For the function :

MATHEMATICS · Subjective · CBSE · Mathematics · Limits and Derivatives · Limits and Derivatives

Problem

For the function

f(x)=\sin(3x)+2\cos x

: (i) Obtain

f'(x)

. (ii) Calculate the numerical value of

f'\!\left(\dfrac{\pi}{3}\right)

. (iii) State whether the function is increasing or decreasing at

x=\dfrac{\pi}{3}

, giving a brief reason.