Given the circle $x^{2}+y^{2}=r^{2}$ with two pints $A(r,0)$ and $B(-b,w)$, $b > 0$ and $w=\sqrt{r^{2}-b^{2}}$. Outside the circle, point $P(p,q)$. The locus is a line with equation: $y=-\frac{2x\left[2b^{2}r+2bp(p+r)+p^{2}(p+r)+(p-r)(q^{2}-2qw+r^{2})\right]-4b^{2}pr-2b\left[p^{3}+2p^{2}r+p(q^{2}+r^{2})+2qr(q-w)\right]-p^{4}-2p^{3}r-2p^{2}(q^{2}-qw+r^{2})+2pr(r^{2}-q^{2})-(q^{2}+r^{2})(q^{2}-2qw+r^{2})}{2\left[2b(pq+r(q-w))+p^{2}q+2pr(q-w)+q(q^{2}-2qw+r^{2})\right]}$.