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