Procedure for graphing a linear inequality
Step 1 Graph the
boundary
Replace the inequality symbol with an equality symbol
and draw the resulting line. This is the boundary
line. The boundary line is solid when the boundary
is included (less than or equal to; greater than or equal
to). The boundary line is dashed when the bound
is not included (less than; greater than).
Step 2 Test a point
Choose any point in the plane that is not on the boundary
line; the point (0, 0) is usually the simplest choice.
If this test point makes the inequality true,
shade the half-plane which contains the test point.
That is, the shaded (highlighted) plane is the solution
set. If the test point makes the inequality
false, shade the other half-plane for the solution.
