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Homework Help: Simplify the following equation for n 1

  1. Sep 26, 2008 #1
    1. The problem statement, all variables and given/known data
    show [tex]\frac{1}{(n-1)^2} - \frac{1}{n^2} about= \frac{2}{n^3}[/tex]
    n >> 1

    2. Relevant equations



    3. The attempt at a solution
    The first thing I tried was to put the expression all into one term.
    so I got [tex]\frac{-n^2 + 3n - 1}{n^3 - 2n^2 + n}[/tex]
    Unfortunately, I'm not sure where to go next with this... I assume it has to do with n >> 1. But I really don't see how they get 2/n^3 if anything I would think -1/n ...
     
  2. jcsd
  3. Sep 26, 2008 #2

    Redbelly98

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    Re: Simplification

    How did you get your expression (in "attempt at a solution" section)? Did you try to get a common denominator?
     
  4. Sep 26, 2008 #3

    Redbelly98

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    Re: Simplification

    Wait, I see your problem.

    The 2nd term in the original expression is 1/n2, not 1/n
     
  5. Sep 26, 2008 #4
    Re: Simplification

    My apologies, I just realized I did the incorrect substitution from the original problem. I incorrectly transcribed 1/n. It should have been 1/n^2.

    I figured it out now, thanks.
     
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