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Existence-Uniqueness problems.

  1. Sep 15, 2009 #1
    Hello.

    I can't do Integral(1/ln(y)dy). Can you guys help me out?

    This is the original problem.

    In each of these IVPs, determine whether or not the Existence-Uniqueness Theorom guarantees a unique solution.

    1. dy/dx = ln(y), y(0)=0
    2. dy/dx = ln(y), y(1)=1

    Thanks.
     
  2. jcsd
  3. Sep 15, 2009 #2

    Hurkyl

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    Why does that matter? What is the "Existence-Uniqueness theorem"?

    (I assume by "do" you mean "rewrite as an algebraic combination of elementary functions"?)
     
  4. Sep 15, 2009 #3
    Solve for differential equation to find a unique solution. In order to solve the equation, I have to integrate it but I don't know how to do it.
     
  5. Sep 15, 2009 #4

    Hurkyl

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    Then find another way to answer the question you were asked!

    What is the "Existence-Uniqueness theorem"?
     
  6. Sep 15, 2009 #5

    Hurkyl

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    P.S. even if you could rewrite this integral in terms of elementary functions, I don't think that would answer the question you were asked....
     
  7. Sep 16, 2009 #6

    HallsofIvy

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    Hurkyl's point is that you do NOT need to solve the equation to "determine whether or not the Existence-Uniqueness Theorom guarantees a unique solution."

    Answer his first question: What is the "Existence-Uniqueness Theorem"? What are it hypotheses.
     
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