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