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