(1/x)[sqrt((x+1)/(x-1))]
you must substitute sqrt((x+1)/(x-1))
thank you but you actually did a mistake that didn't affect the result in the 2nd line
dx=-4u/(u^2-1)^2
and 3rd line you switched between the numerator and the denominator
(u^2-1)/(u^2+1)
Yep, sorry, my bad, I didn't pay enough attention, I modified it.
@andrei.frit02 no problem thanks for the reply