# TI-89 Titanium help

• Calculators
triden
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.

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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hpaustin
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

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!

hpaustin
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)

hpaustin
OK!, thanks a million!

z-component
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.

ajaber
Dividing Polynomials

How do u divide polynomials on the ti-89 titanium? i only no how to add and subtract it.

ajaber
still confused

I did the clean up but when i put the example in it says syntax. and i don't 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.

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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, let's 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 don't really have to assign the polynomials to variables. You can simply enter the polynomials straight into the propFrac function.

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txxp4
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 can't figure it out, any help?

hirtmd
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.

Gold Member
just got a new ti-89, wondering how to change a decimal to a fraction on it, just a simple thing and can't figure it out, any help?

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

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

calicocal
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

Gold Member
just got a new ti-89, wondering how to change a decimal to a fraction on it, just a simple thing and can't 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

hisangel
ti-89 Titanium

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

terpsnfins
hi how would i do sin^3(x) on my ti 89 because it doesn't work when i do ^3 or ^2

cozmicdork
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

jpnissan35
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.

jccumpa
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

I am trying to graph the function y1=8x*cos(x). But everytime I do an error message tells me that I have an undefined variable. I went to F6 and cleared all variables a-z but i still get this message. Any suggestions?

i2c
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

try this

factor(2x^2+17*x*y+y^2)

xy doesn't mean x*y (it does to you and me but not to the 89)

i2c
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.

Change your mode to Float 12

i2c
I am trying to graph the function y1=8x*cos(x). But everytime I do an error message tells me that I have an undefined variable. I went to F6 and cleared all variables a-z but i still get this message. Any suggestions?

1. Make sure you're in Function mode, (i.e. not Polar or Sequence, etc)
2. If that doesn't work, make sure everything you want to keep (like programs/functions, etc) are archived, and press 2nd+On+Left+Right at the same time, it will reset your calculator back to stock, then it should work!

Mentor
I am trying to graph the function y1=8x*cos(x). But everytime I do an error message tells me that I have an undefined variable. I went to F6 and cleared all variables a-z but i still get this message. Any suggestions?

1. Make sure you're in Function mode, (i.e. not Polar or Sequence, etc)
2. If that doesn't work, make sure everything you want to keep (like programs/functions, etc) are archived, and press 2nd+On+Left+Right at the same time, it will reset your calculator back to stock, then it should work!

My guess is that the calculator doesn't like 8x, and that the expression on the right should be 8*x*cos(x).

i2c
My guess is that the calculator doesn't like 8x, and that the expression on the right should be 8*x*cos(x).

8x*cos(x) graphs fine for me on my 89.

awesome123333
i am having trouble factoring :(
when i try to factor 4x^3+12x^2-8x i end up getting 4x(x-.561..)(x+3.561..)
i don't know if i have the settings wrong or something

ArcanaNoir
i am having trouble factoring :(
when i try to factor 4x^3+12x^2-8x i end up getting 4x(x-.561..)(x+3.561..)
i don't know if i have the settings wrong or something

get it off decimal mode. I don't have one, so I don't know exactly how, but that is what you need to do. My calculator (a casio classpad) refers to non-decimal mode as "standard" mode.

swimgirl
I need help with my Ti 89. When I factor or solve from the F1 algebra menu it gives me answers in matrix format. I have tried clearing memory and reformatting... Please help!

manningb57
I need help with my Ti 89. When I factor or solve from the F1 algebra menu it gives me answers in matrix format. I have tried clearing memory and reformatting... Please help!
What you need to do, is push the mode button, press f2 to go to the second page, scroll down to "Exact/Approx". You need to change this to Exact, or Auto. This should solve your problem.