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Homework Help: Converting fifth roots from polar form to complex

  1. Dec 6, 2008 #1
    1. The problem statement, all variables and given/known data
    I am looking for the fifth roots of unity, which I believe come in the form of:

    cos(2kpi/5) + isin(2kpi/5), k=1,2,3,4,5 and when k=5, the complex number is 1.

    how do you convert the rest to complex numbers? Normally, I use common triangles like:

    45-45-90 and 30-60-90

    but I don't think there is a triangle for 2pi/5.


    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 6, 2008 #2
    I don't understand your question. cos(2kpi/5) + isin(2kpi/5) is a complex number. Do you want to convert that into polar form? It should be pretty obvious.
     
  4. Dec 6, 2008 #3
    Its obvious? I can't recall how to get it. What I meant is I wanted to put it in a +bi form. That is my problem. Sorry for stating it in a confusing manner
     
  5. Dec 6, 2008 #4

    rock.freak667

    User Avatar
    Homework Helper

    It is already in the form a+bi.
    a=cos(2kpi/5)
    b=sin(2kpi/5)
     
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