Objective- To find the slope of a line given Lesson 3.5 Slope of a Line 3:5 Slope of a Line Objective- To find the slope of a line given two points. y Graph y = 2x - 3 x y -3 -2 -1 1 2 3 -9 -7 -5 -3 -1 1 3 x y = 2x - 3 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series Algebra 1 by James Wenk © 2003 published by TEACHINGpoint
Objective- To find the slope of a line given two points. Slope of a line y vertical change Slope (m) = horizontal change +1 y Slope (m) = x +2 rise Slope (m) = run -2 x -4 +2 Slope (m) = = -4 y-intercept = -3 -2 +1 m = 2 y = 2x - 3 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y x Find the slope of the line below. Slope (m) = +1 Slope (m) = +3 +3 rise Slope (m) = run +1 Slope (m) = +3 x +3 1 m = 3 +1 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y x Find the slope of the line below. +2 Slope (m) = +3 Slope (m) = +3 rise +2 Slope (m) = run +3 Slope (m) = +3 +2 x 3 m = 2 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y x Find the slope of the line below. -1 -1 -1 Slope (m) = Slope (m) = rise Slope (m) = run -1 Slope (m) -1 = +4 x +4 -1 m = 4 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y x Find the slope of the line below. -4 -4 Slope (m) = Slope (m) = +2 rise Slope (m) = run -4 Slope (m) = +2 x -4 = -2 m +2 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y x Find the slope of the line below. Slope (m) = +5 +2 Slope (m) = +2 rise Slope (m) = run +5 +2 Slope (m) = +2 +5 x 2 m = 5 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y x Find the slope of the line below. -4 -4 Slope (m) = Slope (m) = +1 rise Slope (m) = run -4 Slope (m) = -4 +1 x = -4 m +1 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
y Algebraic Method to Find Slope Given Two Points Slope (m) = y rise Slope (m) = run y Slope (m) = 2 x (1,2) y2- y1 Slope (m) = x2- x1 2 - -3 Slope (m) = 1 - -2 5 Slope (m) = 1 3 (-2,-3) 5 m = 3 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
Algebraic Method to Find Slope Given Two Points 1 2 Find the slope between (-1,3) and (4,7). y2- y1 y Slope (m) = = x x2- x1 7 - 3 Slope (m) = 4 - -1 4 Slope (m) = 5 4 m = 5 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
-1 - 6 -7 -2 Algebraic Method to Find Slope Given Two Points Find the slope between (6,5) and (-1,7). y2- y1 m = x2- x1 7 - 5 m = -1 - 6 2 m = -7 -2 m = 7 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
-8 - 4 -12 -1 Algebraic Method to Find Slope Given Two Points Find the slope between (-8,7) and (4,1). y2- y1 m = x2- x1 7 - 1 m = -8 - 4 6 m = -12 -1 m = 2 Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
Slope of Horizontal and Vertical Lines Horizontal Lines Vertical lines x = -3 y = 2 m = 0 m = undefined y x = -3 y y = 2 x x Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
Slope of Horizontal and Vertical Lines Horizontal Lines Vertical lines (-2,2) (1,2) (-3,2) (-3, -1) y x = -3 y (-2,2) (1,2) (-3,2) y = 2 x x (-3,-1) Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series
-1 - 2 -3 - -3 -3 Slope of Horizontal and Vertical Lines Horizontal Lines Vertical lines (-2,2) (1,2) (-3,2) (-3, -1) 1 2 1 2 y2- y1 y2- y1 m = m = x2- x1 x2- x1 2 - 2 -1 - 2 m = m = 1 - -2 -3 - -3 -3 m = m = 3 Watch Out! m = undefined or there is “no slope” m = 0 m = 0 for all Horizontal Lines m = undefined for all Vertical Lines Algebra I by James Wenk © 2003 published by TEACHINGpoint as part of the Expert Systems for Teachers Series