17.5 Graphical Solution of Inequalities with Two Variables

  • Points Above and Below Curve • Use of Dashed Curve or Solid Curve • Solution Using Calculator

To this point, we have considered inequalities with one variable and certain methods of solving them. We may also graphically solve inequalities involving two variables, such as x and y. In this section, we consider the solution of such inequalities.

Let us consider the function y = f(x) .  We know that the coordinates of points on the graph satisfy the equation y = f(x) .  However, for points above the graph of the function, we have y > f(x) ,  and for points below the graph of the function, we have y < f(x) .  Consider the following example.

EXAMPLE 1 Checking points above and below line ...

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