# Thread: Integrating a chain

1. ## Integrating a chain

Hi all,

Does anybody know how I might integrate this:

1 / [(1-x^2)^1/2] ??

i.e. One over the square root of (1 minus x squared). As you can tell I haven't yet learnt how you make it look all mathsy on these applets.

Any help appreciated.

Cheers.

2. Originally Posted by DangerousDave
Hi all,

Does anybody know how I might integrate this:

1 / [(1-x^2)^1/2] ??

i.e. One over the square root of (1 minus x squared). As you can tell I haven't yet learnt how you make it look all mathsy on these applets.

Any help appreciated.

Cheers.
Let $\displaystyle x=\sin(\theta)$. You'll get quite a satisfying result.

3. Thanks for the hint. That leaves me at integrating sec(x), right? - I've had a little scout around and that seems like rather a complex (though ultimately manageable) affair. I just wanted to check that the task is as I've pictured it (I'm perplexed because this seems like a much harder problem than any of the other problems on this paper)

Edit: I mean sec theta

4. Originally Posted by DangerousDave
Thanks for the hint. That leaves me at integrating sec(x), right? - I've had a little scout around and that seems like rather a complex (though ultimately manageable) affair. I just wanted to check that the task is as I've pictured it (I'm perplexed because this seems like a much harder problem than any of the other problems on this paper)

Edit: I mean sec theta
Close. You forgot to account for $\displaystyle dx=\cos(\theta)\text{ }d\theta$

5. Duh me! So it all comes out at inverse sin of x (plus c) ?

6. Originally Posted by DangerousDave
Duh me! So it all comes out at inverse sin of x (plus c) ?
!

7. Many thanks for your help!