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