Algebra-1

To determine if a line has an undefined slope between two points  and , we use the slope formula . A line has an undefined slope when the denominator  is equal to , which means the -coordinates of the two points are the same.

Let's analyze each pair of points:

A:  and

For these points, , , , and .

The slope .

B:  and

Here, , , , and .

The slope

Click "Show Answer" to reveal the answer and analysis