∫ 0 1 ( e z + 1 e z + z ) = ∫ ( ( e z + 1 ) ( 1 e z + z ) ) {\displaystyle {\begin{aligned}\int _{0}^{1}\left({\frac {e^{z}+1}{e^{z}+z}}\right)&=\int _{}^{}\left((e^{z}+1)({\frac {1}{e^{z}+z}})\right)\end{aligned}}}
u = e z + z d u = e z + 1 {\displaystyle u=e^{z}+zdu=e^{z}+1}
