We have, z1‌‌=x1+iy1 z2‌‌=x2+iy2 z3‌‌=x1+‌
ix2
2
z4‌‌=2y1+iy2 |z1|‌‌=1,|z2|=2‌ and ‌Re(z1z2)=0 ‌ Let ‌z1=eiα‌ and ‌z2=2eiβ z1z2‌‌=2ei(α+β) z1z2‌‌=2(cos(α+β)+i‌sin(α+β)) Re(z1+z2)=2&‌cos(α+β)=0 ∴‌‌α+β=‌