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Easy math quesiton

  1. Mar 30, 2008 #1
    3(x^2)=a^2

    When are a and x whole integers?
     
  2. jcsd
  3. Mar 30, 2008 #2

    HallsofIvy

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    Science Advisor

    In what sense does this have anything to do with "Tensor Analysis and Differential geometry"? I'm moving it to "number theory".

    In any case, if 3x2= a2 for a and x integers, then we must have
    [itex]a= x\sqrt{3}[/itex] which is impossible unless x= a= 0. It implies [itex]\sqrt{3}= a/x[/itex] but [itex]\sqrt{3}[/itex] is irrational.

    The only integer solution to 3x2= a2 is x= a= 0.
     
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