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