# Help W/ Integration-Calc 1

1. Jul 23, 2008

### rockfan0005@g

Help W/ Integration--Calc 1

Hey everybody,
I have a problem that I don't know how to solve...can someone help me out:
Integral (1/(1+e^x))dx

2. Jul 23, 2008

### jeffreydk

Re: Help W/ Integration--Calc 1

Try using substitution first for $u=e^x$ which will give you

$$\int \frac{du}{u(1+u)}$$
and then use partial fractions to get some $A,B$ where

$$\int \frac{A}{u}du + \int \frac{B}{1+u}du$$

and from there try and see if you can find a solution.

3. Jul 23, 2008

### rock.freak667

Re: Help W/ Integration--Calc 1

You can use the substitution jeffreydk said or use u=1+e^x. Both are fine.

4. Jul 24, 2008

### rockfan0005@g

Re: Help W/ Integration--Calc 1

Thanks guys, so much...answer wasn't too difficult after that.