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Homework Help: De Moivre's Theorem

  1. Jun 4, 2012 #1
    1. The problem statement, all variables and given/known data

    Find what the following formula yields if we substitute q= E(Φ)

    the formula is:1+2q+3q^2+...+nq^n-1=(1-(n+1)q^n+nq^n+1)/(1-q^2)

    2. Relevant equations

    3. The attempt at a solution

    i substituted Φ in for q:

    1+2E( Φ)+3E( Φ)^2+...+nE( Φ)^n-1= (1-(n+1)E( Φ)^n +nE( Φ)^n+1)/(1-E( Φ)^2)

    now I'm not sure where to go next
  2. jcsd
  3. Jun 4, 2012 #2
    What is E(Φ) supposed to be??
  4. Jun 4, 2012 #3
    e of phi
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