Texas Instruments TI-89 Voyage 200, User Manual

Page: 444 / 1008

Differential Equation Graphing 444
By moving the trace cursor to trace each solution to
xc = 40
, you can find that:
• The exact solution (
y1
) is 85.8486, rounded to six digits.
• The
RK
solution (
Plot 1
) is 85.8952.
• The
Euler
solution (
Plot 2
) is 85.6527.
You can also use the
Data/Matrix Editor
to open the errorlog data variable and scroll to
time = 40
.
Example of the deSolve( ) Function Example of the deSolve( ) Function Example of the deSolve( ) Function Example of the deSolve( ) Function
The
deSolve( )
function lets you solve many 1st- and 2nd-order ordinary differential
equations exactly.
20. Press
…
to trace, and then press
C
or
D
until
y1
is selected. (1 shows in upper
right corner.) Then enter 40.
RK (Plot 1)
Euler (Plot 2)
Exact solution (y1)
y1 is selected when
1 shows here