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Vector Calculus Identity

  1. Sep 21, 2011 #1
    I am trying to figure out a proof for this identity

    [itex]\nabla[/itex](f/g) = (1/g2) (g[itex]\nabla[/itex]f - f[itex]\nabla[/itex]g)

    Any ideas?
  2. jcsd
  3. Sep 21, 2011 #2


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    It looks like a vector version of the derivative of a quotient. Look at each component separately.
  4. Sep 21, 2011 #3
    The quotient rule for ordinary derivatives:

    (f/g)' = (gf' - fg')/g2

    works for partial derivatives, too.
  5. Sep 21, 2011 #4
    Thanks so much I got it :)
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