#### kreil

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

The Green function for the three dimensional wave equation is defined by,

[tex]\left ( \nabla^2 - \frac{1}{c^2}\frac{\partial^2}{\partial t^2} \right ) G(\vec r, t) = \delta(\vec r) \delta(t)[/tex]

The solution is,

[tex]G(\vec r, t) = -\frac{1}{4 \pi r} \delta\left ( t - \frac{r}{c} \right )[/tex]

Here r = |r|. Use this Green function to find f(r, t) for all r and t, where f is a solution to the inhomogenous wave equation:

[tex]\left ( \nabla^2 - \frac{1}{c^2}\frac{\partial^2}{\partial t^2} \right ) f(\vec r,t) = Ae^{- \alpha r^2} \delta (t)[/tex]

**3. The attempt at a solution**

My professor did not go over this nearly at all. I need a significant amount of help getting started.

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