Find the value `sin((2pi)/(7))+sin((4pi)/(7))+sin((8pi)/(7))`

Find the value of sin((pi)/(7))sin((2 pi)/(7))sin((4 pi)/(7))=

the value of sin((pi)/(7))+sin((2 pi)/(7))+sin((3 pi)/(7)) is

sin ((pi) / (7)) sin ((2 pi) / (7)) sin ((3 pi) / (7))

The value of sin""(2pi)/(7)+sin""(4pi)/(7)+sin""(8pi)/(7), is

let cos((pi)/(7)),cos((3 pi)/(7)),cos((5 pi)/(7)), the roots of equation 8x^(3)-4x^(2)-4x+1=0 then the value of sin((pi)/(14)),sin((3 pi)/(14)),sin((5 pi)/(14))

The value of sin""(pi)/(7)sin""(2pi)/(7)sin""(3pi)/(7), is

Statement I sin((2pi)/(7))+sin((4pi)/(7))+sin((8pi)/(7))=- 1/2 . Statement II cos. (2pi)/(7)+I sin . (2pi)/(7) is complex 7th root of unity.

(sin ((3 pi) / (7)) cos ((4 pi) / (7))) / (sin ((pi) / (7)))

(sin (3 (pi) / (7)) cos (4 (pi) / (7))) / (sin ((pi) / (7)))