Question 76694: Determine which two equations represent perpendicular lines.
(a) y=2/9x-3 (b) y=3x-2/9 (c) y=-1/3x+2/9 (d) y=1/3x-2/9 Answer by funmath(2933) (Show Source):
You can put this solution on YOUR website! Determine which two equations represent perpendicular lines.
(a) y=2/9x-3 (b) y=3x-2/9 (c) y=-1/3x+2/9 (d) y=1/3x-2/9
These lines are all in slope intercept form , m=slope and (0,b)=y-intercept. Perpendicular lines have slopes that are negative reciprocals of each other. They have opposite signs and are upside down from each other. Because of that if you multiply them you get -1.
The slopes are:
(a) m=2/9 (b) m=3 (c) m=-1/3 (d) m=1/3
There is only one negative slope (c) m=-1/3, so it has to be one of the lines.
(b) has a slope of m=3. 3=3/1 which is the negative reciprocal of -1/3. Therefore (b) and (c) are perpendicular lines.
Happy Calculating!!!
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