geofísica exponencial-cosinus

E(x,y,z ) = qk·< ( (e^{ln(a)·x}+(-1)cos(x))/x ),( (e^{ln(a)·y}+(-1)cos(y))/y ),( (e^{ln(a)·z}+(-1)cos(z))/z ) >


E(0,0,0) = qk·< ln(a) , ln(a) , ln(a) >