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What does this notation mean?

  1. Sep 23, 2009 #1
    u := -v

    specifically the " := "

    Here is the context. When f, g are suitably regular functions on R we can use the change of variable u:=-v etc..

    I should add that I came across this in a Fourier Transform book..

    Last edited: Sep 23, 2009
  2. jcsd
  3. Sep 23, 2009 #2


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    It usually means 'defined to be'.

    So in this context, we know what v is, and we want to define u as a new variable. So you write u := -v to let the reader know u is being defined as -v (where v has been defined previously).
  4. Sep 23, 2009 #3
    Ah... well that makes sense
    thank you very much.
  5. Sep 24, 2009 #4


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    What, you haven't learned all half-dozen (dozen?) different symbols for "defined as" yet? :p
  6. Sep 24, 2009 #5
    the program MathCad uses the ":=" to define things like variables and functions. perhaps you saw a document made with mathcad?
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