A formula, describing the relation between the variables and , is called as a function of , when this formula appears as . The -values are the input values, the -values are the outcomes. In the corresponding graph the -values are always found on the vertical axis.
In the formula , ia a function of . When you substitute , the outcome is . Notation: .
In the formula , is a function of . When you substitute , the outcome is . Notation: .
Formulas such as can be entered into your graphic calculator.
Occasionally you need to re-write the formula to be able to enter it into your graphic calculator. When you re-write you should use the following rules:
you may add or subtract the same amount on both sides of the equal sign;
you may multiply or divide by the same amount on both sides of the equal sign (with the exception of multiplying or dividing by );
and occasionally you need to remove the brackets first.