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Single Valued Functions

  1. Dec 10, 2011 #1
    Hello,

    I was doing problem involving Fourier Series and came across the Dirichlet conditions which say among others that the function has to be single valued in order to be able to use Fourier Series to describe it.

    What does it mean for a function to be single valued?

    Best,
    Hermes10
     
  2. jcsd
  3. Dec 10, 2011 #2

    mathman

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    It means what it says. y=f(x) is single-valued if given an x, there is only one y.

    An example which is not is f(x) = square root of x, which is double valued.
     
  4. Dec 10, 2011 #3

    eumyang

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    This isn't true. The square root function of a positive real number is defined to be always positive.

    This is different from solving equations involving square roots. For example, if x2 = 4, then there are two solutions: √4 = 2, or -√4 = -2.
     
  5. Dec 11, 2011 #4

    mathman

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    Nitpicker!!
     
  6. Dec 11, 2011 #5

    Stephen Tashi

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    "Multivalued functions" are to "functions" as "counterfeit money" is to "money".
     
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