Defining and entering functions
1. From the Home Screen select the Function Editor icon or press c to display the Y= editor.
2. Press the down arrow ≥ to move the cursor to the function you want to define or edit.
3. Press q to erase a function.
4. Enter or edit the expression to define the function.
- You may use functions and variables (including matrices and lists) in the expression. When the expression evaluates to a nonreal number, the value is not plotted; no error is returned.
- You can access the shortcut menus by pressing b Ü - Ž.
- In function mode the independent variable in the function is X. Func mode defines l as X. To enter X, press l or press b X.
- When you enter the first character, the = is highlighted, indicating that the function is active.
- As you enter the expression, it is stored to the variable Yn as a user-defined function in the Y= editor.
5. Press = or the down arrow ≥ to move the cursor to the next function.
Setting up the viewing window for a graph
When a function is entered in the Y= editor, you can view a table of values by pressing a Ä.
Note: The table setup, a Ä, determines how table values are displayed. Check the table setup values if the table results are not in expected format of fraction. Using a mix of decimal and fractions will not retain fractions.
Setting up the formatting options for the graph space
Press a  to access all the graph formatting options. This menu includes the options for points of interest trace, grid and background color.
Using the zoom features
Press f key to access the quick zoom options. Quick zoom options include the ZDecimal (default window), ZStandard, ZoomFit and ZoomStat options.
Viewing and using the table
When a function is entered in the Y= editor, you can view a table of values by pressing a Ä.
Note: The table setup, a Á, determines how table values are displayed. Check the table setup values if the table results are not in expected fraction format. Using a mix of decimal and fractions will not retain fractions.