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