Texas Instruments TITANIUM TI-89 - Manual (Page 438)

Differential Equation Graphing 438
8. Return to the Y= Editor. Press:
,
9
— or —
@ 8 Í
Set Fields = DIRFLD .
Note: In this example, DIRFLD is used for
two related differential equations that do
not represent a 2nd-order equation.
9. Press:
@ 2 ‰
Confirm that the axes are set as shown.
10. In the Y= Editor, clear the initial conditions
for yi1 and yi2 .
11. Return to the Graph screen, which
displays only the direction field.
12. To graph a family of solutions, return to
the Y= Editor and enter the initial
conditions shown below.
yi1={2,6,7} and yi2={5,12,18}
Note: Use a list to specify more than one
initial condition.