Texas Instruments TITANIUM TI-89 - Manual (Page 357)

Sequence Graphing 357
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.