Question

How do you find the slope that is perpendicular to the line `y= -1`?

Answer 1

See a solution process below:

Explanation:

The line described by `y = -1` is a horizontal line where `y` is the same value for each and every value of `x`. Horizontal lines, by definition have a slope of `0`.

A perpendicular line therefore will be a vertical line.

Vertical lines, by definition, have an undefined slope.