Question

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

Answer 1

I can do this because I want + cos 3A weight and 1 + cos 3 pi by 8 and 1 + cos 5 8 8 7 3 8 is equal to 1 by 10 is very useful for all and I can be your answer