0 votes 0 votes The region of the z plane for which |z-a|/|z+a| = 1 ($Re(a)$ ≠ 0) is: a) x-axis b) y axis c) The straight line z = lal d) None of the above Linear Algebra isro-ece engineering-mathematics + – sh!va asked Mar 3, 2017 • edited Mar 9, 2019 by Naveen Kumar 3 sh!va 641 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes $\begin{align*}\frac{|z-a|}{|z+a|} &= 1\\|z-a|&= |z+a|\\|z-a|^2&= |z+a|^2\\|x + iy - a|^2&= |x + iy + a|^2\\( x-a)^2 + y^2&= ( x+a)^2 + ^2\\ x^2 - 2ax + a^2&= x^2 + 2ax + a^2\\ x &= 0 \end{align*}$ So, it represents $y$ axis and the answer is B. Gaurav Sharma answered Mar 9, 2017 Gaurav Sharma comment Share Follow See all 0 reply Please log in or register to add a comment.