1. The problem statement, all variables and given/known data Integrate: (xe^x)/(sqrt[1+e^x]) 2. Relevant equations 3. The attempt at a solution I tried substituting u = e^x So the equation became: Integrate: ln|u|/sqrt[1+u] But... That doesn't help me. Trig substitution doesn't really help, neither does partial fractions. By parts doesn't work because of the fraction... So there's GOT to be a substitution I can't see.