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Graphing with ti 89

  1. Feb 24, 2009 #1
    i was wondering if i could graph something like:
    2x + 3y = 7
    3y^2 + 2x^2 -3x +6 = 0

    where the function doesnt always start with plain f(x). is it possible to do this on ti 89?
  2. jcsd
  3. Feb 25, 2009 #2
    If y=f(x), then solve for y. If you're asking about things that don't have nice explicit forms, eg a 3rd degree polynomial in y, then yes, the TI-89 can solve those for you.
    Last edited: Feb 26, 2009
  4. Feb 25, 2009 #3


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    Fairly sure you can only graph explicit functions on the TI-89, so like qntty says, you'll have to solve for y (but the TI-89 will do this for you).
  5. Feb 26, 2009 #4


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    Sometimes, but not always, you can write implicitely defined functions in terms of explicit functions of a parameter. For example, you can graph x2+ y2= 1, a circle, in parametric graphing mode with x= cos(t), y= sin(t).
  6. Feb 26, 2009 #5


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    Now the TI-89 is programmable so you might search the TI site for packages you can upload to expand its capacities or write your own. At worst you can graph the inequality f(x,y) < 0 by iterating over the coordinates on the visible screen and plotting the ones satisfying the inequality. The boundary will then be your curve.
  7. Feb 26, 2009 #6
    Yes, if you want to graph an implicit equation without having to first solve for a variable, you could easily write a program to solve it and input it into Y1.
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