Texas Instruments TITANIUM TI-89 User Manual

Page 438

Differential Equation Graphing

438

8. Return to the Y= Editor. Press:

— 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.