Graphing Inequalities in Two Variables
The inequality written in two variables is similar to an equation written in two variables. An easy way to show the solution of an inequality is to graph it in the coordinate plane.
The solution set of an inequality in two variables contains many ordered pairs. The graph of these ordered pairs fills an area on the coordinate plane called a half-plane. The graph of an equation defines the boundary or edge for each half-plane.
Step 1 Determine the boundary by graphing the related equation.
Step 2 Draw a dashed line since the boundary is not part of the graph.
Step 3 Determine which half-plane is the solution. To do this, substitute a point from each half-plane into the inequality. Find which point results in a true statement.
Find out more about graphing inequalities in two variables below.
Graphing Inequalities in Two Variables
Practice: Answer the following exercises by graphing inequalities on the coordinate plane.