`cos^(2)((3 pi)/(5))+cos^(2)((4 pi)/(5))=`

5.if the expression cos^(2)((pi)/(11))+cos^(2)((2 pi)/(11))+cos^(2)((3 pi)/(11))+cos^(2)((4 pi)/(11))+cos^(2)((5 pi)/(11)) has the value equal to p/q in it lowest from ; then find (p+q)

Show that if n>2cos^(2)((pi)/(n))+cos^(2)((3 pi)/(n))+cos^(2)((5 pi)/(n))+...nterms=(n)/(2)

THe value of cos^(2)((pi)/(12))+cos^(2)((pi)/(4))+cos^(2)((5 pi)/(12)) is

What is the value of expression cos^(2)((pi)/(8))+4cos^(2)((pi)/(4))-sec((pi)/(3))+5tan^(2)((pi)/(3))+sin^(2)((pi)/(8)) ?

cos^(-1)((3)/(5))+cos^(-1)((4)/(5))=(pi)/(2)

The value of cos^(2)((pi)/(20))+cos^(2)((2 pi)/(20))+cos^(2)((3 pi)/(4))+......+cos^(2)((9 pi)/(20)) is

Find the value of cos^(2)(pi)/(16)+cos^(2)(3 pi)/(16)+cos^(2)(5 pi)/(16)+cos^(2)(7 pi)/(16)

cos ((pi) / (15)) cos ((2 pi) / (15)) cos ((3 pi) / (15)) cos ((4 pi) / (15)) cos ((5 pi) / (15)) cos ((6 pi) / (15)) cos ((7 pi) / (15)) = (1) / (1)

Prove that: cos^(2)pi/8 + cos^(2)(3pi)/(8) + cos^(2)(5pi)/(8)+ cos^(2)(7pi)/(8)=2