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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
$1 + {i^2} + {i^4} + {i^6} + ..... + {i^{2n}}$is
  • A
    Positive
  • B
    Negative
  • C
    Zero
  • ✓
    Cannot be determined
✓

Answer

Correct option: D.
Cannot be determined
d
(d) $S = 1 + {i^2} + {i^4} + ..... + {i^{2n}} = 1 - 1 + 1 - 1 + ...... + {( - 1)^n}$
Obviously it depends on $n$.
Hence cannot be determined unless $n$ is known.

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