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