Point-Slope Form What we Know so far…. Slope Intercept Form y m x b Where m is the slope and b is the intercept What we Know so far…. Slope rise y y2 y1 m run x x2 x1 Where two points are given as (x1,y1) and (x2,y2) The New Stuff… Write equations Slope-intercept form is: y m x b Where m is the slope and b is the y-intercept Example: Find the equation of the line with slope -2 and y-intercept 8 y = -2x + 8 Easy if I know the y-intercept… but if I don’t? The New Stuff… Point- Slope Form Point- Slope form is: y y1 m( x x1 ) Where m is the slope and (x1,y1) is the given point that the line goes through The New Stuff… Point- Slope Form Point- Slope form is: y y1 m( x x1 ) Where does this equation come from? y2 y1 m x2 x1 Using Point-Slope Form to graph 5 5 y 3 ( x 2) 4 2 3 2 y y m ( x x ) 1 1 1 -5 -4 -3 -2 -1 1 2 3 -1 -2 -3 -4 -5 4 5 Slope is 5 2 Point is (2,3) Manipulate Point-Slope Form to Slope-Intercept form 5 y 3 ( x 2) 2 5 y 3 x5 Simplify 2 5 y x2 2 Using Point-Slope Form to graph y 3 2( x 4) 5 4 3 2 1 -5 -4 -3 -2 -1 y y1 m( x x1 ) 1 2 3 -1 -2 -3 -4 -5 4 5 Slope is 2 1 Point is (4,-3) Manipulate Point-Slope Form to Slope-Intercept form y 3 2( x 4) y 3 2 x 8 y 2 x 5 Your turn 1 y 1 ( x 1) 3 5 y 2 ( x 3) 2 1 y 3 ( x 1) 4 Homework Pg. 304 #2 to 8 even Write slope and point Plot graph Write equation in slope intercept form