# Thread: Integral

1. ## Integral

Hello!
$\displaystyle \int{\frac{dx}{x\sqrt{x^2-2x-1}}}$

Using the Euler substitutions $\displaystyle \sqrt{x^2-2x-1} = t-x$, I come up with the result $\displaystyle 2\arctan{(\sqrt{x^2-2x-1}+x)}.$Is the result right? I'm kinda suspicious!

Thanks

2. Your answer is correct.