Let I=∫ex√ex−1ex+3 Substitute t=ex⇒dt=exdx, we get I=∫√t−1t+3dt Substitute u=√t−1⇒du=12√t−1dt, we get I=2∫u2u2+4du=2∫(1−4u2+4)du=2∫du−2∫4u2+4du=2u−4tan−1(u2)=2√t−1−4tan−1(√t−12)=2√ex−1−4tan−1(√ex−12) Therefore, ∫log50Idx=[2√ex−1−4tan−1(√ex−12)]log50=4−π