One characteristic of the line is that all points on the line have exactly the same coordinate, namely . So when you try to calculate the slope using the slope formula:
where and are the coordinates of the given points.
you end up with zero in the denominator regardless of what points you choose for the calculation. The value of a rational expression with a zero denominator is undefined. So the slope is ...
John
My calculator said it, I believe it, that settles it
