Functions and graphs > Inequalities
12345Inequalities

Theory

An expression such as f ( x ) > g ( x ) or f ( x ) < g ( x ) , etc., is called an inequality.
Inequalities can be solved using the corresponding graphs.

  • First enter both functions in your graphing calculator.

  • Adjust the settings so that both functions, especially all their intersects, are clearly visible.

  • Then you determine the coordinates of the intersects.
    You can use your calculator to do this, but often you can also find those points algebraically by solving the equation f ( x ) = g ( x ) . This can be quicker and more practical, or you may be explicitly asked to do so.

  • Finally, you can read off the solution to your inequality from the graphs.
    Make sure you apply the required precision!

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