Troubleshooting With The Fields Graph Format - Texas Instruments TI-89 Manual Book

Troubleshooting with the Fields Graph Format

Setting the Fields
Graph Format
What Order
Equation Are You
Graphing?
Fields=SLPFLD
If you have difficulties graphing a differential equation, this
section can help you correct the problem. Many problems may
be related to your Fields graph format setting.
From the Y= Editor, Window
Editor, or Graph screen, press:
ƒ
9
— or —
¥ Í
TI-89:
¥
TI-92 Plus: F
If the equation is:
1st-order
2nd-order
(system of two 1st-order equations)
3rd- or higher-order
(system of three or more 1st-order
equations)
Because
Fields = SLPFLD
default setting, a common error
message is shown to the right.
When you see this or any other error message:
¦
For your order of equation, use the previous table to find the valid
settings. Change to the applicable setting.
Fields
¦
For a particular
Fields
that applies to that setting.
Use † to select one and only one 1st-order equation.
In the
Y= Editor You can enter multiple equations, but only one at a
time can be selected.
The selected equation must not refer to any other
equation in the Y= Editor. For example:
If
y1'=y2
variable
you graph.
In the Graph If the slope field is drawn but no solution curve is
screen plotted, specify an initial condition as described on
page 184.
Chapter 11: Differential Equation Graphing
Valid Fields settings are:
SLPFLD
DIRFLD
FLDOFF
is the
setting, check the following for information
, an
Undefined
error occurs when
or
FLDOFF
or FLDOFF
197