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