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

the value of cos((pi)/(2^2)) . cos((pi)/(2^3)) . cos((pi)/(2^4)) ....... cos((pi)/(2^(10))) sin((pi)/(2^(10))) is

The value of cos""(pi)/(9)cos""(2pi)/(9)cos""(3pi)/(9), is

The value of cos""(pi)/(9)cos""(2pi)/(9)cos""(3pi)/(9), is

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

show that cos^2(pi/9)+cos^2((2pi)/9)+cos^2((4pi)/9)=3/2

The value of cos(2 pi)/(21)+cos(4 pi)/(21)+cos(6 pi)/(21)+....+cos(20 pi)/(21) is equal to

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

The value of cos (pi)/(5) . cos (2 pi)/(5). cos (4 pi)/(5) . cos (8 pi)/(5) is

Evaluate : cos^2(pi/8)+cos^2((3pi)/8)+cos^2((5pi)/8)+cos^2((7pi)/8)