AP EAMCET · Maths · Trigonometric Ratios & Identities
\(\cos 12^{\circ} \cdot \cos 24^{\circ} \cdot \cos 36^{\circ} \cdot \cos 48^{\circ} \cdot \cos 72^{\circ} \cdot \cos 84^{\circ}=\)
- A \(\frac{1}{32}\)
- B \(\frac{1}{16}\)
- C \(\frac{1}{64}\)
- D \(\frac{1}{128}\)
Answer & Solution
Correct Answer
(C) \(\frac{1}{64}\)
Step-by-step Solution
Detailed explanation
\(\begin{aligned} & \text {} \cos 12 \cos 24 \cos 36 \cos 48 \cos 72 \cos 84 \\ & =\frac{2 \sin 24 \cos 24 \cos 36 \cos 48 \cos 72 \cos 84}{4 \sin 12} \\ & =\frac{-2 \sin 48 \cos 48 \cos 36 \cos 72 \cos (180-84)}{8 \sin 12}\end{aligned}\)…
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