`cos^2 10^@ + cos^2 50^@+ cos^2 70^@=`

The value of cos^2 5^@ + cos^2 10^@ + cos^2 15^@ + cos^2 20^@+ cos^2 70^@ + cos^2 75^@+ cos^2 80^@ + cos^2 85^@ is equal to

Prove the following : cos 10^@ cos 30^@ cos 50^@ cos 70^@ = 3/16 .

The value of cos ^(2) 10^(@) - cos 10^(@) cos 50^(@) + cos ^(2) 50^(@) is equal to

The value of cos ^(2) 10^(@) cos 50^(@) + cos ^(2) 50^(@) is equal to

Prove the following : cos 10^@ cos 50^@ cos 70^@ = sqrt3/8 .

Value of cos^(2) 5^(@) + cos^(2) 10^(@) + cos^(2) 80^(@) + cos ^(2) 85^(@) is

cos^2 20^@+cos^2 70^2 = 1 .

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

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

The value of cos^(2)10^(@)-cos10^(@) cos 50^(@) + cos^(2) 50^(@) is