− 2 u 2 v 2 + 3 u 2 v − u 2 + u v 4 − 4 u v 3 + 7 u v 2 − 4 u v + u − v 4 + 3 v 3 − 2 v 2 u v 2 {\displaystyle {\frac {-2u^{2}v^{2}+3u^{2}v-u^{2}+uv^{4}-4uv^{3}+7uv^{2}-4uv+u-v^{4}+3v^{3}-2v^{2}}{uv^{2}}}}
