Evaluate Integral for Reduced Green's Function: Semi-Infinite Plates

[AxiomOfChoice]

Can someone help me evaluate this integral?

<br /> \int\limits_{-\infty}^{\infty} dz&#039; \frac{1}{\sqrt{(x-x&#039;)^2 + (y-y&#039;)^2 + (z-z&#039;)^2}}<br />

Mathematica is telling me that this guy diverges. But it CAN'T! This is supposed to give me the reduced Green's function for two semi-infinite plates that meet at a right angle on the z-axis.

 

[mathman]

For large z' the integrand behaves like 1/|z'|, leading to divergence.

 

[Gerenuk]

It does indeed diverge.

To solve you could use
z-z&#039;=\sqrt{(x-x&#039;)^2+(y-y&#039;)^2}\sinh t