Solving Inequalities in 2 Variables

1. Solving Inequalities in 2 Variables Monday, February 10, 2014

2. What are the rules? • How do you graph a line? • You graph an inequality basically the same way… you need to isolate y. • If it can’t be equal, it’s like a regular inequality when you graph… the open circle becomes a dotted line. • If it can be equal, then like the closed circle, your line is solid.

3. Let’s try graphing and solving… • Graph and pick a point. Does the point satisfy the inequality? • Do a few more. Do you see a pattern? • Are the answers above or below the line? • When?

4. Where do you shade? • If it’s greater, shade above. • If it’s less than, shade below.

5. What if there is more than one inequality? • If there is more than one inequality, you have a system of inequalities. • Graph like you graph an inequality in 2 variables. • The solution for a system of inequalities is where the shading overlaps! • So, a system of inequalities has a range of solutions, not just one point. Sometimes a system has no solution.

6. Try it. • Using 2 different colored pencils, let’s see what happens. • Pick a color for each inequality. • Graph them on the same grid.

7. Homework Complete worksheet on Graphing Linear Inequalities and Solving Systems of Inequalities.

8. Mathalicious Lesson Datelines

9. Exit Ticket On a half-sheet of paper, list the rules for solving systems of inequalities.