Texas Instruments TI-86 - Manual (Page 159)

Chapter 10: Differential Equation Graphing
147
10DIFFEQ.DOC TI-86, Chap 10, US English Bob Fedorisko Revised: 02/13/01 2:28 PM Printed: 02/13/01 3:02 PM Page 147 of 20 10DIFFEQ.DOC TI-86, Chap 10, US English Bob Fedorisko Revised: 02/13/01 2:28 PM Printed: 02/13/01 3:02 PM Page 147 of 20 10DIFFEQ.DOC TI-86, Chap 10, US English Bob Fedorisko Revised: 02/13/01 2:28 PM Printed: 02/13/01 3:02 PM Page 147 of 20
ᕧ Display the graph screen and plot the
direction field.
ᕨ Move the free-moving cursor to the initial
condition coordinates you want.
b
" # ! $
ᕩ Draw the solution. The solution lists for
x , y , and t are stored to LX , LY , and LT .
The Again? prompt is displayed and
ALPHA-lock is on for ã Y ä and ã N ä only.
♦
To use DrEqu( again with new initial
conditions, press ã Y ä, ", #, !, or $.
b
♦
To leave DrEqu( and display the GRAPH menu, press ã N ä or ..
Using ZOOM Operations
The GRAPH ZOOM menu items, except ZFIT , work the same in DifEq graphing mode as in
Func graphing mode. In DifEq graphing mode, ZFIT adjusts the graph screen in both the x
direction and y direction.
The ZOOM menu items affect only the x ( xMin , xMax , and xScl ) and y ( yMin , yMax , and yScl )
window variables. The t window variables ( tMin , tMax , tStep , and tPlot ) are not affected,
except with ZSTD and ZRCL . You may want to edit the t window variables to ensure that
sufficient points are plotted. ZSTD sets difTol=.001 and t and Q as the axes.
In the example, since no
initial conditions were set, the
equation in Q'1 is not plotted.