Question
Question: If I<sub>m</sub>\(\left( \frac{z - 1}{2z + 1} \right)\)= –4, then locus of z is-...
If Im(2z+1z−1)= –4, then locus of z is-
A
Ellipse
B
Parabola
C
Straight line
D
Circle
Answer
Circle
Explanation
Solution
Sol. Put z = x + iy
Ž Im (2x+1+2iyx−1+iy)=–4
=(2x+1)2+4y2−2y(x−1)+y(2x+1)= –4
We get 16x2 + 16y2 + 16x + 3y + 4 = 0 (Eq. of Circle)