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

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

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

Statement I : sin^2pi/8+sin^2(3pi)/8+sin^2(5pi)/8+sin^2(7pi)/8=2 Statement II cos^2pi/8+cos^2(3pi )/8+cos^2(5pi)/8+cos^2(7pi/8)=2 Statement III: sin^2pi/8+sin^(3pi)/8+sin^2(5pi)/8sin^2 (7pi)/8=3/2

Prove that sin pi/14* sin 3pi/14 * sin 5pi/14 = 1/8 .

Value of cos^3 (pi/8)cos^3 ((3pi)/8) + sin^3 (pi/8)sin^3 ((3pi)/8) is

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

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