JEE MATHEMATICS MCQ: TRIGONOMETRIC EQUATIONS

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Analyzing +4 | -1

S=\cos ^2 \frac{\pi}{n}+\cos ^2 \frac{2 \pi}{n}+\ldots+\cos ^2 \frac{(n-1) \pi}{n}

, then

S

equals

View answer and explanation

Correct option: C

\frac{1}{2}(n-2)

Option C (

\frac{1}{2}(n-2)

) is correct because the sum simplifies to this expression using trigonometric identities.

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