I’ve got this tricky trig substitution that I’ve been trying to do as for my Calc II class. I think that I’ve done the substitution part right I just have no idea where to go from here. I’ve tried many routes including integrating by parts as well. Please help me thank you 1.) Original question = ∫e^x * √(1+e^2x ) dx 2.) after trig substitution = ∫tanθ *[sec〗^3 θdθ I have looked at another source for help with I believe an identical question and it integrates this and it gives me 3.) (〖sec〗^3 θ)/3 + C So I guess all I’m really asking is how they got from step two to step three.