− ( v 2 − v + 1 ) ( 3 u v 2 − 3 u v + u + v 3 − 3 v 2 + 3 v ) u v 5 / 2 {\displaystyle -{\frac {\left(v^{2}-v+1\right)\left(3uv^{2}-3uv+u+v^{3}-3v^{2}+3v\right)}{{\sqrt {u}}v^{5/2}}}}