$m1 = -1/m2$

$m1 = -1/0$

$m1$ = Math error

Isn't that how you find the second slope? I got math error on this one.

Answer 1

$ y = 6 $ is a horizontal line, so a perpendicular line to it, is a vertical line, and vertical lines have the equation, $ x= a$. Since the required line passes through $(-1, 6)$, then $a = -1$, hence the equation of the required line is

$$ x = -1 $$