 # Parallel & Perpendicular Lines Parallel Lines m = 2/1 What is the slope of the 2 nd line? +1 +2 +1 +2.

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Parallel & Perpendicular Lines

Parallel Lines m = 2/1 What is the slope of the 2 nd line? +1 +2 +1 +2

Perpendicular Lines m = 2/1 What is the slope of the 2 nd line? +1 +2 m = -1/2

Parallel : Same Slope Perpendicular : Opposite Reciprocal Slope m = 2/1 m = -1/2

Perpendicular : Opposite Reciprocal Slope m = -2/1m = +1/2 m = +1/3m = -3/1

Find the equation for the line parallel to 2x + y = 6 and passing through ( 2, -3 ) First, we need slope and a point: 2x + y = 6 y = -2x + 6 m = -2Point: ( 2, -3 )

With… slope -2 and point (2,-3) y = -2x + b -3 = -2(2) + b y = -2x + 1

Find the equation for the line perpendicular to x + 3y = 6 and passing through ( 1, -2 ) First, we need slope and a point: x + 3y = 6 3y = -1x + 6 m = -1/3 Point: ( 1, -2 ) y = -1/3(x) + 2 But perpendicular, so +3/1

With… slope 3 and point (1,-2) y = 3x +b -2 = 3(1) + b y = 3x - 5

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