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Calculators TI 89 Titanium Simple Question

  1. Dec 21, 2008 #1
    It says (the TI site) that the TI-89 Titanium can manipulate symbolically and what not. Well I just have 2 quick questions:

    let's say I punch in some equation like [tex]\frac{dE}{dt}=\dot{Q}-\dot{W}+\sum_i\dot{m_i}h_i-\sum_e\dot{m_e}h_e[/tex]

    1.) I could somehow select W (for example) and the calculator would know to solve the expression symbolically for W?

    2.) I could then input numerical values for all of the other variables and it would give me the numerical value of W?

  2. jcsd
  3. Dec 22, 2008 #2
    Anyone have this calculator?
  4. Dec 24, 2008 #3
    Seriously, answer me. Please :smile: So I can buy it for myself for X-mass.
  5. Dec 25, 2008 #4
    I don't know but I think you are asking for way too much ...

    I wouldn't rely on calculators for these things

    but I see that it does solve DEs
    http://www.rowan.edu/open/depts/math/HASSEN/ODE/TI89_for_ODE.pdf [Broken]

    and this says that it can solve for one variable
    http://ti-89.org/forums/post-97.html [Broken]

    then there are always limitations.. these equations need to be dumb simple

    (I only used it in grade 12 only.. now I have casio fx. It do many conversions and has constant values and solve simple algebraic, quadratic, cubic equations, etc, .. and had it for about 15$)
    Last edited by a moderator: May 3, 2017
  6. Dec 25, 2008 #5
    Asking way too much? All I want to know is if I punch in a+b+c=d can the calculator return that a=d-b-c

    and if d=1

    Can I input those and have it tell me that a=0.

    I don't think that is too much... or is it? I have never rellied on calculators to do algebra. But as an engineer entering his junior year, I am sick of doing algebra :smile:
  7. Dec 25, 2008 #6
    yep, I think so .. see that thread:

    "you can use solve() function to do it (in algebra menu), put the equation first, then a comma, the the varible you want to isolate. in your example, it would be: solve(x+y=z,x) and it will return you x=z-y. Similarly, if you want isolate y, put: solve(x+y=z,y) and it will return you y=z-x"

    I thought you wanted something like
    df/dt = Q(t) + W(t) + sigma (f(t)) + sigma (z(t))

    I been using casio for my engineering ...

    I would recommend going through all the TI manual:

    and comparing it to what you will be doing.. and if your TI calculator would be allowed in the finals.
  8. Dec 25, 2008 #7
    Cools! :smile: thanks for the links!
  9. Dec 25, 2008 #8
    Yes, I own one (for ~4 years now), and yes, it will do what you want (use the solve, nsolve, and desolve functions). Also, if you get it, download http://www.ibiblio.org/technicalc/packages/mathtools/main.htm" and install it on your ti.

    Merry schnappsmas. :cool:
    Last edited by a moderator: Apr 24, 2017
  10. Dec 25, 2008 #9
    Last edited by a moderator: Apr 24, 2017
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