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Homework Help: Derivation Sanity Check.

  1. Feb 27, 2010 #1
    I feel like an idiot asking this, but I need a check on a derivation. Can anyone verify this for me or let me know if its wrong?

    1. The problem statement, all variables and given/known data

    Expand the equation.

    2. Relevant equations

    0 = m[tex]\frac{d}{dr}[/tex]([tex]\frac{1}{r}[/tex][tex]\frac{d}{dr}[/tex](ru))

    3. The attempt at a solution

    [tex]\frac{d2u}{dr2}[/tex]+[tex]\frac{1}{r}[/tex][tex]\frac{du}{dr}[/tex]-[tex]\frac{u}{r2}[/tex] = 0


    u'' + u'/r - u/r2 = 0
  2. jcsd
  3. Feb 27, 2010 #2


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    Science Advisor
    Homework Helper

    Hi Topher925! :wink:

    Yes, that's fine. :smile:
  4. Feb 27, 2010 #3
    Crap. I was afraid someone was gonna say that.
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