Texas Instruments TITANIUM TI-89 User Manual
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106
2. Display and clear the
Y= Editor
. Then
define the 1st-order differential equation:
y1'(t)=.001y1…(100Ny1)
Press
p to enter the … shown above. Do
not use implied multiplication between the
variable and parentheses. If you do, it is
treated as a function call.
Leave the initial condition
yi1
blank.
Note:
With y1' selected, the device will
graph the
y1
solution curve, not the
derivative y1'.
Press
8 # , 8 ¸ ¸ .001 Y1
p c 100 | Y1 d ¸
3. Display the
GRAPH FORMATS
dialog box.
Then set
Axes = ON
,
Labels = ON
,
Solution
Method = RK
, and
Fields = SLPFLD
.
Note:
To graph one differential equation,
Fields must be set to
SLPFLD
or
FLDOFF
.
If
Fields=DIRFLD
, an error occurs when
you graph.
Press
8 Í D D B 2 D D B 2 D B 1
D B 1 ¸
Steps and keystrokes
Display