Math
Graphing inequalities.
Definition
The process of representing inequalities on a number line or coordinate plane. On a number line, open circles show < or > and closed circles show ≤ or ≥. On a coordinate plane, dashed lines show strict inequalities and solid lines show inclusive ones, with shading on the solution side.
How it works · 4 phases
Step by step.
- Graph the boundary line or point (dashed for < or >, solid for ≤ or ≥).
- Choose a test point not on the boundary (often the origin).
- Substitute the test point into the inequality.
- If the test point satisfies the inequality, shade that side; otherwise shade the opposite side.
Examples
Real-world.
- 1 y > 2x + 1 is graphed with a dashed line and shading above
- 2 x ≤ 3 on a number line has a closed dot at 3 with shading to the left
- 3 y ≤ −x + 4 uses a solid line with shading below