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

Prove that cos 20^@ cos 40^@ cos60^@ cos80^@=1/16

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

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

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

Prove that a) (sin3A + sinA)sinA+(cos3A-cosA) cosA=0 b) cos20^(@)cos40^(@)cos80^(@)=1/8 c) (sin8thetacostheta-sin6thetacos3theta)/(cos2thetacostheta-sin3thetasin4theta) = tan2theta

What is cos80^@ + cos 40^@ - cos20^@ equal to ?

Find the value of cos20^@. cos40^@. Cos60^@. Cos80^@

if sin2A=2sin A cos A and sin20^(@)=K then the value of cos20^(@)cos40^(@)cos80^(@)cos160^(@)-

Prove that cos 20^(@)cos40^(@)cos60^(@)cos80^(@)=(1)/(16)