− ( u − 1 ) ( v − 1 ) ( v 2 + 1 ) ( u v + 1 ) 2 u 3 / 2 v 5 / 2 {\displaystyle -{\frac {(u-1)(v-1)\left(v^{2}+1\right)(uv+1)^{2}}{u^{3/2}v^{5/2}}}}