# TI-89 Titanium help

• Calculators
I just got a TI-89 off ebay for the upcoming school year to help with calc and engineering studies. My old calculator was a ti-83plus and I knew that baby inside and out. I am trying to become familiar with the 89 before school starts, but there is one major thing I can't really figure out (short of reading the manual :tongue: ).

When I do a calculation and enter in say 30/52, I get out 15/26 instead of a decimal number. How can I change this? Also, are there any good tutorials out there that are recommended?

Cheers,
Chris

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To get a decimal representation, press

<diamond> , <enter>

You can change the way the calculator represents numbers by pressing,

<mode>
go down to

"Exact/Approx"
and change it to auto, exact, or approximate.

you are probably in exact mode right now.

As far as tutorials go, I can't help you with that. If there is something I need (I just assume the calculator can do it), I look it up through google, or use the manual.

Mech_Engineer
Gold Member
Actually, he's probably in "auto" mode right now. You could change the mode to always spit out decimal numbers ("approx" mode), or you can just add a decimal to one of the numbers in "auto" mode.

In AUTO mode-

30/42 = 5/7

but,

30/42. = .71429

So no decimal gives you the reduced fraction, but adding a decimal point gives you the decimal number.

Also, I highly recommend www.ticalc.org[/url] for downloads of user-made programs. You can find all sorts of useful stuff there! You will find many useful math and "science" (a.k.a. engineering) programs in the [url]http://www.ticalc.org/pub/89/basic/[/URL] directories (careful you don't get distracted, there are lots of games too lol). Also take note that the TI-89 can run TI-92 Plus BASIC files, so you can look around in there too.

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TI-89 question,

Need assistance on TI-89 question, can anyone help?
When I attempt to factor, I get a numeric answer.
For example, on page 51 of manual I attempt to factor(x^2-5,x). I get 59.
thnx

Hurkyl
Staff Emeritus
Gold Member
I bet you've defined x to be 8. You need to undefine x if you want to use it as a variable!

Thnx for the quick reply. This may be a stupid question for you , but how do I undefine x?

go to tools (press F1 - its the menu at the top), go over to Clean Up (press F6), and hit 1: (Clear a-z)

OK!, thanx a million!

Make sure you never store values to the common variables like x, y, z, and t!

Remember to put some good games on it too.

Dividing Polynomials

How do u divide polynomials on the ti-89 titanium? i only no how to add and subtract it. still confused I did the clean up but when i put the example in it says syntax. and i dont get it when they say to put something about f/g? What did i do wrong? I know everything about electronics inside out but this calculator shut me up. yours truely, the confused one. Last edited:
ranger
Gold Member
Okay here is what you do [after you clear A-Z]:

1) There are two parts to the fraction, the number being dividend and the one begin the divisor. You have to assign each of these into a variable.

2)Place the divided into a variable, lets call it f. Do the following: x^4+3x^3+7x^2+7x+8 [then hit the STO key] f. Having done this, f will now have the value of the divided number. It appears like this on your screen:
x^4+3x^3+7x^2+7x+8->f

3) Do the same for the divisor. x^2+3x+4 [then hit the STO key] g. Having done this, g will now have the value of the divided number. It appears like this on your screen:
x^2+3x+4->g

4)Then hit F2 and select the desired function. For a case like this, select propFrac().

5)Then enter f/g within the parenthesis of the propFrac function:
propFrac(f/g)

You dont really have to assign the polynomials to variables. You can simply enter the polynomials straight into the propFrac function.

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decimal to fraction

just got a new ti-89, wondering how to change a decimal to a fraction on it, just a simple thing and cant figure it out, any help?

TI-89 Titanium Driver

I bought a TI-89 Titanium about a year ago, but since then I have moved from Washington (state) to Virginia. Somewhere in between here and there is the cd that came with my TI-89.
I need to hook it up to my computer for various things, and need the driver off of that cd. Is there anywhere online that would have that driver? I have thoroughly searched the TI websites and have googled my eyes out trying to find this thing. Any help is appreciated.

ranger
Gold Member
just got a new ti-89, wondering how to change a decimal to a fraction on it, just a simple thing and cant figure it out, any help?

One way of doing it is to change your mode from approximate to exact.

ranger
Gold Member
I bought a TI-89 Titanium about a year ago, but since then I have moved from Washington (state) to Virginia. Somewhere in between here and there is the cd that came with my TI-89.
I need to hook it up to my computer for various things, and need the driver off of that cd. Is there anywhere online that would have that driver? I have thoroughly searched the TI websites and have googled my eyes out trying to find this thing. Any help is appreciated.

You need the TI Connect software.
http://education.ti.com/educationportal/sites/US/productDetail/us_ti_connect.html

I am trying to do complex numbers on my calculator. For example doing 4e^(i*30°)+3e^(i*80°) and having it output in the same format. Thanks

Mech_Engineer
Gold Member
just got a new ti-89, wondering how to change a decimal to a fraction on it, just a simple thing and cant figure it out, any help?

Use the "exact()" function

Example:
Input: exact(.625)
Output: 5/8

Alternativerly, just take the decimal number divided by 10^n where n is the number of sig. figs.

Examples:

(Decimal to convert is 0.625, 3 sig figs so 10^3 = 1000)
Input: 625/1000
Ouput: 5/8 (assuming you're in "auto" mode on the calculator)

(Decimal to convert is 0.0625, 4 sig figs so 10^4 = 10000)
Input: 625/10000
Output 1/16

ti-89 Titanium

i was just wondering if anyone knew how to display residuals in the data/matrix editor

hi how would i do sin^3(x) on my ti 89 because it doesnt work when i do ^3 or ^2

This helped me out lots! I had the same problem, and I was about to sell mine because I could not get it to work! But now I get to keep my awesome calculator!
-Cozmic

When I do a compounding interest problem on my TI-89 Titanium, it returns the answer as a whole number with no decimals. I have tried changing "Exact/Approximate" in the Mode menu, "diamond"-enter, but it always rounds the answer to the next whole number. Any help with this? Thanks.

Hi, when try factor(2x^2+17xy+y^2) the result is the same equation, the same result with quadratic polynomials doesn't give a facotr answer. Thanks