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