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