# Integration by parts help.

1. Oct 24, 2007

### dgoudie

[SOLVED] Integration by parts help.

1. The problem statement, all variables and given/known data
I'm working on ym Math assignment, and we are currently doing Integration by parts. I haven't had too much trouble except with the last 3. Ill only post the first of those 3 for now.
I need to find $$\int$$arctan(1/x)dx

2. Relevant equations

3. The attempt at a solution
I picked u to be arctan(1/x) and dv to be 1.

so far this is what i have:
=xarctan(1/x) - $$\int$$ (-x)/(x$$^{2}$$ +1) dx

Have I done it right so far? Any tips on how to procede?

2. Oct 24, 2007

### rocomath

use a u=subt for your integral and you're done!

3. Oct 24, 2007

### dgoudie

I got xarctan(1/x) + 1/2ln(x^2 +1) + c as my final answer.

Does that look right?

4. Oct 24, 2007

### rocomath

that's what i got :-]

5. Oct 24, 2007

### dgoudie

Alright thanks a lot.

Edit Nevermind found what i was doing wrong

Last edited: Oct 24, 2007