1) multiply by x-sqrt(x^2-2)/x-sqrt(x^2-2)
2) simplify
3) seperate integral i.e x/2 and - sqrt(x^2-2)/2
4) integerate direct for x/2 but use x=sqrt2sin@ using subsitution
5) integerate properly and return all function back to x using triangle =]
6) $$$$