Section 3-3: Graphing Inequalities Pages in textbooks

Objectives I can determine solid or dashed boundary lines and what they mean I can solve systems of inequalities by graphing them. I can identify if a solution works or not in an inequality.

System of Inequalities When you have 2 or more inequalities to solve at one time, we call this a system of inequalities. The solution to the system is the common shaded region of the graph

Inequalities Key Concept –When re-arranging an inequality if you DIVIDE by a Negative number, then you FLIP the direction of the inequality

Graphing Inequalities 2 Main Rules 1. Graph the Boundary (solid or dashed) 2. Shade the correct side (Above or Below)

Boundary Lines 2 Types of Boundary Lines Solid Lines –Used when you have inequalities ≤ or ≥ –Any point on a solid boundary is in the solution –Similar to Closed Circle on a number line Dashed Lines –Used when you have inequalities –Any point on a dashed boundary is not in the solution –Similar to an Open Circle on a number line

Shading If symbols < or ≤ Shade below the boundary line If symbols > or ≥ Shade above boundary line

Graph the following system of inequalities

Using the Calculator The calculator will also work to show correct shading. Instead of y =, you will have to change the symbol on the left side of the equation to either It will not show dashed versus solid boundaries.

Another Example y  2x – 3 y < 2 x > -2

Homework WS 7-2 Factoring Quiz Tomorrow