Question

What is the equation of a vertical line passing through the point (−5, −1)?

Answer 1

`color(blue)(x=-5)`

Explanation:

The equation of a vertical line is:

`x=a`

Where `a` is some real number on the x axis.

Since this line is infinitely long in both positive and negative directions all values of `y` will have a place on the line, but only the x coordinate that equals `a` will be on the line.

We could write all coordinates on the line as `(a, y)`

Our example gives `x=-5` and this is the equation of the vertical line.

The coordinates of every point on the line would be:

`(-5,y)` for any `y`