Post your ideas for new math programs here, or build on ideas posted by other visitors.

Hi
I just started a new topic that is simulation programming on TI83.I have problem with one of the problems.It says:

"Three cars breakdown on a 500 mile-long highway.Simulate the probability they breakdown within 50 miles of each other.

I used 500rand to calculate all cars breakdown distance,then believe that I should use absolute value to make sure that they are withing 50 miles.Also, I think that probability will be the breakdowns within 50 miles divided by total number of breakdowns.
Can someone give me an idea how to connect my ideas and write program.

I have written a program on quadratics that gives the equation when 5 points are entered. I have not seen anything like it through the Archive. It works great, if the first point is (0, c). If the first point is not then the b coefficient is half of what it should be. I could write another program and correct this, but then I would have 2 programs. And I don't know how to combine them into one single program. Can someone help me? Any advice or help would be appreciated. sharon

Someone should make a Geometer's SketchPad app. Some are like it, but they aren't exactly the same. I'm in geometry, and it would help if I didn't have to go to the the PC lab every time my teacher gives us an assignment to do on SketchPad. Can anyone help, because I can't program for apps. I'm a BASIC programmer.

hey i was wondering if any of you know how to program menus, i've started messing around and programming stuff but i can't get the menu thing to work, if you could that'd be great, thanx

what does the Openlib( mean???

Can anyone come up with a program for the ti-84 calculator to get the x-intercept, discriminate, and the vertex of a quadratic equation. i have successfully coded 1/3 of my program for standard form but i can't figure out vertex form and intercept form.
Here Is My Progress:

PROGRAM:QUADRAT
:ClrHome
:Menu("EQUATION FORM?",
"STANDARD",1,
"VERTEX",2,
"INTERCEPT",3)
:Lbl 1
:Disp "STANDARD"
:Disp "AX^2+BX+C=0"
:Prompt A,B,C
:B^2-4AC->D
:Disp "XINT DIS VERTEX"

:(-B+sqrt(D))/(2A)->E
:(-B-sqrt(D))/(2A)->F
:Disp E
:Disp F
:Disp D
:Disp sqrt(D)
:-B/2A->G
:AG^2+BG+C->H
:Disp G
:Disp H
:Output(1,1,"
:Pause
:ClrHome
:Disp "AS FRACTIONS:"
:Disp E->Frac
:Disp F->Frac
:Disp D->Frac
:Disp sqrt(D)->Frac
:Disp G->Frac
:Disp H->Frac
:Output(1,1,"
:DelVar A
:DelVar B
:DelVar C
:DelVar D
:DelVar E
:DelVar F
:DelVar G
:DelVar H
:Stop

:Lbl 2
:Disp "VERTEX"
:Disp "Y=A(X-H)^2+K"
:Y=0
:Prompt A,H,K
:Disp "XINT DIS VERTEX"
:If K>0
:Then
:Y-K->B
:Else
:Y+K->B
:B/A->C
:If H>0
:Then
:sqrt(C)-H->D
:-sqrt(C)-H->E
:Else
:sqrt(C)+H->D
:-sqrt(C)+H->E
:Disp D
:Disp E
:Output(1,1,"
:Pause
:ClrHome
:Disp "AS FRACTIONS:"
:Disp D->Frac
:Disp E->Frac
:Output(1,1,"
:DelVar A
:DelVar B
:DelVar C
:DelVar D
:DelVar E
:DelVar F
:DelVar G
:DelVar H
:Stop

:Lbl 3
:Disp "INTERCEPT"
:Disp "F(X)=A(X-M)(X-N)"
:Prompt A,M,N
:Disp "XINT DIS VERTEX"
:If M>0
:Then
:B=M
:Else
:B=-M
:If N>0
:Then
:C=N
:Else
:C=-N
:Output(1,1,"
"Pause
:ClrHome
:Disp "AS FRACTIONS:"
:Output(1,1,"
:DelVar A
:DelVar B
:DelVar C
:DelVar D
:DelVar E
:DelVar F
:DelVar G
:DelVar H
:Stop
:End

Now, i am a programer with nothing to program. im in alg 2 so give me some ideas please

hi im new here but have been following this thread for a while...

i had an idea as to make a program that will first find 2 unknown numbers that add up to a number so lets say x+y=28 the program will figure out what the 2 unknows are and also those same x and y will be multiplyig to a number. so pt1: x+y=??(the number entered) and pt2 (x)(y)=!!(another number) [this part is factoring]
but i want the program to find a number that multiplys to 10 and adds up to 7

and do both parts automatically

hi im new here but have been following this thread for a while...

i had an idea as to make a program that will first find 2 unknown numbers that add up to a number so lets say x+y=28 the program will figure out what the 2 unknowns are and also those same x and y will be multiplying to a number. so pt1: x+y=??(the number entered) and pt2 (x)(y)=!!(another number) [this part is factoring]
but i want the program to find a number that multiples to 10 and adds up to 7

and do both parts automatically
Reply to this comment

Hey anyone who really knows ti-84's could u tell me if this program is possible?.... im trying to make one that tell me that root 20 is really 2 root 5 instead of 4.4721....if someone could get me started on the hard stuff such as how to plug in a number say 400 and have it search everything until it says 20 is the right awnser

I teach Algebra to students of different levels. The TI-83 has been very helpful in the past for low level students. Does anyone have any programs that may be helpful? They need to be easy to use.

I made an equation solver

Hi, I made a program that does multiple regression (when y is affected by more than one type of x-value), and it uses matrices. Currently, though, I have to enter the data into the matrices separate from the program itself. Is there any way to edit a matrix in a program? Or to edit lists and store them in a matrix? Any help would be appreciated.

Solves for when you have 2-5 equations. (though really, you can modify it to do any number)

Repeat max(A={2,3,4,5 // Asks for user input
ClrHome // until there's 2 3 4 or 5 eqs.
Input "NUMBER OF EQ'S?",A
End
{A,A+1->Dim([A] // Matrix A, not just '[' 'A' ']'
// The following is Input Code
For(C,1,A
ClrHome
For(B,1,A+1
Output(7,1,"EQUATION
Output(7,10,C
For(D,1,3A-1
Output( 8,D,sub( "AX+BY+CZ+DU+EV",D,1
End
"ABCDEF
Output( 8,3A,"="+sub( Ans,A+1,1
Input sub(Ans,B,1)+"=",E
E->[A](C,B
End
End
//End Input code
rref([A] // rref( function located under 2nd
ClrHome // matrix, math
If 1=Ans(2,A+1) and not(Ans(2,2 //Checks for no soltns
Then
ClrHome
Disp "NO SOLUTIONS
Delvar [A]Return
End
If not(Ans(2,2:Then // checks for infinite solutns
ClrHome
Disp "INFINITE SOLUTNS
Delvar[A]Return
End
//Output Code
Delvar[A]For(K,1,A
Output( K,1,sub( "XYZUV",K,1)+"=
Output(K,3,Ans(K,A+1
End
// End output code

rather condensed. only 343 bytes
any problems email: husoccer004@yahoo.com

This is for Pre-calculus...(high school pre-calc, and for college Calc , if it can be done that is)
Would someone be able to help me create a program to help test for polar symmetry? I would like to have the program test for symmetry at the X-axis, at the Y-axis, and at the origin, if possible. Thanks

Also, I was wondering, if there was A way to make a program that would help convert a point from Rectangular Coordinates-->Polar Coordinates, and Polar Coordinates-->Rectangular Coordinates.

For the conversion to Polar From Rectangular, I need it to give these 4 points...
from (X,Y) (into)-->(r,θ) it needs the following...
(r,θ)
(r,-θ)
(-r,-θ)
(-r,θ)
from Polar into Rectangular I only need the one point. thanks

I have worked on a program that will factor polynomials for the N-spire done entirely in n-spire basic. And although I do admit that this is a complex task I have quite a bit of work done on it unfortunately I don't know any algorithms to do more than factor terms in the form of (x-c) for rational c (an extension of the rational roots theorem) please help I need methods not code cause to be perfectly honest I'm writing this stuff to be fast and super optimized so that I can use it in larger programs later. I shall post my functions that comprise the program as replies because I have quite a few functions that comprise this program some of them have a couple of flaws and some of them are subject to change for optimization. comments and idea for improvement are welcome

Ok I'm working on a polynomial factoring program. But I need a better algorithm then the rational roots theorem please help. here are the funcions that make up the program. please excuse the lack of comments and insanely complex line I wrote this with efficiency in mind so it may look like a mess but its a fast mess.

this is in N-spire basic and is slightly modified by removing excessive () and again sorry about the excessively long lines
I also hope that my indenting helps despite my original code not having it for speed reasons (i know the gain is negligible but I may later build a larger system around it and when the code runs 500 times the gain no longer looks so small)
this code should run as is on N-spire OS version 2.0.0.1188
anyway enough of that heres code:
(© denotes comments. the n-sprine can take this code as is)
note: some lines are so long they wrap
replies contain code because its too long for a single post

Define polyfact( in )=
Func

Local w, x, y, z, r
polyparce( in )→in
Disp "normal form:", polygen( in )
dim( in )→x
x→r
While in[x]=0
x-1→x
EndWhile
left( in, x )→in
{1, r-x, 0}→r
If ∑( abs( fPart( in[θ] ) ), θ, 1, dim( in ) )=0 Then
in[1]→x
For y, 2, dim( in )
gcd( x, in[y] )→x
EndFor
x→r[1]
in/x→in
EndIf
sort.shell( listmult( allfact( abs( in[dim( in )] ) ), 1/allfact( abs( in[1] ) ) ) )→y
{y[1]}→z
For x, 2, dim( y )
If y[x]≠z[dim( z )]
y[x]→z[dim( z )+1]
EndFor
For w, 1, dim( z )
For x, z[w], −z[w], −2*z[w]
synthdivd( in, x )→y
While y[dim( y )]=0
r[3]+1→r[3]
augment( r, {1, x} )→r
left( y, dim( y )-1 )→in
synthdivd( in, x )→y
EndWhile
EndFor
EndFor
If dim( in )≠1 Then
augment( r, augment( {−1, dim( in )}, in ) )→r
Else
r[1]*in[1]→r[1]
EndIf
Disp "factored:"
terms2str( r )
EndFunc

Define polyparce( r )=Func
Local i, n, c, e, x, t, s
1→s
min( instr2( r, "+", 1 ), instr2( r, "-", 1 ) )→i
1→x
left( r, i-1 )→t
{expr( t )}→c
2→x
log( expr( t )/c, 2 )→e
i+1→i
While i≤dim( r )
min( instr2( r, "+", i ), instr2( r, "-", i ) )→n
1→x
ifFn( mid( r, i-1, 1 )="-", "−", "" )&mid( r, i, n-i )→t
s+1→s
expr( t )→c[s]
2→x
log( expr( t )/c[s], 2 )→e[s]
n+1→i
EndWhile
round( e, 0 )→e
©yes the rounding is nesssary it corrects for an error in the calculation of logs
newlist( max( e ) )→n
For x, 1, dim( e )
dim( n )-e[x]→i
c[x]+n[i]→n[i]
EndFor
While n[1]=0
right( n, dim( n )-1 )→n
EndWhile
n
EndFunc

Define instr2( x, y, s )=Func
inString( x, y, s )→y
ifFn( y>0, y, dim( x )+1 )
EndFunc

Define allfact( n )=Func
prmfact( n )→n
Local r, x
{1}→r
For x, 1, rowDim( n )
listmult( seq( n[x, 1]^y, y, 0, n[x, 2], sign( n[x, 2] ) ), r )→r
EndFor
r
EndFunc

©this converts the output of factor( n ) to something usable by a program
©I'm currently working on an optimizing this and adding the feture of giving factors in accenting order
©this function does more and out proforms ti's factormatrix( ) from numbtheory so thats why I'm using my own code here
©Tust me you don't want to touch this piece of code it's craziness
©I had to hand type this function so there may be mistakes
Define prmfact( n )=Func
Local r, i, t, x, d
string( factor( n ) )→r
dim( r )→i
If i≤2 ©small optimization returns quicker if value is -1, 0, 2, 3, 5, 7, 11, 13, 17, or 19
return [[expr( r )][1]]
instr2( r, "/", 2 )→x
ifFn( i>x, i-x, 0 )→t
right( r, t )→n
If left( n, 1 )="( "
mid( n, 2, t-1 )→n
left( r, x-1 )→r
ifFn( r="1", 3, 1 )→i
r&"*"&ifFn( n="", n, n&"*" )→r
{}→n
dim( r )→d
While i≤d
inString( r, "*", i )→t
iffn( t>x, "−", "" )&mid( r, i, t )→n[dim( n )+1]
t+1→i
EndWhile
dim( n )→d
seq( instring( n[i], "^" ), i, 1, d )→x
©the  in the below line are the sqrt( -1 ) not to be confused with the index used i the varible
seq( sign( expr( n[i] ) )*ifFn( x[i]=0, expr( n[i] )+, expr( left( n[i], x[i]-1 ) )+expr( right( n[i], dim( n[i] )-x[i] ) ) ), i, 1, d )→n
{real( n ), imag( n )}
EndFunc

©below function multiplys all elements in x by
©all elements in y and returns a list of the results
©mat▶list( constructMat( f( x[a], y[b] ), a, b, dim( x ), dim( y ) ) )
©is a more general form of this
Define listmult( x, y )=mat▶list( constructMat( x[a]*y[b], a, b, dim( x ), dim( y ) ) )

©below sorts a list of numbs or strings but not mixed
©and strings numbs and strings an not complex numbers
©I'm currently working on improving the speed of this code
©although it still beats TI's sort_acc( ) from numbtheory
©but then again they used a selection sort so it wasn't
©hard to beat
Define sort.shell( x )=Func
Local g, i, a, o, t, b, s, r
dim( x )→s
sort.sgap( s )→g
For a, dim( g ), 1, −1
g[a]→o
For i, o+1, s
x[i]→t
i→b
t<x[b-o]&#8594;r
While t<x[b-o]
x[b-o]&#8594;x[b]
b-o&#8594;b
If b&#8804;o
Exit
EndWhile
t&#8594;x[b]
EndFor
EndFor
x

©this function provides the most optimum know gap
©sequence for the shell sort
Define sort.sgap( a )=Func
Local g, i
{1, 4, 10, 23, 57, 132, 301, 701, 1750}&#8594;g
If a&#8804;1750
Return left( g, countIf( g, ?<a ) )
2.2*1750&#8594;i
While i<a
i&#8594;g[dim( g )+1]
round( 2.2*i, 0 )&#8594;i
EndWhile
g
EndFunc

Define polygen( x )=Func
Local r, y
dim( x )&#8594;y
ifFn( x[y]&#8800;0, ifFn( x[y]>0, "+", "-" )&string( abs( x[y] ) ), "" )&#8594;r
If dim( x )>1 Then
y-1&#8594;y
ifFn( x[y]&#8800;0, ifFn( x[y]>0, "+", "-" )&ifFn( abs( x[y] )=1, "", string( abs( x[y] ) ) )&"x", "" )&r&#8594;r
For y, y-1, 1, &#8722;1
ifFn( x[y]&#8800;0, ifFn( x[y]>0, "+", "-" )&ifFn( abs( x[y] )=1, "", string( abs( x[y] ) ) )&"x^"&string( dim( x )-y ), "" )&r&#8594;r
EndFor
EndIf
ifFn( left( r, 1 )="-", "&#8722;", "" )&right( r, dim( r )-1 )
EndFunc

Define synthdivd( p, d )=Func
Local x
For x, 2, dim( p )
p[x-1]* &#8722;d+p[x]&#8594;p[x]
EndFor
p
EndFunc

©don't ask how this function works I really don't remember
Define terms2str( t )=Func
Local r, x, e, s
""&#8594;r
ifFn( t[1]<0, "&#8722;", "" )&ifFn( abs( t[1] )=1, "", string( abs( t[1] ) ) )&#8594;r
If t[2]&#8800;0
r&ifFn( t[2]=1, "x", "x^"&string( t[2] ) )&#8594;r
3&#8594;x
1&#8594;s
While x<dim( t )
t[x]&#8594;e
s+1&#8594;s
If e<0 Then
x+1&#8594;x
t[x]&#8594;s
&#8722;e&#8594;e
EndIf
e*s+x&#8594;e
For x, x+1, e, s
r&"( "&polygen( mid( t, x, s ) )&" )"&#8594;r
EndFor
e+1&#8594;x
EndWhile
r
EndFunc

ok I made a mistake I posting not thinking I kept all the weird characters in so in all instances
&#8594; is \->\
&#952; is theda
&#8800; is =
&#8800; is not equal
&#8722; is
&#8804; is less then or equal to
&#8594; is sqrt(-1)
&#9654; is a right pointing filled in arrow
if I missed anything they are simply the numbers are simply unicode character numbers if you have an n-spire you can simply go ord(n) where n is the number between the &# and the ; sorry about that