# Graphing quadratic inequalities in two variables

### Graphing quadratic inequalities in two variables

Grab a pen and grid paper for this lesson. We will learn the tricks on graphing quadratic inequalities in two variables.

#### Lessons

• 1.
Graphing Quadratic Inequalities of Parabolas Opening Up
Graph:
i) $y = \frac{1}{3}{x^2} - \frac{2}{3}x - \frac{8}{3}$
ii) $y \ge \frac{1}{3}{x^2} - \frac{2}{3}x - \frac{8}{3}$
iii) $y$ < $\frac{1}{3}{x^2} - \frac{2}{3}x - \frac{8}{3}$

• 2.
Graphing Quadratic Inequalities of Parabolas Opening Down
Graph:
i) $y = - {x^2} - 4x$
ii) $y$ > $- {x^2} - 4x$
iii) $y \le - {x^2} - 4x$