∫(1→+∞){dx/((e^x)+(e^(2-x)))}
=∫(1→+∞){e^xdx/((e^2x)+(e^2))}
=∫(1→+∞)d(e^x)/( e^2x + e^2 )
=arctan(e^x/e) (1→+∞)
=π/2 - π/4
=π/4
∫(1→+∞){dx/((e^x)+(e^(2-x)))}
=∫(1→+∞){e^xdx/((e^2x)+(e^2))}
=∫(1→+∞)d(e^x)/( e^2x + e^2 )
=arctan(e^x/e) (1→+∞)
=π/2 - π/4
=π/4