Question 66590: Determine which two equations represent perpendicular lines. (a) y=5x-5 (b) y=1/5x+5 (c) y=-1/5x+5 (d) y=1/5x-5. Answer by funmath(2933) (Show Source):
You can put this solution on YOUR website! Determine which two equations represent perpendicular lines.
(a) y=5x-5 (b) y=1/5x+5 (c) y=-1/5x+5 (d) y=1/5x-5
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(a) and (c) are perpendicular, this is how you can tell:
These lines are all in slope intercept form, , where m=slope and b=y-intercept.
Perpendicular lines have slopes that are negative reciprocals of each other, that means their slopes have opposite signs and are upside-down. Because of that if you multiply their slopes you get -1
The slope of (a) is m=5, the slope of (c) is m=-1/5. They are negative reciprocals of each other,
Happy Calculating!!!
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