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I'm working through Chandrasekhar's http://prola.aps.org/abstract/RMP/v15/i1/p1_1" [Broken] and can not understand the steps to progress through Eq. (66) in Chapter 1. The integral is:

[tex]\prod^{N}_{j=1} \frac{1}{l^{3}_{j}|\rho|}\int^{\infty}_{0} sin(|\rho|r_{j})r_{j}\delta (r^{2}_{j}-l^{2}_{j})dr_{j} = \prod^{N}_{j=1} \frac{sin(|\rho|l_{j})}{|\rho|l_{j}}[/tex]

Could anyone show the steps on how this result was obtained? I am aware of how to simplify a dirac delta that is composed of a function, but it does not lead me to the above result. Thanks.

-kmd

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Integration of dirac delta composed of function of integration variable

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