Well here is my two cents. I do think that more people should post there math programs but, like me most people never get around to it. Also I write my programs for fun and not for money. If I do not like a program that I download I change it to suit my needs or I do not use it. Finally, all of the "advanced math" you people are trying do on the TI-85 and saying it can not do it, I wonder why? It is only one of the oldest graphing calculators that TI makes. Go and buy the TI-89 I got mine two days ago it is great.

Hey, don't dis my good friend, the TI-85! It's been with me for 2 years, and it's my buddy. *hiss* And I refuse to acknowledge the existence of the TI-89. The TI-92+ can do everything it does, and more. Now, to find a 92+ Module....

yeah 92+ are great. it does everything the 89 does, just for $50 more a and the fact most high schools don't allow it for use and it's not allowed on standardized tests. This doesn't make much cents to use considering most of the ti users are high school kids. Btw, you should cut down on your cockiness, if you don't like a program, don't use it. Youre not better than all of us because you are in this top of the line math class.

Sheesh! There's no respect for a nerd nowadays. If you're in a higher math level than everyone else, you're SUPPOSED to brag. That's the point of being smart. (And no, I'm not being sarcastic. In my school the people in the higher math classes get well-deserved respect. Now if only programmers would get some respect too...)

Here's an idea for article writers and others to consider: don't tell programmers what to do unless you're paying them or they ask you. That's all I care about in this argument.

I'm about half finished with a physics program,
but I don't have access to a physics book any longer.
If someone wants to help me out, email me. Also, Requests are VERY welcome.
The program has every equation i've come across, if you would like a specific equation included, drop me an email.

Yeah. Kewl. Okay! (A copy of this has been sent by Email to Tim).
My PRIME2 factored that baby in 10 minutes flat. Its first factor is 55511. Its second factor is 314159. Both of those turn out to be prime. You may be surprised to know that your algorith "divide by two then by the odds" is nothing other than Baby Trial Divide. :-D Thus my Wheel Factorization, or Enhanced Trial Divide, as I call it, is over 2x faster.
Right now, I can't think about trig, I like calc more.... so:

You should add "solid of revolution" to your calc program. You should add "length of an arc" to your calc program. By the way, the TI-85 has a builtin function for the length of an arc. I also can't remember synthetic division. Uh oh.

Okay, now for the long-held secret of Wheel Factorization. (Your program actually does this, but in the lowest case, so I don't count it as such.) I'm posting this to the Comments so everyone can learn this:

Let's begin with the simple case, that you use. Hope you know what mod is!

All primes are congruent to 1, mod 2, except for 2 itself. Thus you can divide by 2 (taking note if the number IS 2), and then by all the numbers that are congruent to 1, mod 2. I.E. The odd numbers.
All primes are congruent to 1 or 5, mod 6, except for 2 and 3. Thus you can divide by 2 and 3 (taking note if the number IS 2 or 3) and then by all the numbers that are congruent to 1 or 5, mod 6. Thus 5,7,11,13, and so on. (Notice how not ONLY do you skip the evens there, you skip all the multiples of 3! Right arm! Farm out!)
All primes are congruent to 1,7,11,13,17,19,23,29, mod 30, except for 2,3,and 5. Thus you can divide by 2,3,and 5 (taking note if the number IS blah blah) and then by all the numbers that are congruent to 1,7,11,13,17,19,23,29, mod 30. Now you're skipping a whole load of numbers. Right arm!
Now, to show you exactly WHAT the heck is going on here, take the special case of 2 and 5.
All primes are congruent to 1,3,7,9 mod 10. Thus you can divide by 2 and 5 (taking note blah blah) and then by all the numbers that are congruent to 1,3,7,9 mod 10. This is simply the "last digit" of the number.
If we keep all the primes in order (like 30=2*3*5) then the "congruent" thing will always be primes, you can see the pattern for yourself. With 2 and 5, 3 has been skipped, and you MUST allow the 9 mod 10 in there. (cause 19 = 9 mod 10). The obvious next case is 210, but I didn't have time to implement that in my PRIME2. PRIME2 should be up by now. If it isn't, it will be soon. It uses the mod 30 case.
:-D
STL

That is known as the sieve of Eratosthenes, created by Eratosthenes of Cyrene, an ancient Greek mathematician. Give it the proper name seeing as you are in all these advanced math classes, Mrs. Rant.
A better, simpler way to state it is as follows:

Remove multiples of all primes less than or equal to the square root of n to get all the prime numbers.
start with 2, remove 2(2), 3(2), 4(2), 5(2)...then go to 3: remove 2(3), 3(3), 4(3), 5(3)...then do 5 and 7 etc.

I agree that there is a serious lack of good math programs for the ti-85 and ti-92. I have both calcs and haven't seen a math program worthy of keeping on my calc. In fustration I bought a Hp48GX and and it was the best thing I ever did. The Hp48 GX has a tremendous amount of math and science related programs (much of which is avialable at http://hp48.ml.org/ ) and the rpl programing language makes it easy to make your own math programs. In addition to the great math and science programs that are availble for the hp48GX there are numerous well written text, data, and spreed sheet editors (that are compatible with pc spreedsheet programs that exept a tabulated text input file).

Well, it seems your article has gotten a pretty big response. Has anyone else noticed the sudden increase in math/science programs?

ive had many good math programs on my site for a while.
go there and get some, then email me what you think.

Yes, I was surprised. I thought that because this article was more specialized, more "nerdy", that it would get a smaller response than the first. Yet they got about equal response. *hmmm* Anyways, I'm pleasantly surprised. My next article has been written, but because of a bug, I'm going to revise it so it's under 8K. Again, I expect a smaller response, but who knows? :-D Ah, I'm happy just when I write them.

good article

If any one wants to know, there ARE people who develop math and science programs. I do. While I may not put out programs and functions very fast, I have a job (maybe some people have heard of this?) and cannot spend all day just...how was that? "shaving off 11 bytest"?
If anyone has any ideas for math-related programs, let me know. I'll be more than happy to help you develop it, or do it myself in my free time.

Woe! Woe to those helpless people who might actually have to do the work themselves instead of relying upon the benevolence of a programmer who has better things to do with his/her time! Oh, please! No offense, but:
1. People should be doing the work themselves anyway,
so who cares?
2. Actually, there are plenty of good programs out
there. For example, I have written nth degree
synthetic division and rational zero test programs.
No, they're not up here on ticalc.org yet, but my
point remains.

As a member of my school's math team, I write plenty of useful math programs, especially on the 89. I currently have written a converter for bases between 2 and 36, a polygon area finder (for any convex polygon with given coordinates entered in any order it will evaluate the area, or will let you know if the polygon is not convex; after finding the area it can draw the polygon for you on the graph screen), a draw function (enter just about any equation, such as the general form of a conics plot, etc.., and it will graph it for you), some prime number-related stuff, and things of that nature.

However, they are generally only other members of our math team that use these programs, certainly not because they can't do these things on their own, but only because my programs do it a bit faster. In my opinion, these programs belong to our team, and they are not the kinds of things I would like to give any chance at working against us by making them available to rival schools. So I do not post them.

I have a feeling this may be true for other math programmers...

...Not that my programs would have the slightest chance of deciding a competition - they're honestly not that amazing... but it just doesn't seem tasteful to have something I've written running on the other side of the team round.

I agree that there are not enough math and science programs. My AP Calc teacher and I have made a few good programs for Calculus. Though they are not availible on the internet they can be obtained through me. Most of these programs will run on a 85 or 86. Integraf--A program that Integrates by graphing (LRSUM,RRSUM,MRSUM,TRAP,SIMP). Plus others.

I know this is off topic but I don't know where else to put this. Is there a program for the TI-86 that can factor like the TI-89 or TI-92? Onw of my friends has a TI-92 and al he has to do is put in the factor program and then type x2-7x+28 and it'll give him the answer in this form: (x- )(x- ). He can type anything he wants and it'll give him the answer. If anyone has a program like this please e-mail me. Thanks

I have one for the TI-83, but not the 86. Oh well.

Dear Mr. Precision Fanatic,
To how many decimal places do you write pi to in math?

A. 5 million
B. 10 million
C. 15 million
D. 20 million

:-)> bearded man

Infinite. Pi has no end for decimals

20; that's how many I memorized. Lol.