Slopefields on the TI85
Given a differential equation, say y' = 3xy, here is how
to make the TI85 draw a slopefield for that differential equation.

Put the calculator into Function mode: Press [2nd] [MODE]
and select Func as shown:

We must translate the differential equation: In place of the function (y
in
this case), write y (lower case), in place of y' write
y1, and in place of the variable (x in this case), write
x. So we get y1=3xy.

Now press [GRAPH][y(x)=] and enter our differential equation
from the last step on the first line:

Press [EXIT][RANGE] to select a suitable window or range.

Press [EXIT][PRGM][NAMES] and select the SLPFE
program. Press [ENTER] to run it.
Last Modified December 3, 1998.
Prof.
Janeba's Home Page  Send comments or questions to: mjanebawillamette.edu
Department
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