Indefinite integral help

1. Jan 18, 2008

uman

How can I evaluate $\int\frac{dx}{\sqrt{1-2x-x^2}}$ using inverse trig functions? Thanks.

2. Jan 18, 2008

rock.freak667

complete the square of the quadratic.

3. Jan 18, 2008

uman

Oh... thanks.

Dang these are so hard... I wish I had the creativity to see the solution immediately like that...

4. Jan 18, 2008

rocomath

ax^2+bx+c, a=1, factor out the negative before you complete the square if you didn't remember.

5. Jan 18, 2008

uman

Thanks. I got the right answer after rock.freak667's hint. I just wish I were able to solve these more easily, without hints from this forum and elsewhere.... does it just take lots of practice, or what?

6. Jan 18, 2008

rocomath

Go here to see a variety of diff. methods.