Find the derivative of f(x)=1x2+1f(x) = \frac{1}{x^2 + 1}f(x)=x2+11 using the chain rule.
−2x(x2+1)2\frac{-2x}{(x^2 + 1)^2}(x2+1)2−2x
2x(x2+1)2\frac{2x}{(x^2 + 1)^2}(x2+1)22x
−1(x2+1)2\frac{-1}{(x^2 + 1)^2}(x2+1)2−1
−2xx2+1\frac{-2x}{x^2 + 1}x2+1−2x