Prove that:
`sinpi/7+sin(2pi)/(7) + sin(8pi)/7 + sin(9pi)/7=0`

Show that : sin pi/7 *sin 2pi/7* sin3pi/7 = sqrt7/8

Show that: sin((2pi)/7)+ sin ((4pi)/7) + sin( (8pi)/7) = sqrt7/2 .

Let f(x) = ax^2 + bx + c where a,b,c are integers. If sin pi/7 * sin (3pi)/7 + sin (3pi)/7 * sin (5pi)/7 + sin (5pi)/7 * sin (pi)/7=f(cos (pi)/7). then find the value of f(2):

Prove that: sin^(2)pi/8+sin^(2)(3pi)/(8)+sin^(2)(5pi)/8+sin^(2)(7pi)/8=2

Prove that cos((2pi)/7) cos((4pi)/7) cos((8pi)/7) =1/8

show that sin (2 (pi) / (7)) + sin (4 (pi) / (7)) + sin (8 (pi) / (7)) = (sqrt (7)) / (2)

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

The value of 2 sin (pi/8) sin((2pi)/8) sin((3pi)/8) sin ((5pi)/8) sin ((6pi)/8) sin((7pi)/8) is :

Prove that "sin"(pi)/(14)"sin"(3pi)/(14)"sin"(5pi)/(14)"sin"(7pi)/(14)=(1)/(8)

Prove that sin^(4) pi/8+ sin^(4) 3pi/8 + sin^(4) 5pi/8 + sin^(4) 7pi/8 = 3/2 .