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

cos^(2)""(3pi)/(5)+cos^(2)""(4pi)/(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)

cos^(2)""(pi)/(5)+ sin^(2)""(4pi)/(5)=

Prove that: cos^(4)(pi)/(8)+cos^(4)(3 pi)/(8)+cos^(4)(5 pi)/(8)+cos^(4)(7 pi)/(8)=(3)/(2)

Evalute : "sin"^(2)(pi)/(4) + "cos"^(2) (3pi)/(4)+"cos"^(2)(5pi)/(4)+"sin"^(2)(7pi)/(4).

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

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

cos^(2)((pi)/(12))+cos^(2)((3pi)/(12))+cos^(2)((5pi)/(12))= …………