00calc5


 * Classpad 330 Calculator **toc

It is useful to define a function in a number of circumstances. The main use is if you will be using the same expression repeatedly as it saves you typing it in several times. {of course, you can always highlight and drag or cut and paste}

How to Define a Function
Go to the Main Screen
 * Either by clicking on Main in the main menu
 * Or by clicking on Main in the green icon bar

You will find the __**define**__ command in the ACTION menu, COMMAND submenu

Enter:
 * define** f(//**x**//) = //**x**// 2 + 2//**x**// {or whatever function you wish}

Use f from the ABC tab but use the variable (boldface) //**x**//.

You should see the word done. This means that the function f(//**x**//) is now defined.

Using a Defined Function
You can now use the function in a variety of ways:

f(3) gives the result of substituting //**x**// = 3 into the function.

3f(//**x**//) gives the result of multiplying the function by 3


 * solve**( f(//**x**//) = 8 ) gives the solution to the equation.

You can graph //**y**// = f(//**x**//)

etc

Make sure that you keep using f from the ABC tab but use //**x**// from the variable list.

Compound Functions
Having defined a function like f, we can use it to investigate compound functions: the result of using one function as the input to another function.

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