t ( 1 ) 4 − 5 t ( 1 ) 3 + 9 t ( 1 ) 2 − 5 t ( 1 ) + 1 ( t ( 1 ) − 1 ) t ( 1 ) 3 / 2 {\displaystyle {\frac {t(1)^{4}-5t(1)^{3}+9t(1)^{2}-5t(1)+1}{(t(1)-1)t(1)^{3/2}}}}