SLOPE FIELD - TI 89 or TI 92

Introduction
This program plots the slope field for the differential equation in the form ${\hbox{dy}\over \hbox{dx}}=\hbox{f(x,y)}$ .

If you have not used one of the programs posted on this website before, you should read through the information in the Intro to Programming section first.

If you have a TI Connectivity Cable, you can download the program main.slopef.89p

The Program

:slopef( ) {This will already appear if you named the program slopef}

:Prgm {This will already appear}

:FnOff {FnOff is in the CATALOG menu}

:setMode("Graph", "Function") {setMode is in the F6 menu under D}

:7*(xmax-xmin)/83 $\to$ g {xmax xmin can be typed in letter by letter} { $\to$ is STO}

:7*(ymax-ymin)/55 $\to$ h

:1/(0.4*g)^2 $\to$ a

:1/(0.4*h)^2 $\to$ b

:xmin+0.5*g $\to$ x

:ymin+0.5*h $\to$ z

:For k,1,12 {For EndFor is in the F2 menu} {The 1 is a one}

:z $\to$ y

:For j,1,8

:y1(x) $\to$ t {y1 is the Y followed by a 1}

:1/ $\sqrt{}$ (a+b*t^2) $\to$ c { $\sqrt{}$ is square root}

:t*c $\to$ s

:Line x-c,y-s,x+c,y+s {Line is in the CATALOG menu}

:y+h $\to$ y

:EndFor

:x+g $\to$ x

:EndFor

:EndPrgm {This will already appear}

Running the Program

You will need to enter a function f(x,y) into y1 and adjust the WINDOW accordingly before running the program.

:slopef( )	{This will already appear if you named the program slopef}
:Prgm	{This will already appear}
:FnOff	{FnOff is in the CATALOG menu}
:setMode("Graph", "Function")	{setMode is in the F6 menu under D}
:7*(xmax-xmin)/83 $\to$ g	{xmax xmin can be typed in letter by letter} { $\to$ is STO}
:7*(ymax-ymin)/55 $\to$ h
:1/(0.4*g)^2 $\to$ a
:1/(0.4*h)^2 $\to$ b
:xmin+0.5*g $\to$ x
:ymin+0.5*h $\to$ z
:For k,1,12	{For EndFor is in the F2 menu} {The 1 is a one}
:z $\to$ y
:For j,1,8
:y1(x) $\to$ t	{y1 is the Y followed by a 1}
:1/ $\sqrt{}$ (a+b*t^2) $\to$ c	{ $\sqrt{}$ is square root}
:t*c $\to$ s
:Line x-c,y-s,x+c,y+s	{Line is in the CATALOG menu}
:y+h $\to$ y
:EndFor
:x+g $\to$ x
:EndFor
:EndPrgm	{This will already appear}