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STD 11 - 4.1 complex nubers — JEE STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceJEESTD 11 - 4.1 complex nubers4 Marks
MCQ
${\left\{ {\frac{{2i}}{{1 + i}}} \right\}^2} = $
  • A
    $1$
  • ✓
    $2i$
  • C
    $i-i$
  • D
    $1-2i $
✓

Answer

Correct option: B.
$2i$
b
(b)${\left[ {\frac{{2i}}{{1 + i}}} \right]^2} = {\left[ {\left( {\frac{{2i}}{{1 + i}}} \right)\,\left( {\frac{{1 - i}}{{1 - i}}} \right)} \right]^2} = {(i + 1)^2} = {i^2} + 1 + 2i = 2i$.

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