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