" If "a=cos((8 pi)/(11))+i sin((8 pi)/(11))," then "Re(a+a^(2)+a^(3)+a^(4)+a^(5))

If alpha=cos((8 pi)/(11))+i sin((8 pi)/(11)) then Re(alpha+alpha^(2)+alpha^(3)+alpha^(4)+alpha^(5)) is

If alpha = cos((8pi)/11)+i sin ((8pi)/11) then Re(alpha + alpha^2+alpha^3+alpha^4+alpha^5) is

If alpha = cos((8pi)/11)+i sin ((8pi)/11) then Re(alpha + alpha^2+alpha^3+alpha^4+alpha^5) is

If z=cos((8 pi)/(11))+i sin((8 pi)/(11));i=sqrt(-1) , then the value of Re(z+z^(2)+z^(3)+z^(4)+z^(5)) is lambda , then 20 lambda^(2) is equal to

If alpha=cos((8pi)/11+isin((8pi)/11 then Re(alpha+alpha^2+alpha^3+alpha^4+alpha^5) is

If alpha=e^((i8 pi)/(11)), then find Re(alpha+alpha^(2)+alpha^(3)+alpha^(4)+alpha^(5))

If z= cos((8pi)/11)+isin((8pi)/11),i=sqrt(-1) then the value of Re(z+z^2+z^3+z^4+z^5) is lambda then 20lambda^2 =

let x_(1)=cos((pi)/(11))cos((2 pi)/(11))cos((3 pi)/(11))cos((4 pi)/(11))cos((5 pi)/(11)) and x_(2)=cos((pi)/(11))+cos(2(pi)/(11))+cos(3(pi)/(11))+cos(4(pi)/(11))+cos(5(pi)/(11)) then show that x_(1).x_(2)=(1)/(64)(cos ec((pi)/(22))-1)

cos ((pi) / (11)) cos ((2 pi) / (11)) cos ((3 pi) / (11)) ... cos ((11 pi) / (11)) =

cos ((pi) / (11)) cos (2 (pi) / (11)) cos (3 (pi) / (11)) cos (4 (pi) / (11)) cos (5 (pi) / (11))