MCQ
$\cos 3 A$ is equal to :
  • A
    $3 \cos A-4 \cos ^3 A$
  • B
    $3 \cos A+4 \cos ^3 A$
  • $4 \cos ^3 A-3 \cos A$
  • D
    None of these

Answer

Correct option: C.
$4 \cos ^3 A-3 \cos A$
(C )

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