Quick, need help with two indefinite integrals!
 

Can anyone integrate these? They have stumped me! Any help would be appreciated :D

1 / (1 + e^x)

and

(e^x) / (1 + e^2x)

try

http://www.integrals.com

to get the answers you are looking for.

For the second integral, use u substitution:

/
|e^x
|-------------dx
|1+e^(2x)
/


/
|e^x dx
|--------------
|1+(e^x)^2
/

Now, let u = e^x
so du = e^x dx

Substituting, we have:

/
|1
|------------du
|1 + u^2
/


= arctan(u) + C

= arctan(e^x) + C