Find f′(x)f'(x)f′(x) for f(x)=ln(x2+1)f(x) = \ln(x^2 + 1)f(x)=ln(x2+1).
2x2x2x
ex2+1e^{x^2 + 1}ex2+1
2x/(x2+1)2x / (x^2 + 1)2x/(x2+1)
1/(x2+1)1 / (x^2 + 1)1/(x2+1)