the ans is 0...
bhaiya, itna fansane ki zarurat hai kya???????
differentiate with respect to x
sec−1(x−1)(x+1)+sin−1(x+1)(x−1)
sec−1(x−1)(x+1)+sin−1(x+1)(x−1)
=sec−1(1+(x−1)2)+sin−1(1+(x−1)2)
Now can you try? :)