Question

If θ₁ and θ₂ are arguments of complex numbers z₁ and z₂ respectively then prove that:
z₁\(\bar{z_2}\) + \(\bar{z_1}\)z₂ = 2|z₁||z₂| cos(θ₁ – θ₂)

Answer 1

Adding equation (i) and (ii) we get