Question

What is the slope of the line that passes through the points (9, 4) and (9,- 5)?

Write your answer in simplest form.

Answer 1

• (9,4)
• (9,-5)

`\\ \sf\longmapsto m=(y_2-y_1)/(x_2-x_1)`

`\\ \sf\longmapsto m=(-5-4)/(9-9)`

`\\ \sf\longmapsto m=(-9)/(0)`

`\\ \sf\longmapsto m=\infty`

Answer 2

• Undefined

Explanation:

The given two points have same x- coordinates, hence the line vertical and is parallel to the y-axis:

• x = 9

Its slope is undefined.