# Integration problem

1. Feb 18, 2007

### Aerosion

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

(integrate: upper limit 3; lower limit 1)(dx/((x^(1/2))(x+1))

2. Relevant equations

3. The attempt at a solution

First of all, somebody needs to show me how to get the actual integration sign to show up on the forums.

Anyway, I was pretty confused with this one. I tried making u be x+1 and du=dx, but I was afraid this wouldn't solve for the radical x that I also had. Than I tried making u be x and du be dx, but then that wouldn't solve for the x+1 that I had. I don't think I can break this up into two different equations, so I'd like some help.

2. Feb 19, 2007

### neutrino

First line of attack in such cases: Remove the radical with a "square". Try x = u2.

Btw, making the "substitution" x = u does nothing more than change the letter denoting the dummy variable.

As for getting LaTeX to work, see this thread: https://www.physicsforums.com/showthread.php?t=8997

3. Feb 19, 2007

### Gib Z

After trying that x=u^2 substitution, try integration by parts.