question_answer

If \[y=f\left( \frac{3x+4}{5x+6} \right)\] & \[f'\,(x)=\tan {{x}^{2}}\] then \[\frac{du}{dx}=\]

A) \[\tan {{x}^{3}}\]

B) \[-\,2\tan {{\left[ \frac{3x+4}{5x+6} \right]}^{2}}.\frac{1}{{{(5x+6)}^{2}}}\]

C) \[f\left( \frac{3\tan {{x}^{2}}+4}{5\tan {{x}^{2}}+4} \right)\tan {{x}^{2}}\]

D) none of these