Find the derivative of f(x)=arctan(x2−1)f(x) = \arctan(\sqrt{x^2 - 1})f(x)=arctan(x2−1) for x>1x > 1x>1.
1xx2+1\frac{1}{x\sqrt{x^2+1}}xx2+11
12xx2−1\frac{1}{2x\sqrt{x^2-1}}2xx2−11
11+x2\frac{1}{1+x^2}1+x21
1xx2−1\frac{1}{x\sqrt{x^2-1}}xx2−11