Q45Multiple choice
cos 2θ cos 2φ + sin2 (θ – φ) – sin2 (θ + φ) is equal to
- (A)sin 2(θ + φ)
- (B)cos 2(θ + φ)
- (C)sin 2(θ – φ)
- (D)cos 2(θ – φ) 2 2 [Hint: Use sin A – sin B = sin (A + B) sin (A – B)]
cos 2θ cos 2φ + sin2 (θ – φ) – sin2 (θ + φ) is equal to