Inequalities in two variables can be graphed
on a graphing calculator using the "Shade(" command,
which is option 7 on the DRAW menu. You must enter two
functions to activate the shading since the calculator always
shades between two specified functions. The first function entered
defines the lower boundary of the region to be shaded. The second
function defins the upper boundary of the region. The calculator
graphs both functions and shades between the two.

Example 1:
Graph y2x - 3 in the standard
viewing window.

The inequality refers to points at which
y is greater than or equal to 2x - 3. This means we want
to shade above the graph of y = 2x - 3. Since the calculator
screen shows only part of the coordinate plane, we can use the
top of the screen, Ymax or 10, as the uppper boundary and 2x
- 3 as the lower boundary.

ENTER:7 2 - 3 , 10 )

Since both the x- and y-intercepts of
the graph and the origin are within the current viewing window,
the graph of the inequality is complete.

Example 2:
Graph y - x1 in the standard
viewing window.

First solve the inequality for y: yx + 1. This inequality refers
to points where y is less than or equal to x + 1. This
means we want to shade below the graph of y = x + 1. We can use
the bottom of the screen, Ymin or -10, as the lower boundary
and x + 1 as the upper boundary.