Question

Which two points lie on a line with an undefined slope?

A. (-2,0) and (-2,5)
B. (-2,0) and (0,-2)
C. (0,0) and (2,2)
D. (3,0) and (2,0)

Answer 1

slope formula is
m = (y2 - y1)/(x2 - x1)

A. m = (5 - 0)/(-2 + 2)
m = (5)/(0)
m = error

B. m = (-2 - 0)/(0 + 2)
m = (-2)/(2)
m = -1

C. m = (2 - 0)/(2 - 0)
m = (2)/(2)
m = 1

D. m = (0 - 0)/(2 - 3)
m = (0)/(-1)
m = 0

the undefined slope would be the one that came out as error, so A

Answer 2

Option A.
`(-2,0)` and
`(-2,5)`

Explanation:

we know that

A vertical line has an undefined slope

The lines parallel to the y-axis are vertical lines

The points that lie on a vertical line has the same x-coordinate

In this problem

the points
`(-2,0)` and
`(-2,5)` has the same x-coordinate

therefore

The points lie on a line with an undefined slope (vertical line)