Originally Posted by

**JustMeAgain** I have looked at trig substitution as you suggested, but have not come to the same conclusion. I found that:

$\displaystyle \displaystyle \int \frac{1}{\sqrt{1-x^2}}~dx = \int \cos(t)~dx = sin(t) + C$

where $\displaystyle t=\tan^{-1}x$

but this may still need some work, and I'm not sure whether I'm stuck on that approach.

However, I am unclear about what you mean with your x in $\displaystyle \sin^{-1}x$. Do you mean the k I used in the word document? or do you mean something completely different?

JustMeAgain