TI-89 Titanium help

  1. 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
     
    Last edited: Aug 25, 2006
  2. jcsd
  3. 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.
     
  4. Mech_Engineer

    Mech_Engineer 2,299
    Science Advisor
    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 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 http://www.ticalc.org/pub/89/basic/ 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.
     
    Last edited: Aug 30, 2006
  5. 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
     
  6. Hurkyl

    Hurkyl 16,090
    Staff Emeritus
    Science Advisor
    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!
     
  7. Thnx for the quick reply. This may be a stupid question for you , but how do I undefine x?
     
  8. go to tools (press F1 - its the menu at the top), go over to Clean Up (press F6), and hit 1: (Clear a-z)
     
  9. OK!, thanx a million!
     
  10. Make sure you never store values to the common variables like x, y, z, and t!
     
  11. Remember to put some good games on it too.
     
  12. Dividing Polynomials

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

    ranger 1,684
    Gold Member

  14. still confused

    :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.:confused:
     
    Last edited: Jan 7, 2007
  15. ranger

    ranger 1,684
    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.
     
    Last edited: Jan 7, 2007
  16. 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?
     
  17. 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.
     
  18. ranger

    ranger 1,684
    Gold Member

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

    ranger 1,684
    Gold Member

    You need the TI Connect software.
    http://education.ti.com/educationportal/sites/US/productDetail/us_ti_connect.html
     
  20. 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
     
  21. Mech_Engineer

    Mech_Engineer 2,299
    Science Advisor
    Gold Member

    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
     
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