Consider f(x)=ln(cos2(x))f(x) = \ln(\cos^2(x))f(x)=ln(cos2(x)). Find f′(x)f'(x)f′(x).
−2tan(x)-2 \tan(x)−2tan(x)
2tan(x)2 \tan(x)2tan(x)
−2cot(x)-2 \cot(x)−2cot(x)
1cos2x\frac{1}{\cos^2 x}cos2x1