HP 39gs Graphing Shading area, Intersection, Cursor. You need to have at, Symbolic view. Displays

Shading area

Function	Description (Continued)
Intersection	Select Intersection to find the
	intersection of two graphs nearest
	the cursor. (You need to have at
	least two selected expressions in
	Symbolic view.) Displays the
	coordinate values and moves the
	cursor to the intersection. (Uses
	Solve function.) The resulting x-
	value is saved in a variable
	named ISECT.

You can shade a selected area between functions. This process also gives you an approximate measurement of the area shaded.

1.Open the Function aplet. The Function aplet opens in the Symbolic view.

2.Select the expressions whose curves you want to study.

3.Press to plot the functions.

4.Press or to position the cursor at the starting point of the area you want to shade.

5.Press .

6.Press , then select Signed area and press

.

7.Press , choose the function that will act as the boundary of the shaded area, and press .

8.Press the or key to shade in the area.

9.Press to calculate the area. The area measurement is displayed near the bottom of the screen.

To remove the shading, press to re-draw the plot.

Function aplet 3-11