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MHT CET · Maths · Complex Number

Let z be the complex number with \(\operatorname{Im}(\mathrm{z})=10\) and satisfing \(\frac{2 \mathrm{z}-\mathrm{n}}{2 \mathrm{z}+\mathrm{n}}=2 i-1\), where \(i=\sqrt{-1}\), for some natural number ' n ' then

  1. A \(\mathrm{n}=20\) and \(\operatorname{Re}(\mathrm{z})=10\)
  2. B \(\mathrm{n}=20\) and \(\operatorname{Re}(\mathrm{z})=-10\)
  3. C \(\mathrm{n}=40\) and \(\operatorname{Re}(\mathrm{z})=10\)
  4. D \(\mathrm{n}=40\) and \(\operatorname{Re}(\mathrm{z})=-10\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\mathrm{n}=40\) and \(\operatorname{Re}(\mathrm{z})=-10\)

Step-by-step Solution

Detailed explanation

\(2z - n = (2i - 1)(2z + n)\) \(2z - (2i - 1)2z = n + (2i - 1)n\)