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Example Question #21 : Perpendicular Lines
Give the slope of the line perpendicular to .
To find the slope of a perpendicular line, we take the reciprocal of the known slope
, where
.
The easy way to do this is to simply take the fraction (a whole slope can be made into a fraction by placing in the denominator), exchange the numerator and denominator, then multiply the fraction by
Thus,
.
Example Question #21 : Perpendicular Lines
Calculate the slope of a line perpendicular to the line with the following equation:
None of these
Perpendicular lines will have slopes that are negative reciprocals of one another. Our first step will be to find the slope of the given line by putting the equation into slope-intercept form.
The slope of this line is .
First let's find the negative of the current slope.
Now, we need to find the reciprocal of . In order to find the reciprocal of a number we divide one by that number; therefore, we can calculate the following:
The negative reciprocal will be or
which will be the slope of the perpendicular line.
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