1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Euler's Method of Trigonometric Series- Real Analysis

  1. Feb 6, 2013 #1
    1. The problem statement, all variables and given/known data

    Use Equation (1) to derive the formula: (1-a*cos(phi))/(1-2*a*cos(phi)+a^2))= 1+a*cos(phi)+a^2(cos(2phi))+a^3(cos(3phi))...


    2. Relevant equations

    Equation (1) is 1/(1-a(cos(phi)+isin(phi)))= 1+ [a(cos(phi)+isin(phi)]+ [a(cos(phi)+isin(phi)]^2 + [a(cos(phi)+isin(phi)]^3...



    3. The attempt at a solution

    I know that you are supposed to somehow use that (cos(phi)+isin(phi))^k= cos(kphi)+ isin(kphi), but I'm not sure how to go about this at all. Please help!
     
  2. jcsd
  3. Feb 6, 2013 #2
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook