Dielectric Sphere in Field of a Point Charge

Apteronotus
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Hi,
I have derived the electric potential equations inside and outside the sphere due to a point charge q placed a distance b way from the sphere's center. The potentials are given by:
\Phi_{in}(r,\theta) = \sum^{\infty}_{n=0} A_{n}r^{n}P_{n}(cos\theta)<br />
and
\Phi_{out}(r,\theta) = \sum^{\infty}_{n=0} \frac{kr^{n}}{b^{n+1}} + \sum^{\infty}_{n=0}\frac{B_{n}}{r^{n+1}}P_{n}(cos\theta)<br />

where
k=\frac{q}{4\pi\epsilon_{0}} and P_{n} - are the Legendre polynomials

I have calculated the the constants A_{n} and B_{n} according to the usual boundary conditions. Unfortunately, almost non of them are equal to zero unlike the the case of a 'sphere in a uniform field'. Is there any way of truncating these infinite sums to end up with something nice and clean?
 
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No. It is an infinite series.
 
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