`cos^2(pi/8) +cos^2((3pi)/8) +cos^2((5pi)/8)+cos^2 ((7pi)/8)=2`

Evaluate : cos^2(pi/8)+cos^2((3pi)/8)+cos^2((5pi)/8)+cos^2((7pi)/8)

Prove the following : cos^4(pi/8)+cos^4((3pi)/8)+cos^4((5pi)/8)+cos^4((7pi)/8) =3/2

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

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

Find the values: (iv) cos^(2) ((pi)/8) + cos^(2) ((3pi)/8) + cos^(2) ((5pi)/8) + cos^(2) ((7pi)/8)

Prove that cos^8(pi/8)+cos^8((3pi)/8)+cos^8((5pi)/8)+cos^8((7pi)/8)=17/16

(cos^4(pi/8))+(cos^4((3pi)/8))+(cos^4((5pi)/8))+(cos^4((7pi)/8)) is

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