Texas Instruments TITANIUM TI-89 - Manual (Page 99)

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Steps and keystrokes Display
1. Display the MODE dialog box. For Graph
mode, select SEQUENCE .
Press 3 B 4 ¸
2. Display and clear the Y= Editor . Then
define the sequence as
u1(n) = iPart(.8…u1(nN1)+1000).
Use iPart to take the integer part of the
result. No fractional trees are harvested.
To access iPart( , you can use 2 I,
simply type it, or select it from the
CATALOG .
Press 8 # , 8 ¸ ¸ 2 I
1 4 . 8 j U1 c j N | 1 d « 1000
d ¸
3. Define ui1 as the initial value that will be
used as the first term.
Press ¸ 4000 ¸
4. Display the Window Editor . Set the n and
plot Window variables.
nmin=0 and nmax=50 evaluate the size of
the forest over 50 years.
Press 8 $ 0 D 50 D 1 D 1 D