If line #q# has a slope of -2, what is the slope of any line perpendicular to #q#?

2 Answers
Feb 13, 2018

The slope of any line perpendicular to #q# will be #1/2#.

Explanation:

The slopes of perpendicular lines will be opposite reciprocals of each other.

In the phrase "opposite reciprocals," the word "opposite" means negative, and "reciprocal" means a flipped fraction. To achieve the opposite reciprocal of a number, simply flip it, then multiply by #-1#.

For example, the opposite reciprocal of #1/3#:

#1/3=>3/1*-1=3*-1=-3#

If the number doesn't happen to be a fraction and you can't flip it, simply add a #1# under it to represent division by #1# (which doesn't change the number). For instance, the opposite reciprocal of #2#:

#2=2/1=>1/2*-1=-1/2#

In this problem, we want the opposite reciprocal of #-2#, which is:

#-2=(-2)/1=>1/(-2)*-1=(-1)/(-2)=1/2#

That means the slope of any line perpendicular to line #q# will have a slope of #1/2#.

Feb 13, 2018

#1/2#

Explanation:

#"given a line with slope m then the slope of any line"#
#"perpendicular to it is"#

#•color(white)(x)m_(color(red)"perpendicular")=-1/m#

#"here "m=-2#

#rArrm_(color(red)"perpendicular")=-1/(-2)=1/2#