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Homework Help: Proving Modulus of Rational Expression is Equal to 1

  1. Apr 11, 2012 #1
    1. The problem statement, all variables and given/known data

    Prove [tex]|\frac{e^{2i\theta} -2e^{i\theta} - 1}{e^{2i\theta} + 2e^{i\theta} -1}| = 1[/tex]

    2. Relevant equations

    3. The attempt at a solution

    I feel like this should be fairly simple, anyone have any hints? Also this is just one step in an attempt to solve a much larger problem, so don't feel the need to be overly cryptic. Also that means I'm not entirely sure that it's true (but I think it is).
    Last edited: Apr 11, 2012
  2. jcsd
  3. Apr 11, 2012 #2


    Staff: Mentor

    I would use the facts that ei 2θ = cos(2θ) + i sin(2θ) and ei θ = cos(θ) + i sin(θ) and see where that took me.
  4. Apr 11, 2012 #3
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