Texas Instruments TITANIUM TI-89 - Manual (Page 423)

Differential Equation Graphing 423
Selecting an Initial Condition Interactively from the Graph Screen Selecting an Initial Condition Interactively from the Graph Screen Selecting an Initial Condition Interactively from the Graph Screen Selecting an Initial Condition Interactively from the Graph Screen
When a differential equation is graphed (regardless of whether a solution curve is
displayed), you can select a point on the Graph screen and use it as an initial condition.
If Fields = Do this:
SLPFLD
– or –
DIRFLD Press:
@ 2
Š
Specify an initial condition. Either:
• Move the cursor to the applicable point and press
¸
.
– or –
• For each of the two coordinates, type a value and press
¸
.
- For SLPFLD (1st-order only), enter values for t0 and
y(t0) .
- For DIRFLD (2nd-order or system of two 1st-order
equations only), enter values for both
y(t0) initial
conditions, where t0 is the value set in the Y= Editor
or Window Editor.
A circle marks the initial condition and the solution curve is
drawn.