Calculator User Manual

Chapter 17: Activities 508
Now graph the equation to see visually how the area changes as the number of sides
gets large.
8. Press z. Select the default mode settings.
9. Press p. Set the viewing window.
10. Press o. Turn off all functions and stat plots. Enter the equation for the area. Use
X
in place of
N. Set the graph styles as shown.
11. Press r. After the graph is plotted, press
100 Í to trace to X=100. Press 150
Í. Press
188 Í. Notice that as X increases, the value of Y converges to p6
2
,
which is approximately 113.097.
Y2=pB
2
(the area of the circle) is a horizontal
Xmin=0
Xmax=200
Xscl=10
Ymin=0
Ymax=150
Yscl=10
Xres=1