Question

cos pi/8 cos 3*pi/8 cos 5*pi/8 cos 7*pi/8

Answer 1

cos π/8  cos 3π/8  cos 5π/8  cos 7π/8
   =  (cos π/8  cos 7π/8) ( cos 3π/8  cos 5 π/8)
   =  [cos 6π/8 - cos 8π/8]/2  [ cos 2π/8 - cos 8π/8]/2
   =  [- 1/√2 + 1 ] [1/√2 + 1] / 4
     = (1 - 1/2 ) /4
   = 1/8

Answer 2

Answer:

2

Step-by-step explanation: