Click the Function list button in the Graph Options dialog - Custom Function (2D Graphs) or Custom Function (3D XYZ Graphs) options panes to display the Function Name Manager. Use this dialog to manage 2D and 3D custom functions. For example, when this dialog is displayed from the (2D) Custom Function options pane of the Graph Options dialog, then you can select a previously specified 2D function from the list.
Functions. The Functions list displays a list of currently defined functions.
Select. Click the Select button to select the currently highlighted function (in the list of functions), and close the dialog. The content of that function will automatically be transferred to the respective edit field (for a custom function) on the dialog or dialog tab from which the Function Name Manager was called.
Cancel. Click the Cancel button to close this dialog, ignoring any changes you have made.
Edit. To edit a currently defined function, highlight the function in the Functions box, then click the Edit button. The Edit Custom Function dialog will be displayed, where you can modify the function. To change the name of the function, use the Rename button.
New. Click the New button to create a new function. After specifying a name for the new function in the Custom Function dialog, you will be able to define the function in the Edit Custom Function dialog. The new function will be added to the Functions list.
Delete. Click the Delete button to delete the currently selected function.
Rename. Click the Rename button to rename the currently selected function. The Custom Function dialog will be displayed in which you can specify a new name for the functions.