Slope Intercept Form Graphing the easy way 2/19/2019 13-5

Why use slope-intercept? Speed Simplicity It’s on the test. 2/19/2019 13-5

What to do… Gives the slope and y-intercept y = mx + b Slope intercept form: y-intercept The slope Graph Where the graph intercepts the y-axis (b) m m is the slope b is the y-intercept 2/19/2019 13-5

For Example y = 2x + 1 In the form y = mx + b m = 2 and b = 1 slope = 2 y-int = 1 2/19/2019 13-5

For the following, name the slope and y-intercept. 1.) y = 3x + 4 2.) y = x + 2 3.) y = 7x – 3 m = 3 b = 4 m = 1 b = 2 m = 7 b = -3 4.) y = ½ x – 8 5.) y = -3x 6.) y = 6x + 9 m = ½ b = -8 m = -3 b = 0 m = 6 b = 9 2/19/2019 13-5

To Graph…y = 2x + 1 (just watch this one) We know the y-int = 1 and slope = 2 (2/1) First: y-intercept Second: slope Third: Draw line run run (1) rise rise (2) 2/19/2019 13-5

7.) Try this one… y = x + 2 y-int = 2 and slope = 1 (1/1) First: y-intercept Second: slope Third: Draw line run run rise rise 2/19/2019 13-5

8.) Try this one… y = ½ x + -2 y-int = -2 and slope = ½ First: y-intercept Second: slope Third: Draw line run run rise rise 2/19/2019 13-5

9.) Try this one One more… y = -2x + 3 y-int = 3 and slope = -2 (-2/1) First: y-intercept Second: slope Draw line rise run rise run 2/19/2019 13-5

Examples 10-12 Solve these problems and compare with a partner. 11 and 12 need to be solved for y first, so that they are in slope-intercept form. 2/19/2019 13-5

Conclusion When graphing an equation that is in slope intercept form: Graph y-intercept Follow rise and run of the slope Draw the line 2/19/2019 13-5