Question
Question: \(\sin\pi/14.\sin 3\pi/14.\sin 5\pi/14.\sin 7\pi/14.\sin 9\pi ⥂ /1 ⥂ 4.\sin 11\pi/14.\sin 13\pi/14\)...
sinπ/14.sin3π/14.sin5π/14.sin7π/14.sin9π⥂/1⥂4.sin11π/14.sin13π/14is equal
To
A
81
B
161
C
321
D
641
Answer
641
Explanation
Solution
sin14π.sin143π.14sin5π.sin147π.sin149π.sin1411π.sin1413π= sin14π.sin143π.sin145π×1×sin(π−145π).sin(π−143π).sin(π−14π) = [sin14π.sin143π.sin145π.sin147π]2=641.