1 + [ (cos 2 theta + cos 6 theta) / cos 4 theta] = sin 3 theta / sin theta Share with your friends Share 6 Varun.Rawat answered this LHS = 1 + cos 2θ + cos 6θcos 4θ=1 + 2 cos 6θ+2θ2 cos6θ-2θ2cos 4θ=1 + 2 cos 4θ . cos 2θcos 4θ=1 + 2 cos 2θ=1 + 21 - 2 sin2θ=1 + 2 - 4 sin2θ=3 - 4 sin2θRHS = sin 3θsin θ=3 sin θ - 4 sin3θsin θ=3 - 4 sin2θHence, LHS = RHS 16 View Full Answer
