JEE MATHEMATICS MCQ: TRIGONOMETRIC EQUATIONS

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Application +4 | -1

\cos \theta=\frac{1}{2}\left(x+\frac{1}{x}\right)

, then

\frac{1}{2}\left(x^2+\frac{1}{x^2}\right)

is equal to

View answer and explanation

Correct option: B

\cos 2 \theta

Option B (

\cos 2 \theta

) is correct because it is derived from the given equation by squaring and using the double angle formula for cosine.

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