# Evaulating this Integral

1. Jan 22, 2012

### november1992

1. The problem statement, all variables and given/known data

http://img528.imageshack.us/img528/356/hwhelp.png [Broken]

2. Relevant equations

http://img407.imageshack.us/img407/3696/uanddu.png [Broken]

3. The attempt at a solution
This is the answer I got. I was wondering how du replaces the circled part of the question.

Last edited by a moderator: May 5, 2017
2. Jan 22, 2012

### november1992

I just came up with this information now. Is it right?

http://img851.imageshack.us/img851/3763/uandupart2.png [Broken]

Last edited by a moderator: May 5, 2017
3. Jan 22, 2012

### Staff: Mentor

You have
$$du = \frac{e^{\sqrt{x}}}{2\sqrt{x}}dx = \frac{1}{2\sqrt{x}e^{-\sqrt{x}}}dx$$

The part you have circled (and including dx) is 2du.

Last edited by a moderator: May 5, 2017
4. Jan 24, 2012

### november1992

Thanks, I get it now.