What is the slope of a line that is perpendicular to a slope of #1/3#?

2 Answers
Serena D.
Mar 23, 2018

-3

Explanation:

Perpendicular slopes are opposite reciprocals of each other.

Opposites: positive vs negative

The perpendicular slope of a positive slope must be negative, and vice versa.

Reciprocals: multiplicative inverses (the numbers will multiply to 1)

Examples of reciprocals:

#2, 1/2 rarr# #2*1/2=1#

#1/3, 3 rarr# #1/3*3=1#

The opposite of #1/3# is #-1/3#, the reciprocal of #-1/3# is #-3#.

The Legend
Mar 23, 2018

#-3#

Explanation:

The slope of two perpendicular lines are negative reciprocals of each other. That means that you flip the fraction upside down and take the opposite of it. The reciprocal of #1/3# is #3#. The opposite of #3# is #-3#. So the slope is #-3#.

Related questions
See all questions in Equations of Perpendicular Lines
Impact of this question
15959 views around the world
You can reuse this answer
Creative Commons License