1. Quadratic Inequalities
Section 3.6

2. Bellwork

3. What You Will Learn Graph quadratic inequalities in two variables.
Solve quadratic inequalities in one variable.
Graphing Quadratic Inequalities in Two Variables

4. A quadratic inequality in two variables can be written in one of the following forms, where a, b, and c are real numbers and a ≠ 0.

5. Take Note

6. Graphing a Quadratic Inequality in Two Variables Graph y < −x2 − 2x − 1.

7. Graphing a System of Quadratic Inequalities

8. Practice

9. Solving Quadratic Inequalities in One Variable
A quadratic inequality in one variable can be written in one of the following forms, where a, b, and c are real numbers and a ≠ 0.
ax2 + bx + c < 0
ax2 + bx + c > 0
ax2 + bx + c ≤ 0
ax2 + bx + c ≥ 0
You can solve quadratic inequalities using algebraic methods or graphs.