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If Z = 1 + 2 I 1 − ( 1 − I ) 2 , Then Arg (Z) Equal

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Question

If \[z = \frac{1 + 2i}{1 - (1 - i )^2}\], then arg (z) equal

Options

  • 0

  • \[\frac{\pi}{2}\]

  • π

  • none of these.

MCQ
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Solution

0

\[\text { Let }z = \frac{1 + 2i}{1 - \left( 1 - i \right)^2}\]

\[\Rightarrow z=\frac{1 + 2i}{1 - \left( 1 + i^2 - 2i \right)}\]

\[\Rightarrow z=\frac{1 + 2i}{1 - \left( 1 - 1 - 2i \right)}\]

\[\Rightarrow z=\frac{1 + 2i}{1 + 2i}\]

\[\Rightarrow z = 1\]

\[\text { Since point (1, 0) lies on the positive direction of real axis, we have }: \]

\[ \arg (z) = 0\]

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Chapter 13: Complex Numbers - Exercise 13.6 [Page 65]

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R.D. Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.6 | Q 20 | Page 65

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