What is the slope of any line perpendicular to the line passing through #(-2,7)# and #(-2,3)#?

1 Answer
Nov 9, 2017

Answer:

#y=0# graph{y=0x [-9.83, 10.17, -4.96, 5.04]}

Explanation:

I'll be using slope-intercept form, #y=mx+b#, for this.

A perpendicular line is a line with a slope that is both the inverse and the reciprocal of the original slope. For example, #y=2/3# is perpendicular to #y=(-3/2)#. It does not matter what the y-intercept #b# is in this situation, the slope is what's important.

To find the slope, use the rise-over-run formula of #(y_2-y_1)/(x_2-x_1)#

#(3-7)/((-2)-(-2)) rArr (-4)/(0)#

This will be a special case. Since dividing by 0 is undefined, this makes your slope undefined. Contrary to the rules explained above, which should work for all other questions, your slope in this case is a perfectly horizontal line, as undefined is perfectly vertical.

A horizontal line is called a slope of zero. As you'll see, the name is quite fitting, because your answer is:

#y=0#