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

CBSE BoardEnglish MediumSTD 11 ScienceMathsSTD 11 - 4.1 complex nubers1 Mark
MCQ
${\left( {\frac{{1 + i}}{{1 - i}}} \right)^2} + {\left( {\frac{{1 - i}}{{1 + i}}} \right)^2}$is equal to
  • A
    $2i$
  • B
    $ - 2i$
  • ✓
    $ - 2$
  • D
    $2$
✓

Answer

Correct option: C.
$ - 2$
c
(c) ${\left( {\frac{{1 + i}}{{1 - i}}} \right)^2} + {\left( {\frac{{1 - i}}{{1 + i}}} \right)^2} = \frac{{2i}}{{ - 2i}} + \left( {\frac{{ - 2i}}{{2i}}} \right) = - 2$.

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