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Can someone help me with this sum

  1. Feb 7, 2005 #1
    sum (sin(nx)/n)
    where n goes from 1 to infinity.
    The result should be (1/2)*(pi-x) when 0(x(pi
    and -(1/2)*(pi+x) when -pi(x(0

    I need someone to show me how to attack this problem.
    Thanks
     
  2. jcsd
  3. Feb 8, 2005 #2
    sin(nx)/n = RE[e^inx/n]
    (Further Hint : log series)

    -- AI
     
  4. Feb 8, 2005 #3

    mathman

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    Correction to TenaliRaman. sin is imaginary part, cos is real part.
     
  5. Feb 8, 2005 #4

    mathwonk

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    I would try computing the fourier coefficents of x.
     
  6. Feb 9, 2005 #5
    OOPS!

    -- AI
     
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