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