JEE Mains · Maths · STD 11 - 3. trignometrical ratios,functions and identities
If \(\sin ^{2}\left(10^{\circ}\right) \sin \left(20^{\circ}\right) \sin \left(40^{\circ}\right) \sin \left(50^{\circ}\right) \sin \left(70^{\circ}\right)=\alpha-\) \(\frac{1}{16} \sin \left(10^{\circ}\right)\), then \(16+\alpha^{-1}\) is equal to
- A \(60\)
- B \(70\)
- C \(80\)
- D \(90\)
Answer & Solution
Correct Answer
(C) \(80\)
Step-by-step Solution
Detailed explanation
\(\sin 10^{\circ}\left(\frac{1}{2} \cdot 2 \sin 20^{\circ} \sin 40^{\circ}\right) \cdot \sin 10^{\circ} \sin \left(60^{\circ}-10^{\circ}\right) \sin \left(60^{\circ}+10^{\circ}\right)\)…
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