`(1+cos. ( pi)/(8))(1+ cos. ( 3pi)/(8)) ( 1+ cos. ( 5pi)/(8)) ( 1+ cos. ( 7pi)/(8))=`

The value of (1+cos (pi)/(8))(1+cos (3 pi)/(8))(1+cos (5 pi)/(8))(1+cos (7 pi)/(8)) is

(1 + cos ((pi) / (8))) (1 + cos (3 (pi) / (8))) (1 + cos (5 (pi) / (8))) (1 + cos (7 (pi) / (8))) =

Prove that: (1+cos(pi)/(8))(1+cos(3 pi)/(8))(1+cos(5 pi)/(8))(1+cos(7 pi)/(8))=(1)/(8)

cos ((pi) / (8)) cos ((3 pi) / (8)) cos ((5 pi) / (8)) cos ((7 pi) / (8)) =

Prove that : (1+cos frac (pi)(8)) (1+cos frac (3pi)(8)) (1+cos frac (5pi)(8)) (1+cos frac (7pi)(8))=1/8 .

The value of (1+(cos pi)/(8))(1+(cos(3 pi))/(8))(1+(cos(5 pi))/(8))(1+(cos(7 pi))/(8))is(a)1/4(b)3/4(c)1/8(d)3/8

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