Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
Grade: 12

If Z = x + i y   and w = (1-z i ) / (z-1) and |w| =1 , then find the locus of Z.

10 years ago

Answers : (2)

Ramesh V
70 Points

putting z=x+iy in w gives        w=[(1+y)-ix]/[(x-1)+iy]

on solving gives: w=[(1+y)-ix]*[(x-1)+iy] / [(x-1)2+y2]

                          = {(x-y-1) -i(x(x-1)+y(y+1))} / [(x-1)2+y2]

as |w|=1 , so {(x-y-1)2 + (x(x-1)+y(y+1))2} = [(x-1)2+y2]2

on solving the above equation, we have

2x3+2y3+2xy(x+y)-2x2-2xy+2(x+y) = 0

which is (x+y).(x2+y2-2x+2) =0  is the locus of Z




10 years ago
mycroft holmes
272 Points

1. A lot of problems in complex numbers become easy when you do not put z = x+iy. Most of the problems can be solved by geometric interpretation or by algebraic manipulation.


2. In the previous post it has been said that the locus is (x+y)(x2+y2-2x+2) = 0. Does this correspond to any familiar geometrical object (be careful with the answer)?


Shorter solution: |1-zi| = |zi-1| = |i(z+i)| = |i| |z+i| = |z+i|.


So the given equation is |z+i| = |z-1|.


This is geometrically interpreted as: the point z is equidistant from (1,0) and (0,-1).


The locus of points equidistant from two given points is the perpendicular bisector of the line joining the two points which is nothing but the line x+y = 0


So what about the term (x2+y2-2x+2) seen in the previous thread?

10 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution

Course Features

  • 101 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details