POQis a straight line through the origin O,P and Q represent the complex numbers a+ib andc+id respectively and OP=OQ, then
a+c=b+d
(a,b) It is given that OP=OQ
∴ |¯¯¯¯¯¯¯¯OP|=|¯¯¯¯¯¯¯¯¯OQ| ⇒ |a+ib|=|c+id|
Also ¯¯¯¯¯¯¯¯OP =-¯¯¯¯¯¯¯¯¯OQ,∴ ¯¯¯¯¯¯¯¯OP + ¯¯¯¯¯¯¯¯¯OQ=0
⇒ (a+c)+i(b+d) =0 ⇒ a+c=0=b+d