Question

What is the slope of the line that passes through (1, 4) and (1, −3)?

7,
-7,
0,
undefined

Answer 1

The formula of a slope:

`m=(y_2-y_1)/(x_2-x_1)`

We have the points (1, 4) and (1, -3). Substitute:

`m=(-3-4)/(1-1)=(-7)/(0)\qquad\boxed{!!!!}`

DIVISION BY ZERO!!!

Answer: The slope is undefined.

It's a vertical line x = 1.