I'd have said all but there are some casio scientific calcs.

One person in my AP Calc class had a Casio with a pen that you could use on its screen. The rest had TI's. I mentioned the HP49G and no one even heard of calcs like that. I was thinking briefly about getting one in addition to the 89 but it is more expensive and with a smaller screen. I also decided that aside from games that weren't on the 89, it didn't have anything worth buying it for in my case. The only people who I can imagine would rather have one are engineering people who prefer the HP49G for those purposes.

TIs would probably dominate in my school if it wasn't for my damn math teacher who keeps bashin' TIs, claimin' that Casios are cheaper, have color, and have more features.

casios are cheaper... cheaper in every way.

Well, he/she's right. When I needed a calculator to replace my TI-83+, which I had bought for about US$120, I bought a Casio 9850LN+ for $75. After a few weeks, I found it was comparable to a TI-86, had color, and had a few extra features which were non-existant on the TI-83+ (ability to graph conics, metric unit functions, a solver like the one on the 86).
However, I later found my sister had taken my TI-83+ and left it at school (she's in 6th grade, and wanted to show it to her friends to prove you really can play games on a calculator ^_^). So now I have two calculators: my 83+ which I use regularly, and my Casio which I use on standardized tests, when I don't want to get things erased on me.

-- Nick

Slight correction. The 83 DOES have a solver like the 86. The only difference is that you can't use f(x)=g(x) as the equation, but writing it as 0=g(x)-f(x) shouldn't be any problem for anyone with any mathmatical skills.

True. I've already figured that out, but my classmates had to have it explained to them, as well as the use of the ALPHA SOLVE button.

Also, it has a slightly more user-friendly way of finding zeros of quadratic/cubic equations and solving sets of simultaneous equations.

> Also, it has a slightly more user-friendly way of finding zeros of quadratic/cubic equations

True. That POLY button has come in very handy for my DiffyQ homework. I've tried writing a program for the 83 that would solve 3rd-5th degree polynomials, but it never got released because I couldn't find a correct version of the formulas. (However, if anyone can give me the cubic and quartic formulas, I'll resume work on that program right away.)

> and solving sets of simultaneous equations.

Actually, if you know how to use the matrix editor and rref(), the 83 is just as user-friendly.

> Actually, if you know how to use the matrix editor and rref(), the 83 is just as user-friendly.

Again, I'm talking about the people who refuse to crack open the manual and need how to use the absolute value function explained to them. On the Casios, the simultaneous equation solver is accessable through the "SOLVE" icon, which is easy enough to figure out. rref( is a little more cryptic-looking.

TI could really benefit from some good competition. HP 49 is closest thing, has some fatal flaws. I'd love to design a calculator, problem is capital.

Where's the option for "I homeschool, you loser public school freak"? Eh well...

*Checks "all"*

I never even knew that casio or hp made graphing calculators until I started college. Seriously, I would see a HP49G in the store and assume it was some kind of inferior prank, as everyone in high school had TI calcs.
Now in college, there are a few people with HPs or Casios but they are razzed so much by TI owners that almost all of them seriously consider buying a TI just to see what all the fuss is about.

I have an 86 and it has served me faithfully for more than 3 years now. When I first entered high school, they recommended 83s. I did a little research and bought the 86 instead. The 86 is SO much better than the 83. It has a solver (which is SO useful in advanced math classes, saved my life several times), Tons of memory, better resolution, and better BASIC commands. I LOVE to program in BASIC, trying to get asm down but just too bogged down in homework..

I know this is nothing compared to the 89 so I'm planning on buying one soon...

I'm just rambling, I'll stop now.. My 2 cents. Tell me what do you think?

> It has a solver (which is SO useful in advanced math classes, saved my life several times),

uh, what are you talking about? The 83 has a solver too.

> Tons of memory,

True. My 83's RAM tends to fill up quickly, but my 86 has most of its RAM free. (Should have got an 83+ instead of an 83 so I could archive programs, but choosing the 83 saved me a lot of money.)

> better resolution,

Yes, there have been plenty of times my 83's screen just wasn't wide enough.

> and better BASIC commands

Afaik, the commands are exactly the same, except for some small details (for example, the Output() function is called Outpt() on the 86). So there's really no reason to say one is better. (unless you need the 83's inString() function -- some idiot decided not to include it in the 86)

So you're only half right about why the 86 is better.

Are you talking about the 83 or 83+? I'm pretty sure that the 83 doesn't have a solver.. I might be mistaken though. I haven't used an 83+ recently so I don't know if it has one or not.

Also I use the graph screen to store my math notes ( "text()" function), can the 83 do that with enough mem to spare to do complex problems? I don't think so...

> Are you talking about the 83 or 83+? I'm pretty sure that the 83 doesn't have a solver.. I might be mistaken though. I haven't used an 83+ recently so I don't know if it has one or not.

The fastest way to find out is to press [MATH][0].

> Also I use the graph screen to store my math notes ( "text()" function), can the 83 do that with enough mem to spare to do complex problems? I don't think so...

Personally, I prefer writing them on paper, so I don't know. However, recall that I actually wrote "My 83's RAM tends to fill up quickly." This means that I do recognize that 83's do not have as much RAM as I would like, which is one of the reasons I bought an 86.

The solver on the 83 is crap... It can only figure out 0=F(x)

On the 86 you can do stuff like (5)/((5x^2)-16x+2)= (34)/(53x^2) (I dont know if this works.. just made it up) and stuff like this..

>Personally, I prefer writing them on paper, so I >don't know. However, recall that I actually wrote "My >83's RAM tends to fill up quickly." This means that I >do recognize that 83's do not have as much RAM as I >would like, which is one of the reasons I bought an >86.

What I meant by putting notes on my calculator was that I was CHEATING.. in case you didn't catch my drift.. I would use those on the test when I didn't feel like memorizing tons of equations and theorems and etc.

On a side note, I'm currently in PDM (pre-calculus and discrete mathematics) and we actually are getting into more complex problems like the one above. I's like to see the 83 do THAT! MUAHAHAHAHA...

See ya.

> The solver on the 83 is crap... It can only figure out 0=F(x)

> On the 86 you can do stuff like (5)/((5x^2)-16x+2)= (34)/(53x^2)

Gee, isn't this the same as 0=34/(53x²)-5/(5x²-16x+2) ?
In which case it CAN be done on the 83.

No wonder you have to use so much memory for formulas -- you don't even remember how to do subtraction!

Btw, I'm now in Diff EQ, and until this year had NEVER seen a problem for which it was necessary to have an 86.

-- Dan B., proud owner of a TI-83 AND a TI-86

What does the 83's inString() function do?

It tells you whether and where a search string is found within a larger string, similar to the INSTR() function in QBasic or the indexOf() method in Java.

int inString(String stringToSeachIn, String stringToSearchFor, int startingPostion)

The last parameter is optional; if omitted, it is assumed to be 1.

The return value is the index of the first occurence of stringToSeachFor in stringToSearchIn, or 0 if it is not found.

Example:
:"I LOVE MY TI CALCULATORS" -> Str1
:Disp inString(Str1,"L") // displays 3 because the first occurence of "L" is at the third position in Str1
:Disp inString(Str1,"L",4) // displays 16 because the search begins at the 4th character of Str1, so the L at position 3 is ignored and the next one is at 16.
:Disp inString(Str1,"HP") // displays 0 because "HP" does not occur in Str1

TI does not seem to think this function is important, because it, because it is accessible only from the catalog on the 83 and was not included at all on the 82, 85, or 86. However, it is often a very useful function, expecially when combined with its counterpart sub(). Its applications include:

* cryptography
* database programs
* base conversion programs. For example, if Str1 represents a hex digit, then inString("0123456789ABCDEF",Str1)-1 represents the value of that digit. A hex-to-decimal converter can be made by using a loop with inString().
* conversion of text input to more useful forms.
Example: // ignore spaces, **** ticalc.org requirement
:Input "MONTH=?",Str1
:inString( "JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC" ,sub(Str1,1,3 -> P // search for user's input among list of valid values for month
:If P:Then // if found
:(P+2)/3 -> M // convert it to a 1-12 number
:Else
:expr(Str1) -> M // otherwise, assume the input is a number
:End

btw, I know a better way to cheat on math tests.

Put all your formulas in a string variable, like this:

"z=(x-mean(x))/s ME=z*sqrt(P(1-P)/n)" -> Str1

Then, in case your teacher is looking, you can show him/her a blank program screen.

On the TI-82 we stored program code inside GDB variables. In the exam, we could recal the GDB, then recall the code into a new program. The supervisors never caught us.

Your equation, properly solved.
(-170x^4-544x^3+68x^2-265) / (53*(5x^2+16x+2)=0

Umm... IT wasn't necessary to solve that equation.... It only meant to serve as an example.