if f(x)= cos3x - 3/4 cosx , find f'(pi/6). Share with your friends Share 0 Varun.Rawat answered this We have,fx = cos3x - 34 cos xf'x =- 3 cos2x sin x + 34sin xf'π6 =- 3 cos2π6 sin π6 + 34 sin π6=-332212 + 34 12=-98 + 38 = - 68 = -34 0 View Full Answer
