Texas Instruments Titanium TI-89, User Manual

Page: 346 / 977

Sequence Graphing 343
If a sequence requires an initial value but you do not enter one, you will get an error
when graphing.
On the Y= Editor, Axes lets you select the axes that are used to graph the sequences.
Optionally, for sequences only, you can select different axes for the graph. TIME is the
default.
The Y= Editor maintains an independent function list for each Graph mode setting. For
example, suppose:
• In FUNCTION graphing mode, you define a set of
y(x)
functions. You change to
SEQUENCE graphing mode and define a set of
u(n)
sequences.
• When you return to FUNCTION graphing mode, your
y(x)
functions are still defined
in the Y= Editor. When you return to SEQUENCE graphing mode, your
u(n)
sequences are still defined.
Note:
You can use the
Define
command from the Home screen (see Technical
Reference ) to define functions and equations for any graphing mode, regardless of the
current mode.
Axes Description
TIME Plots n on the x axis and u(n) on the y axis.
WEB
Plots u(n
-
1) on the x axis and u(n) on the y axis.
CUSTOM Lets you select the x and y axes.