[" 5.Prove that: "],[qquad " (i) "cos10^(@)cos30^(@)cos50^(@)cos70^(@)=(3)/(16)]

cos10^(0)cos30^(0)cos50^(@)cos70^(0)

cos 10^(@) cos 30^(@) cos 50^(@) cos 70^(@) =(3)/(16)

Prove that cos10^(@)cos30^(@)cos50^(@)cos70^(@)=(3)/(16)

Prove that cos10^(@)cos30^(@)cos50^(@)cos70^(@)=(3)/(16)

cos 10^(@) cos 30^(@) cos 50^(@) cos 70^(@) =

Prove that: cos10^(0)cos30^(@)cos50^(@)cos70^(@)=(3)/(16)

Prove that cos10^@cos30^@cos50^@cos70^@=3/(16) .

cos^(2)10^(@)+cos^(2)50^(@)+cos^(2)70^(@)=?

Prove that: i) cos10^(@)cos30^(@)cos50^(@)cos70^(@)=3/16 ii) cos20^(@)cos40^(@)cos60^(@)cos80^(@)=1/16 iii) 4cos12^(@)cos48^(@)cos72^(@)=cos36^(@) iv) cos40^(@) cos80^(@)cos160^(@)=-1/8