Differences In Sequence And Function Graphing - Texas Instruments TI-89 Manual Book

Differences in Sequence and Function Graphing

Setting the
Graph Mode
Defining Sequences
on the Y= Editor
Note: You must use a list to
enter two or more initial
values.
Note: Optionally, for
sequences only, you can
select different axes for the
graph. TIME is the default.
Tip: You can use the Define
command from the Home
screen (see Appendix A) to
define functions and
equations for any graphing
mode, regardless of the
current mode.
142 Chapter 9: Sequence Graphing
This chapter assumes that you already know how to graph y(x)
functions as described in Chapter 6: Basic Function Graphing.
This section describes the differences that apply to sequences.
Use 3 to set
Graph = SEQUENCE
set Window variables. The Y= Editor and the Window Editor let you
enter information for the current
If a sequence requires more than one initial value, enter them as a list
enclosed in braces { } and separated by commas.
Enter {1,0} even though
{1 0} is shown in the
sequence list.
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
graph the sequences. For more detailed information, refer to page 146.
Axes Description
TIME Plots n on the x axis and
Plots
WEB u(n-1)
Lets you select the x and y axes.
CUSTOM
The Y= Editor maintains an independent function list for each
mode setting. For example, suppose:
¦
In graphing mode, you define a set of
FUNCTION
You change to
SEQUENCE
sequences.
¦
When you return to
are still defined in the Y= Editor. When you return to
graphing mode, your
before you define sequences or
mode setting only.
Graph
You can define sequences
u1(n) through u99(n).
Use ui only for recursive
sequences, which require
one or more initial values.
lets you select the axes that are used to
u(n) on the y axis.
on the x axis and
u(n)
graphing mode and define a set of
FUNCTION graphing mode, your
sequences are still defined.
u(n)
on the y axis.
Graph
functions.
y(x)
u(n)
y(x) functions
SEQUENCE