A complex number z1 is rotated through an angle of θ clockwise, about the origin to reach z2.Then z2z1 equals to
When we rotate through an angle of θ clockwise, the multiplication factor is e−iθ
⇒ z1z2 = e−iθ
If z1 is rotated through an angle of 120∘ anti-clockwise about z0 to reach z2 , then z2−z0z1−z0 equal to