Texas Instruments Titanium TI-89, User Manual

Page: 295 / 977

Basic Function Graphing 292
the current graphing mode. For example, in POLAR graphing mode, function names are
r1(
q
)
,
r2(
q
)
, etc.)
Defining a New Function
1. Press
8 #
to display the Y= Editor.
Note:
The function list shows abbreviated function names such as
y1
, but the entry
line shows the full name
y1(x)
.
2. Press
D
and
C
to move the cursor to any undefined function. (Use
2 D
and
2 C
to scroll one page at a time.)
3. Press
¸
or
…
to move the cursor to the entry line.
4. Type the expression to define the function.
• The independent variable in function graphing is x.
• The expression can refer to other variables, including matrices, lists, and other
functions. Only floats and lists of floats will produce a plot.
Note:
For an undefined function, you do not need to press
¸
or
…
. When you
begin typing, the cursor moves to the entry line.
5. When you complete the expression, press
¸
.
Plots — You can scroll above y1= to see
a list of stat plots.
Function List — You can scroll through
the list of functions and definitions.
Entry Line — Where you define or edit the
function highlighted in the list.