trigonometry

Hi folks, my girl friend and I recently bought a hammock for my rooftop terrace. It didn't come with extra rope, so my girl friend went to a home improvement store later that day and bought some. I told her not to be too thrifty and buy something strong, as the forces pulling at the ropes of a...

$$\int\nolimits \frac {x+1}{\sqrt{x^2-4}}dx $$ we have a formula in latex! And it only took 20 minutes :D my question.... upon attempting to intergrate this, apparently one should realise that the substitution $x=2\cosh u$ will allow an easy simplification..... but what are the...