Mathematics · 2022
JEE Main · 27 June 2022, Shift 1 · Q18
The value of cos ((2 π)/7)+ cos ((4 π)/7)+ cos ((6 π)/7) is equal to:
The value of $\displaystyle \cos \left(\frac{2 \pi}{7}\right)+\cos \left(\frac{4 \pi}{7}\right)+\cos \left(\frac{6 \pi}{7}\right)$ is equal to :
Official answer
(2)
$\displaystyle -\frac{1}{2}$
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JEE Main 2022 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.