If z₁,

Given z₁ and z₂ are conjugate complex numbers.

⇒ z₂ = z̅ ₁ = |z|/2pi is,

he negative side of the real axis

= r₁ (cos θ₁ - i sin θ₁)

= r₁ [cos (-θ₁) + I sin (-θ₁)]

Similarly, z₃ = r₂ (cos θ₂ - i sin θ₂)

⇒ z₄ = r₂ [cos (-θ₂) + I sin (-θ₂)]

= θ₁ – (-θ₂) + (-θ₁) – θ₂

= θ₁ + θ₂ – θ₁ – θ₂

= 0