without graphing, determine whether the following two points would be on a vertical line or a horizontal line.

(3, 4), (3, 8)
vertical
horizontal

Question

without graphing, determine whether the following two points would be on a vertical line or a horizontal line.

(3, 4), (3, 8)  
vertical
horizontal

aroub · Answer

8-4/3-3
4/0 

The slope is undefined so it's vertical.

mathmate · Answer

Since the x values are identical, the two points have the same x-values, and different y-values.  This implies they lie on a vertical line.

anonymous · Answer

(5, 1), (9, 1)

mathmate · Answer

The y-values are identical, so they lie on a horizontal line.

anonymous · Answer

Use the slope formula:  

$$m= (y _{2}-y_{1})/(x_{2}-x_{1})$$

y = (8-4)/(3-3) = 5/0  which is undefined so the line is vertical.

Lines with slope m = 0 are horizontal.