SLOPEFLD (graph the slope field for a differential equation y f(x, y)) Input: Differential equation y f (x, y)

Output: Slope field for the differential equation

This program draws slope fields on both the TI-82 and TI-83.

Prgm SLOPFLD :10→L

:10→W :(YmaxYmin) /L→V :(XmaxXmin) /W→H :ClrDraw

:FnOff

:0→R

:YminV/2→Y

:Lbl 1

:R1→R

:0→C

:XminH/2→X

:Lbl 2

:C1→C

:Y →M 1

:M*H/4Y→S :M*H/4Y→T :XH/4→P :XH/4→Q

:If abs (TS) .7V :Goto 3

:Lbl 4

:Y→Z

:Line (P, S, Q, T) :Z→Y

:XH→X

:If CW

:Goto 2 :YV→Y :If RL :Goto 1 :Stop

:Lbl 3 :Y.35V→T :Y.35V→S :(TY) /MX→Q :(SY) / MX→P :Goto 4

Program by: Mark Howell, Gonzaga School, Washington, D.C.