Let f(x)=(x2+1)cos(x)f(x) = (x^2+1)^{\cos(x)}f(x)=(x2+1)cos(x). Which expression represents f′(x)f'(x)f′(x)?
(x2+1)cos(x)[2xcos(x)x2+1−sin(x)ln(x2+1)](x^2+1)^{\cos(x)} \left[ \frac{2x\cos(x)}{x^2+1} - \sin(x)\ln(x^2+1) \right](x2+1)cos(x)[x2+12xcos(x)−sin(x)ln(x2+1)]
(x2+1)cos(x)[xcos(x)x2+1−sin(x)ln(x2+1)](x^2+1)^{\cos(x)} \left[ \frac{x\cos(x)}{x^2+1} - \sin(x)\ln(x^2+1) \right](x2+1)cos(x)[x2+1xcos(x)−sin(x)ln(x2+1)]
cos(x)(x2+1)cos(x)−1⋅2x\cos(x)(x^2+1)^{\cos(x)-1} \cdot 2xcos(x)(x2+1)cos(x)−1⋅2x
(x2+1)cos(x)ln(x2+1)⋅sin(x)(x^2+1)^{\cos(x)} \ln(x^2+1) \cdot \sin(x)(x2+1)cos(x)ln(x2+1)⋅sin(x)