ibx=Integrate[z*Cos[theta]/(x^2+z^2+a^2-2*a*x*Cos[theta])^(3/2),theta];
bx=Evaluate[(ibx/.{theta->Pi})-(ibx/.{theta->0})]
ibz=Integrate[(-x*Cos[theta]+a)/(x^2+z^2+a^2-2*a*x*Cos[theta])^(3/2),theta];
bz=Evaluate[(ibz/.{theta->Pi})-(ibz/.{theta->0})]
A=Integrate[Cos[theta]/(x^2+z^2+a^2-2*a*x*Cos[theta])^(1/2),theta];
Atheta=Evaluate[(A/.{theta->Pi})-(A/.{theta->0})]
ADx=Integrate[(a*Cos[theta]-x)*Cos[theta]/(x^2+z^2+a^2-2*a*x*Cos[theta])^(3/2),theta];
ADx=Evaluate[(ADx/.{theta->Pi})-(ADx/.{theta->0})]
