Texas Instruments TITANIUM TI-89 - Manual (Page 365)

Sequence Graphing 365
• Draws a y=x reference line.
• Plots the selected sequence definitions as functions, with u(n N 1) as the independent
variable. This effectively converts a recursive sequence into a nonrecursive form for
graphing.
For example, consider the sequence u1(n) = and an initial value of ui1=1 .
The TI-89 Titanium draws the y=x reference line and then plots y = .
Drawing the Web Drawing the Web Drawing the Web Drawing the Web
After the sequence is plotted, the web may be displayed manually or automatically,
depending on how you set
Build Web on the AXES dialog box.
The web:
1. Starts on the x axis at the initial value ui (when plotstrt = 1 ).
2. Moves vertically (either up or down) to the sequence.
If Build Web = The web is:
TRACE Not drawn until you press
…
. The web is then drawn
step-by-step as you move the trace cursor (you must
have an initial value before using Trace).
Note : With WEB axes, you cannot trace along the
sequence itself as you do in other graphing modes.
AUTO Drawn automatically. You can then press
…
to trace the
web and display its coordinates.
5 u1 n 1 – ( ) –
y 5 x – =