If $\cos (A-B)=\frac{3}{5}$ and $\tan A \tan B=2$, then

JEE MATHEMATICS MCQ: TRIGONOMETRIC EQUATIONS

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Application +4 | -1

\cos (A-B)=\frac{3}{5}

and

\tan A \tan B=2

, then

View answer and explanation

Correct option: A

\cos A \cos B=\frac{1}{5}

Option A (

\cos A \cos B=\frac{1}{5}

) is correct because by using the given trigonometric identities and solving for

\cos A \cos B

, we arrive at the value of

\frac{1}{5}

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