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Unformatted text preview: 12 12 Slopes of lines Slope (m) Steepness of a line m = y2 y1 OR rise OR Δ y x2 x1 run Δx
Horizontal lines: m = 0 Vertical lines: m is undefined or no slope Positive slope: line goes uphill left to right Negative slope: line goes downhill left to right
Aug 2910:26 AM Y = mx + b slopeintercept form Find the slope(m) and yintercept(b) of the following lines.
Exs. 1. 7x + 13y = 26 2. 4x + 3y = 9 Aug 2910:33 AM 1 12 Parallel lines have equal slopes: m1 = m2
Perpendicular lines have opposite reciprocal slopes: m1 = 1/m2 Ex. a line l has equation x + 2y = 5 a) find the slope of a parallel line.
b) find the slope of a perpendicular line.
Aug 2910:35 AM Ex. Find the value of k if the line joining (2,k) and (4,5) and the line y = 3x + 1 are a) parallel
b) perpendicular Aug 2910:46 AM 2 12 H.W. pp. 1113 123 odd Aug 2910:48 AM 3 ...
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