`cos^(2)5^(@)+cos^(2)10^(@)+cos^(2)15^(@)+..+cos^(2)355^(@)`

cos^(2)5^(@) +cos^(2)10^(@) + cos^(2) 15^(@) +…..+cos^(2) 85^(@) + cos^(2) 90^(@) is equal to

The value of cos^(2)75^(@)+cos^(2)45^(@)+cos^(2)15^(@)-cos^(2)30^(@)-cos^(2)60^(@) is

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

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

Find the value of cos^(2)1^(@)+cos^(2)2^(@)+cos^(2)3^(@)+ -----+cos^(2)87^(@)+cos^(2)88^(@)+cos^(2)89^(@)+cos^(2)90^(@)

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

Express the rational number S=cos^(2)(10^(@))+cos^(2)(20^(@))+cos^(2)(30^(@))+...+cos^(2)(80^(@)) in lowest terms

cos^(2)75^(0)+cos^(2)15^(0)-cos75^(0)cos15^(0)=

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