When you select Cartesian from the Function Type dialog, the next line contains a general form of the function in terms of Y.
You can define this function in these ways:
| • | Modify the formula directly: |
| • | Modify the function interactively using "handles". In the drawing window, click the function to select it. Click and drag it and a circle appears on the curve. This handle represents one of the variables in the equation. You can click and drag this handle around the drawing. Click and drag another place on the function and another moveable handle appears if there is another variable in the equation. |
This feature is a wonderful way to understand exactly how the equation represents the function.
In the first example, 
, a click gives you the b handle, the y-intercept, and lets you drag the function up and down. Click and drag another place on the curve and you get the a handle to change the shape of the curve.
Notice the Variable toolbox displays the changing values as you move the handles.
| • | Modify the function after it's drawn by double clicking the function tag. |