Getting Started: Exploring The Unit Circle - Texas Instruments TI-83 Manual Book

Getting Started: Exploring the Unit Circle

Getting Started is a fast-paced introduction. Read the chapter for details.
Use (graph-table) split-screen mode to explore the unit circle and its
G.T
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
mode. Press † ~ Í to select
(parametric) graphing mode.
Press † † † † ~ ~ Í to select
(graph-table) split-screen mode.
2. Press y [
FORMAT
screen. Press † † † † † ~ Í to
select .
ExprOff
3. Press o to display the
graphing mode. Press ™ „ ¤
Í to store
„ ¤ Í to store
4. Press p to display the window
editor. Enter these values for the window
variables.
Tmin=0 Xmin=L2.3
Tmax=360 Xmax=2.3
Tstep=15 Xscl=1
5. Press r. On the left, the unit circle is
graphed parametrically in
and the trace cursor is activated. When
(from the graph trace coordinates),
T=0
you can see from the table on the right
that the value of
. Press ~ to move the cursor to
( ) is
sin(T) 0
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.
9-2 Split Screen
Degree
] to display the format
editor for
Y=
. Press ˜
to
cos(T) X
1T
to
sin(T)
Ymin=L2.5
Ymax=2.5
Yscl=1
Degree
( ) is
X cos(T) 1
1T
Par
G.T
Par
.
Y
1T
mode
and
Y
1T