How to Shade Graph Unions and Intersections
When a graph is displayed in Inequality Graphing on the TI-84 Plus calculator, Shades is one of three options that appear at the bottom of the screen. The Shades option redraws the graph shading only the union or intersection of the regions.
Most graphs of more than two inequalities can get pretty cluttered. The Shades option will get rid of the clutter by shading only the union or the intersection of the regions. To accomplish this, follow these steps:
Press [ALPHA][Y=] or [ALPHA][WINDOW] to display the Shades menu.
Because the Shades option at the bottom of the graph screen is above the F1 and F2 function keys on the calculator, pressing either [ALPHA][Y=] to select F1 or [ALPHA][WINDOW] to select F2 will produce the Shades menu.
Press the number of the option you want.
The new graph automatically appears on the screen.
After graphing the union or intersection of the regions in your graph, you can redisplay the original shading of the graph by selecting the third option in the Shades menu.