Question

Find the equation of a vertical line that passes through the point (2,3)

Answer 1

First: what is the slope, if any, of a vertical line?

Answer 2

It does not have a slope, right?

Answer 3

If a vertical line passes through (2,3), what is the x-coordinate there?

"It does not have a slope, right?" Or, equivalently, the slope of a vert. line is undefined (due to division by zero).

Answer 4

would it be y = 3

Answer 5

if the change in x is 0, then the line is vertical because there is no change in the x values of the line, only in the y values. That means it can only pass through one x value. In this case, the answer is the x value of the coordinate.