Question

77.) If for the complex numbers \( z_{1} \) and \( z_{2} \) and \( \left|1-\bar{z}_{1} z_{2}\right|^{2}-\left|z_{1}-z_{2}\right|^{2}=k\left(1-\left|z_{1}\right|^{2}\right)\left(1-\left|z_{2}\right|^{2}\right) \), then \( k \) is equal to : (A) (B) \( -1 \) (C) \( \quad 2 \) (D) 4

Answer 1

Comparing (1) and (2), it's clear that,