`cos20^@cos40^@cos60^@cos80^@-1/16=`

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

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

Statement-1: The vlaue of cos20^(@)cos40^(@)cos60^(@)cos80^(@)is1/16. Statement-2: for any theta, cos thetacos(60^(@)-theta)cos(60^(@)+theta)=1/4cos3theta

A=cos20^(@)cos40^(@)cos60^(@)cos80^(@),B=cos60cos42^(@)cos66^(@)cos78^(@) and C=cos36^(@)cos72^(@)cos108^(@)cos144^(@) then

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

cos20^(@).cos40^(@).cos60^(@).cos80^(@) is :

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

The value of cos0^@ cos30^@ cos45^@ cos60^@ cos 90^@ is: cos0^@ cos30^@ cos45^@ cos60^@ cos 90^@ का मान क्या होगा ?

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

4cos6^(@)cos42^(@)cos60^(@)cos78^(@)=