( u − 1 ) ( v − 1 ) ( u 2 v − u 2 + u v 2 − 4 u v + u − v 2 + v ) u 3 / 2 v 3 / 2 {\displaystyle {\frac {(u-1)(v-1)\left(u^{2}v-u^{2}+uv^{2}-4uv+u-v^{2}+v\right)}{u^{3/2}v^{3/2}}}}
