The value of `cos(pi/19)+cos((3pi)/19)+cos((5pi)/19)+`......`+cos((17pi)/19)` is (a)`1/2` (b)0 (c)1 (d)none

The value of cos((pi)/(19))+cos((3 pi)/(19))+cos((5 pi)/(19))++cos((17 pi)/(19)) is (a) (1)/(2)(b)0(c)1 (d)none

The value of (1+cos((pi)/(9)))(1+cos((3 pi)/(9)))(1+cos((5 pi)/(9)))(1+cos((7 pi)/(9)))

The value of 2"cos"(pi)/(13)"cos"(9pi)/(13)+"cos"(3pi)/(13)+"cos"(5pi)/(13) is

cos. (3pi)/(19) + cos . (7pi)/(19) + cos. (12pi)/(19) + cos. (16pi)/(19) =

Find the value of cos((19pi)/3)

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is