Solving Quadratic Inequalities with a Sign Graph

We summarize the strategy for solving a quadratic inequality as follows.

Strategy for Solving a Quadratic Inequality with a Sign Graph

1. Write the inequality with 0 on the right.

2. Factor the quadratic polynomial on the left.

3. Make a sign graph showing where each factor is positive, negative, or zero.

4. Use the rules for multiplying signed numbers to determine which regions satisfy the original inequality.