# How do you find the slope perpendicular to x=-7?

##### 1 Answer
Nov 4, 2015

$0$

#### Explanation:

$x = - 7$ is a straight line parallel to the y-axis cutting the x-axis at -7. Its slope is undefined.

So a line perpendicular to this line will be a horizontal line parallel to the x-axis and cutting the y-axis at any point c.
Such a line will have zero gradient.