Texas Instruments Titanium TI-89, User Manual

Page: 441 / 977

Differential Equation Graphing 438
If You Use the Table Screen to View Differential Equations
You can use the Table screen to view the points for a differential equation graph.
However, the table may show different equations than those graphed. The table shows
only the selected equations, regardless of whether those equations will be plotted with
your current
Fields
and
Axes
settings
With custom
axes If X Axis is not t, you must enter at least one initial condition
for each equation in the Y= Editor (whether the equation is
selected or not).
Otherwise, a Diff Eq setup error occurs when you graph.
In the Graph
screen If no curve is graphed, set an initial condition. If you did enter
initial conditions in the Y= Editor, select
ZoomFit :
@ „
j
A
A 1st-order equation may look different with FLDOFF than
with SLPFLD. This is because FLDOFF uses the
tplot and
tmax Window variables (page 9), which are ignored with
SLPFLD.
Notes For 1st-order equations, use FLDOFF and Axes = Custom to
plot axes that are not possible with SLPFLD. For example,
you can plot t vs. y1' (where SLPFLD plots t vs. y1). If you
enter mulNotele 1st-order equations, you can plot one
equation or its solution vs. another by specifying them as the
axes.