− − u 2 w + u v 2 w 3 − u v 2 w 2 + u v w 2 − u v w + u w − u + v 2 w 2 u v w 3 / 2 {\displaystyle -{\frac {-u^{2}w+uv^{2}w^{3}-uv^{2}w^{2}+uvw^{2}-uvw+uw-u+v^{2}w^{2}}{uvw^{3/2}}}}
