MCQ
The value of $\cos ^2\left(\frac{\pi}{8}+\frac{x}{2}\right)-\sin ^2\left(\frac{\pi}{8}-\frac{x}{2}\right)$ is :
  • A
    $\sqrt{2} \cos x$
  • $\frac{1}{\sqrt{2}} \cos x$
  • C
    $2 \sin \frac{x}{2}$
  • D
    $2 \cos \frac{x}{2}$

Answer

Correct option: B.
$\frac{1}{\sqrt{2}} \cos x$
(B)

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