Chapter 17: Activities
315
Graphing the Unit Circle and Trigonometric Curves
Problem
Using parametric graphing mode, graph the unit circle and the sine curve to show the relationship
between them.
Any function that can be plotted in
Func
mode can be plotted in
Par
mode by defining the
X
component as
T
and the
Y
component as
F(T)
.
Procedure
1. Press
z
. Select
Par
,
Simul
, and the default settings.
2. Press
p
. Set the viewing window.
3. Press
o
. Turn off all functions and stat plots. Enter the expressions to define the unit circle
centered on (0,0).
4. Enter the expressions to define the sine curve.
5. Press
r
. As the graph is plotting, you may press
Í
to pause and
Í
again to
resume graphing as you watch the sine function “unwrap” from the unit circle.
Note:
•
You can generalize the unwrapping. Replace
sin(T)
in
Y2T
with any other trig function to
unwrap that function.
Tmin=0
Tmax=2
p
Tstep=.1
Xmin=
L
2
Xmax=7.4
Xscl=
pà
2
Ymin=
L
3
Ymax=3
Yscl=1