`cos 20^(@) cos 40^(@) cos 80^(@)=`

cos 20^(@)* cos 40^(@) * cos 60^(@) * cos 80^(@) =

Prove that cos20^(@) cos40^(@) cos80^(@) = 1/8

The value of cos 20^(@) cos 40^(@)cos 60^(@) cos 80^(@) is equal to

The value of cos 20^(@) cos 40^(@)cos 60^(@) cos 80^(@) is equal to .............. A) 1/16 B) 3/16 C) (sqrt3)/(16) D) (sqrt3)/(32)

Prove that cos 80^(@) cos40^(@)+cos40^(@) cos200^(@) +cos200^(@) cos 80^(@) = -3/4

cos 20^(@) + cos 40^(@) + cos 60^(@) +...+cos160^(@)+cos 180^(@)=

cos20 ^ (@) cos40 ^ (@) cos80 ^ (@) =

A=cos 20^(@)cos 40^(@) cos60^(@)cos 80^(@) , B=cos6^(@)cos42^(@)cos66^(@)cos78^(@) and C=cos 36^(@)cos72^(@)cos 108^(@)cos 144^(@) then