Indefinite integral help...

uman

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

rock.freak667

complete the square of the quadratic.

uman

Oh... thanks.

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

rocomath

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

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?

rocomath

Read read read! And do the practice problems :-]

Go here to see a variety of diff. methods.

http://www.mathlinks.ro/weblog_entry...=992552#992552
http://www.mathlinks.ro/weblog_entry...=992575#992575
http://www.mathlinks.ro/weblog_entry...=992703#992703

Gib Z

When it comes to integrals, its experience that really counts. Do as many integrals as you can, you'll soon learn the tricks of the trade.