*** Algebra Tools 86
*** Bill Karlon, III
*** v. 1.5.1
*** 11 Jan 98

*** PLEASE KEEP THIS TEXT FILE WITH THE ACTUAL PROGRAM WHEN DISTRIBUTING.

*** NOTE: Please read this file through.  It describes the program thoroughly. 
At the very least, *PLEASE* read the "CLOSING NOTES" section at the end.

*** ALSO NOTE: There *are* changes in the program description and closing section of
this readme from the previous version.  Please reread those sections.


Okay.  This is my first program for the 86...for *any* TI calc for that
matter.  But it seems to be rather effective at what it does, and I use it
pretty much daily.  Makes me wonder how I survived in a math class without 
one.  And then there's those ZTetris breaks to keep my sanity. <G>

If you take/took an algebra course, this program should be pretty much self-
explanatory when you run it.  JIC, I've included the text descriptions 
on-screen, as well as a full description here.

Bear in mind, I'm writing this *as I'm taking Alg2,* and so the program will
progress and be updated as the year goes on. :)  I'm planning to, at the end, have 
a rather efficient and effective program to assist with most of an Algebra2 course.  
Due to this fact, this program *will* be updated very regularly -- possibly as 
often as every couple weeks.  If you'd like, drop me an email at raoul@phantom.ml.org 
and I'll put you on an "update list," on which I can either alert you of a new version,
or simply send it to you.

DISCLAIMER:  This is not to be used for cheating.  I am providing this program 
to help people with their course, and *not* to cheat where not allowed.  My 
teacher does not happen to mind if I use this during class, but yours may.
In any case, I take no responsibility for what you may do with this program.
IOW, if you use it to cheat, and get caught, I don't care, and so don't sue me.
<G>  I'm just saying to be reasonable and prudent with your usage of this and
other such programs.

PROGRAM FUNCTION DESCRIPTIONS:

Okay.  This program is broken down by menu, with the menu title at the upper-
right hand corner.  These menus are as follows:

MAIN:

Slope:  This menu contains various slope formula manipulation methods.
	NOTE: Many of these functions will display *two* sets of slope and 
	y-intercept.  This is deliberate -- one is in fraction form, the other
	in decimal.  Often one is more practical to use than the other; I have
	therefore provided both for ease of operation.

	- Slope: Converts from standard (Ax+By=X) form to slope-intercept form
		 (y=mx+b)
	- Stnd:  Slope-intercept to standard form
	- Point: Gives slope from two points: can be used in conjunction with
		 one set of points, and the PtSlp function.
	- PtSlp: y-y1=m(x-x1) - When given the slope, and a set of points,
		 this function will convert to slope-intercept form, where
		 m is the slope, and x1,y1 are the given points.
		 (ie: slope 2, points (3,1) -->  y-1=2(x-3)

Cramr:  Cramer's Rule functions - these use determinates and such to solve systems of
	equations.

        - Cr2:	 The output of this function is the common (x,y) 
		 point of the two equations entered, Nx, Ny, and the determinate.
		 I'm not going into what these are; if you're in algebra, you should 
		 know. :)  
	- Cr3:   Same deal, but for systems of three equations. (x,y,z)	 

 	NOTE:   These will only report the ordered pair if the two lines intersect.  
		Otherwise, the program will report that there are either no common
		point or an infinite number of common points.  This allows you to 
		distinguish between dependant, independant, and inconsistant equations.


Okay.  That's all for now.  The program is edit-locked on the TI (hey.  it's my first 
proggy and I'd like it to stay the way it is. :) ) but the source can be viewed with
the GraphLink, and should anyone have some suggestions...I'd appreciate them.

VERSION HISTORY:
****************

0.9B -- First version: Combined Slope 86 (actually, my first first program, but never 
	released; it became *this* too quickly :) ) and a Cramer's Rule program, both 
	written by me, to create Algebra Tools 86.

1.0B -- Worked out bugs, fixed menu system.

1.1  -- Set up menu display design -- added menu name, etc.

1.2  -- *Finally* added descriptive text.

1.3  -- Fixed annoying, but harmless, cosmetic bugs.

1.4  -- I honestly forget what the change was for this version, but <shrug> doesn't 
	matter much. :)

1.5 --  Added Cr3, reorganized menus a bit.

1.5.1 - Few reported bug fixes, as well as the complete Cramer's Rule capabilities to 
	recognize parallel/congruent lines.  Also made the program 'cleaner,' as it
	now deletes all variables it uses at the end of the program.


CLOSING NOTES:
**************

And so ends this readme file.  I'd really appreciate any comments you may have.  
This *is* my first TI program, and feedback would be great.  There's really nothing 
better than when someone drops you a line with some feedback on a program, and I'm
sure any other programmers out there would understand this.

Several people pointed out a way to fix that Div by Zero thing I had problems with.  It
really was kind of a stupid mistake on my part, as the ability to detect congruent
and parallel lines is essential to a Cramer's Rule program.

Special thanks to the following people:

Brian Bock - bug reports, Cramer's Rule help, and general support

(The next two are AOL screennames.  This explains the oddness of them. :) )
AllSop911 - Cramer's Rule suggestion
Loserclan - TypoBug report

Okay.  'Tis all for now.  My babbling ends here. :)  Thanks for using Algebra Tools.

-Bk3
-raoul@phantom.ml.org