Hence deduce that `cos(pi)/(9)cos(2 pi)/(9)cos(3 pi)/(9)cos(4 pi)/(9)=(1)/(16)`

Show that cos Acos ((pi)/(3)+A)cos ((pi)/(3)-A)=(1)/(4) cos 3A Hence deduce that cos.(pi)/(9) cos. (2pi)/(9)cos. (4pi)/(9)=(1)/(8)

Prove that cos ""(pi)/(9) cos ""( 2pi)/(9) cos "" (3pi)/(9) cos ""(4pi)/(9) = (1)/(2 ^(4)).

The value of cos""(pi)/(9)cos""(2pi)/(9)cos""(3pi)/(9)cos""(4pi)/(9), is

Prove that "cos"(pi)/9."cos"(2pi)/9."cos"(3pi)/9."cos"(4pi)/9=1/(2^(4))

Solve cos(pi/9)+cos(pi/3)+cos((5pi)/(9))+cos((7pi)/(9)) ?

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

Show that costhetacos(60^(@)+theta)cos(60^(@)-theta)=1/4 cos3theta and hence deduce that "cos"pi/9"cos"(3pi)/9"cos"(5pi)/9"cos"(7pi)/9=1/16 (T.S.MAY-2016)

cos(pi)/(11)+cos(3 pi)/(11)+......cos(9 pi)/(11)=(1)/(2)

Prove that: 2cos (pi)/(13) cos (9 pi)/(13)(3 pi)/(13)(5 pi)/(13)=0