`cos 80^(@) + cos40^(@) - cos 20^(@)` किसके बराबर है ?

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

cos 40^(@) + cos 80^(@) + cos 160^(@) =

cos80 ^ (0) + cos40 ^ (@) - cos20 ^ (@) = 0

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

The value of (sin^2 60^@- cos^2 45^@+ sec 60^@+ cos^2 40^@+ cos^2 50^@) is equal to: (sin^2 60^@- cos^2 45^@+ sec 60^@+ cos^2 40^@+ cos^2 50^@) का मान किसके बराबर है?

cos20^(@)cos40^(@)cos60^(@)cos80^(@)=

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

Prove that cos80^(@)+cos40^(@)-cos20^(@)=0 .

Prove that, cos80^(@)+cos40^(@)-cos20^(@)=0