− ( t ( 1 ) 2 + t ( 2 ) ) ( t ( 1 ) t ( 2 ) 2 + 1 ) t ( 1 ) 3 / 2 t ( 2 ) 3 / 2 {\displaystyle -{\frac {\left(t(1)^{2}+t(2)\right)\left(t(1)t(2)^{2}+1\right)}{t(1)^{3/2}t(2)^{3/2}}}}
