Question
if x=2Cosθ-Cos2θ and y=2Sinθ-Sin2θ prove that dy/dx=tan(3θ/2)
Joshi sir comment
calculate dx/dθ and dy/dθ
then dy/dx = [2cosθ-2cos2θ]/[-2sinθ+2sin2θ]
now solve
use cosC-cosD = 2sin[(C+D)/2]sin[(D-C)/2]
and sinC+sinD = 2sin[(C+D)/2]cos[(C-D)/2]