## 15.2 Outline

- half-plane
- boundary
- open/closed

- Procedure for graphing a linear inequality

## 15.2 Essential Idea

Procedure for graphing a linear inequality

*Step 1
*

**Graph the boundary.**Replace the inequality symbol with an equality symbol and draw the resulting line. This is the

*boundary line*. The boundary line is solid when the boundary is included (less than or equal to; greater than or equal to). The boundary line is dashed when the bound is not included (less than; greater than).

*Step 2
*

**Test a point.**Choose any point in the plane that is not on the boundary line; the point (0, 0) is usually the simplest choice. If this

**test point**makes the

*inequality*true, shade the half-plane which contains the test point. That is, the shaded (highlighted) plane is the solution set. If the test point makes the

*inequality*false, shade the other half- plane for the solution.