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Calculators TI-89 won't factor or expand polynomials

  1. Nov 25, 2012 #1
    When I use the factor or expand functions on my TI-89 it outputs a matrix with values that are seemingly coming from no where. For example, if I ask my calculator to expand (3-x)^2 it gives the matrix [45, 12; 12,13]. Why is it doing this? How do I fix it?
  2. jcsd
  3. Dec 11, 2012 #2
    I don't know what the problem is, but is it possible that you have something (maybe a matrix?) stored in the variable x? If x has something stored in it, the TI-89Ti evaluates the expression as though the stored value were there in place of x rather than evaluating the expression symbolically. If x does have something stored inside it, try using a Greek character such as θ (available using the diamond button and selecting the ^ key) or anything else you can find in the 2nd->char->Greek menu. An alternative to using a Greek character would be to delete the variable x from the 2nd->Var-Link menu. Let me know if that helps.
  4. Dec 11, 2012 #3
    I got notified of a response to this and see my own response is just not here / has disappeared. So.. trying again.. clearing out the X var should do the trick.
  5. Dec 11, 2012 #4
    Clearing the x variable worked. Thanks for your help!
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