JEE MATHEMATICS MCQ: COMPLEX NUMBERS

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Application +4 | -1

\sum\limits_{{k=1}}^6\left(\sin \left(\frac{2 k \pi}{7}\right)+i \cos \left(\frac{2 k \pi}{7}\right)\right)=

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Correct option: C

-i

Option C (-i) is correct because by converting to exponential form and using geometric series formula, the sum simplifies to -i.

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\left|\sum\limits_{r=1}^n z_r\right|

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\alpha, \beta

\gamma

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