begin{align}
theta_f &= pi - 2 {displaystyle bigints_{r_text{min}}^infty}
cfrac{b}{r^2 left[1 - bigg(cfrac{b}{r}bigg)^2 - cfrac{2 V(r)}
{m v_0^2}right]^{frac{1}{2}}} dr nonumber \
end{align}