User's Manual

9-2 Split Screen
8309SPLT.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:31 PM Printed: 02/19/01 1:36
PM Page 2 of 6
Getting Started is a fast-paced introduction. Read the chapter for details.
Use
G
.
T (graph-table) split-screen mode to explore the unit circle and its
relationship to the numeric values for the commonly used trigonometric angles
of 0
°
, 30
°
, 45
°
, 60
°
, 90
°
, and so on.
1. Press
z
to display the mode screen.
Press
† † ~ Í
to select
Degree
mode. Press
† ~ Í
to select Par
(parametric) graphing mode.
Press
† † † † ~ ~ Í
to select
G
.
T
(graph-table) split-screen mode.
2. Press
y
[
FORMAT
] to display the format
screen. Press
† † † † † ~ Í
to
select
ExprOff.
3. Press
o
to display the
Y=
editor for Par
graphing mode. Press
™ „ ¤
Í
to store
cos(T) to X
1T
. Press
˜
„ ¤ Í
to store
sin(T) to Y
1T
.
4. Press
p
to display the window
editor. Enter these values for the window
variables.
Tmin=0 Xmin=
L
2.3 Ymin=
L
2.5
Tmax=360 Xmax=2.3 Ymax=2.5
Tstep=15 Xscl=1 Yscl=1
5. Press
r
. On the left, the unit circle is
graphed parametrically in
Degree mode
and the trace cursor is activated. When
T=0 (from the graph trace coordinates),
you can see from the table on the right
that the value of
X
1T
(cos(T)) is 1 and Y
1T
(sin(T)) is 0. Press
~
to move the cursor to
the next 15
°
angle increment. As you trace
around the circle in steps of 15
°
, an
approximation of the standard value for
each angle is highlighted in the table.
Getting Started: Exploring the Unit Circle