Question

sin π/14 * sin 3π/14 * sin 5π /14​

Answer 1

Hello mate

Convert sin 3pi/14 into cos 4pi/14.

Convert sin 5pi/14 into cos 2pi/14

now problem has become sin pi/14 cos 4pi/14 cos 2pi/14

assume pi/14 as x

sin x cos 2x cos 4x

divide and multiply by cos x and 2

(2sin x cos x cos 2x cos 4x)/2 cos x

2 sin 2x cos 2x cos 4x/4 cos x

sin 4x cos 4x 2 / 8 cos x

sin 8x/8 cos x

(sin 8pi/ 14)/8 cos pi/14

convert sin 8pi/14 into cos pi/14

so

1/8

Hope this helps you.....