Texas Instruments TI-89 Titanium User Manual page 358

7. Regraph the sequence.
The web plot shows how quickly the
sequence diverges to large negative
values.
Example: Oscillation
This example shows how the initial value can affect a sequence.
1. On the Y= Editor (8 #), use the same sequence defined in the divergence
example: u1(n) = 3.2u1(nN1) N .8(u1(nN1))
2. Set
Axes = TIME
3. On the Window Editor (8 $), set the Window variables.
nmin=1
nmax=100
plotstrt=1
plotstep=1
4. Graph the sequence (8 %).
Compare this graph with the
Note:
divergence example. This is the same
sequence with a different initial value.
5. On the Y= Editor, set
Sequence Graphing
.
xmin=0 ymin=0
xmax=100 ymax=5
xscl=10 yscl=1
Axes = WEB
u(n
y=x
y=3.2x
2
. Set initial value ui1 = 0.5.
u(n)
and
Build Web = AUTO
u(n 1)
N
2
N .8x
n
.
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