1. Ch 6.8 Objective: To graph inequalities on the coordinate plane.

2. Graph n < 3 on a number line. - 3 - 2 - 1 0 1 2 3 4 Review

3. More Review Graph n ≥3 on a number line. - 3 - 2 - 1 0 1 2 3 4

4. Steps for Graphing Linear Inequalities 1.For the purposes of creating the line, change the inequality sign to an equal sign. 2.Draw the line using any method you learned in Chapter 4 (x,y chart, intercept then slope, x,y intercepts, etc.) 3.Determine if the line is solid (≥, ≤) or dashed (>, <) and graph it. 4.Choose a point NOT on the line and plug into inequality. If TRUE then shade that side If FALSE then do NOT shade that side (shade the OTHER SIDE)

5. Graph y - 3x + 2 on the coordinate plane. x y Boundary Line y = -3x + 2 m = -3 b = 2 Test a point not on the line test (0,0) 0 -3(0) + 2 Not true! Example 1

6. Graph y - 3x + 2 on the coordinate plane. x y Instead of testing a point If in y = mx + b form... Shade up Shade down Solid line Dashed line >< Example 1 (again)

7. Graph y > 3 on the coordinate plane. x y Example 3

8. Graph x - 2 on the coordinate plane. x y Example 4

9. Graph on the coordinate plane. 3x - 4y > 12 - 3x - 4y > - 3x + 12 - 4 y < x - 3 m = b = - 3 Boundary Line x y Example 5

10. Problem If you have less than $5.00 in nickels and dimes, find an inequality and sketch a graph to describe how many of each coin you have. Let n = # of nickels Let d = # of dimes 0.05 n + 0.10 d < 5.00 or 5 n + 10 d < 500

11. nd 0 50 1000 0 10 20 30 40 50 60 70 80 90 100 n d 60 50 40 30 20 10 0