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Homework Help: Dirac Delta in polar coordinates

  1. Jul 8, 2010 #1
    1. The problem statement, all variables and given/known data

    Hi, I would like to know what is the right way to write continous deltas standing in a circle of radius a?

    2. Relevant equations



    3. The attempt at a solution

    I am not sure weather it's δ(r-a) or is it
    δ(r-a)/|r-a|
    Thank you
     
  2. jcsd
  3. Jul 8, 2010 #2

    hunt_mat

    User Avatar
    Homework Helper

    You know that:
    [tex]
    f(x,y)=\int_{-\infty}^{\infty}f(u,v)\delta (x-u)\delta (y-v)dxdy
    [/tex]
    Now make a change of co-ordinates from Cartesian to polar, and the answer should drop out for you. Failing that look it up on Wikipedia :eek:)

    Mat
     
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