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Decomposition of the wave-vector in terms of wavelength

  1. Mar 28, 2010 #1
    Im attempting a problem in relativistic optics thats asking me to write k_x, k_y and k_z in terms of lambda, c, and theta (theta being the angle between a source and an observer, at rest relative to each other). Lamda is the wavelength in this reference frame. I started off using trigonometry to say that { k_x = 2*pi*cos(theta) / lambda } and equivalent but with sin(theta) for k_y but then how do I express k_z ? i cant see hw to it without introducing an angle between the x and z axis!

    help please!
  2. jcsd
  3. Mar 28, 2010 #2


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    Hi watty! :smile:

    (have a theta: θ and a lambda: λ and a pi: π :wink:)

    uhh? :confused: you're in charge! :wink:

    so just put kz = 0. :smile:
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