How to Graph Inequalities on the TI-84 Plus

As with functions, if the inequality sign in the definition of the inequality is highlighted in Inequality Graphing on the TI-84 Plus, then that inequality will be graphed; if it isn’t highlighted, it won’t be graphed. The first image shows that the first two inequalities will be graphed, but the third won’t. To change the highlighted status of an inequality sign, place the cursor on that sign and press [ENTER].

You graph the inequalities defined in the Y= and X= editors the same way you graph a normal function. You either define the variables in the Window editor and press [GRAPH] or use one of the Zoom commands. When the graph is displayed, you see three options at the bottom of the graph screen, as in the third image.

The Inequality Graphing application adds the ShadeRes variable to the Window editor. This variable can be set to any integer 3 through 8. A setting of 3 places the lines in the shaded graph close together and 8 places then far apart. The default value is 3, and this setting works just fine for most graphs.