If ∫01 et1+tdt=a , then ∫01 et(1+t)2dt is equal to
a−1+e2
a+1−e2
a−1−e2
a+1+e2
since, I=∫01 et1+tdt=11+tet01+∫01 et(1+t)2dt=a
Therefore, ∫01 et(1+t)2=a−e2+1