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