Question
Question: The locus of z (= x + iy) which satisfies the inequality log<sub>0.3</sub> \|z – 1\| \> log<sub>0.3<...
The locus of z (= x + iy) which satisfies the inequality log0.3 |z – 1| > log0.3 |z – i| is given by –
A
x + y < 0
B
x – y > 0
C
x + y > 0
D
x – y < 0
Answer
x – y > 0
Explanation
Solution
Sol. We have log0.3 |z – 1| > log0.3 |z –i|
Ž |z – 1| < |z – i|(Q 0 < 0.3 < 1)
Ž |x + iy – 1| < |x + iy – i|
Ž (x – 1)2 + y2 < x2 + (y – 1)2
Ž x2 + y2 – 2x + 1 < x2 + y2 – 2y + 1
Ž –2(x – y) < 0 Ž x – y > 0 .