Write the equation of a line that is perpendicular to x=3 and that passes through the point (0, -4)

Answer 1

Here, the line is perpendicular to a line with slope m = infinity. So, the slope of the line that we need to find must be -1 / m = -1 / infinity = 0. This means the line we need to describe is flat, and is written as y = a, with "a" being the constant we have to find.

We are also told that it passes through the point y = -4. So there we go: the equation for the line is y = -4.