Hi everyone.

Sorry for such a lame thread, but I feel extremely rusty with my math...

$\displaystyle \ell = 2 \cdot \int\limits_0^{ + \infty } {\frac{{\sqrt {{x^2} + 1} }}{{{{(x + 1)}^3}}}} dx$

Can you give a hint how to make this one nice and easy?

P.S. I don't think it's important, but as a matter of fact it arose from evaluating the length of a curve $\displaystyle \sqrt x + \sqrt y = 1$

Thanks!