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Homework Help: Sequences in complex (just a clarifying question)

  1. Nov 22, 2011 #1
    1. The problem statement, all variables and given/known data
    (excuse lack of latex)
    show that if SUM(zn)= S and SUM(wn= T, then SUM(zn + wn) = S + T

    2. Relevant equations

    3. The attempt at a solution

    so if i'm doing this right, this is pretty easy, i think. they want me to use a theorem that says if zn=xn +iyn, and SUM(zn)= S, where S = X + iY, this happens iff SUM(xn)= X and SUM(yn)= Y.

    so my question is am i allowed to say SUM(zn + wn) = SUM(zn) + SUM(wn) = SUM(xn) + iSUM(yn) + SUM(un) + iSUM(vn)? i'm not sure if i'm violating anything by breaking it up like this. it all follows very quickly from here.

    *edit: forgot to erase double standard questions after preview
  2. jcsd
  3. Nov 23, 2011 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    You can break it up as:

    just using the property that you posted (make sure you understand why). To go further you need to do something else
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