Question

Find the equation of the line that contains the point (2,8), and has a slope that is undefined.

Answer 1

By slope that is undefined, I'm assuming you mean the line is a vertical line (constant x coordinate)

Answer 2

Since you have a constant x coordinate and can freely vary the y coordinate, consider the set of points that would then be on the line if you had to include (2,8).

Answer 3

Clearly 2, the x coordinate, is the unchanging x value, while y can be anything.

Answer 4

Normally you give equations for lines in terms of y = ax + b (or y = mx + b or whatever), but here we cannot give any y = anything because y can vary freely and cannot be solved for.

Answer 5

So all we can say is x=2.

Answer 6

The set of points (x1,y1) that solve that equation represent the points on the vertical line through the point (2,8).

Answer 7

I hope that helps