Operation Manual

Chapter 17: Activities 310
5. Press Í to zoom in. Move the cursor over the intersection.
6. Press Í to zoom in again. Move the free-moving cursor onto a point exactly on the intersection.
Notice the number of decimal places.
7. Press y /
5 to select 5:intersect. Press Í to select the first curve and Í to select the
second curve. To guess, move the trace cursor near the intersection. Press Í. What are the
coordinates of the intersection point?
8. Press q
4 to select 4:ZDecimal to redisplay the original graph.
9. Press q. Select 2:Zoom In and repeat steps 4 through 8 to explore the apparent function
intersection on the left side of the display.
Using a Program to Create the Sierpinski Triangle
Setting up the Program
This program creates a drawing of a famous fractal, the Sierpinski Triangle, and stores the drawing to a
picture. To begin, press  ~ ~ 1. Name the program SIERPINS, and then press Í. The program
editor is displayed.
Program
PROGRAM:SIERPINS
:FnOff :ClrDraw
:PlotsOff
:AxesOff:GridOff
:Full
:BackgroundOff
:0
!Xmin:1!Xmax
:0
!Ymin:1!Ymax
Set viewing window.
:rand!X:rand!Y
:For(K,1,3000)
:rand
!N
Beginning of For group.
:If N1à3
:Then
:.5X
!X
:.5Y
!Y
:End
If/Then group
:If 1à3<N and N2 à3
:Then
:.5(.5+X)
!X
:.5(1+Y)
!Y
:End
If/Then group.
:If 2à3<N
:Then
:.5(1+X)
!X
:.5Y
!Y
:End
If/Then group.
:Pt-On(X,Y,BLUE)
:End
:StorePic 6
Draw point.
End of
For group.
Store picture.