Suppose we have two lines which are perpendicular. If the slope of one line is 5 and the slope of the other line is m then 5m = _______________.

A. -1
B. 0
C. 1
D. 1/2

Question

Suppose we have two lines which are perpendicular. If the slope of one line is 5 and the slope of the other line is m then 5m = _______________.


 		A.	-1
 		B.	0
 		C.	1
 		D.	1/2

mertsj · Answer

The slopes of perpendicular lines are negative reciprocals on each other.

mertsj · Answer

So if the slope of the given line is 5, then the slope of the perpendicular is -1/5 and that is the value of m.
I leave it to you to find 5m

kc_kennylau · Answer

That means the product of the slopes of two lines that are perpendicular to each other will always be -1

anonymous · Answer

do i divide it?

anonymous · Answer

but why is that? D: @kc_kennylau

kc_kennylau · Answer

The easiest explanation I can give involves trigonometry

kc_kennylau · Answer

I don't know if simpler explanations exist

anonymous · Answer

ahh okay v.v thankyou though! @kc_kennylau @Mertsj

mertsj · Answer

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