If `omega = "cos"(pi)/(n) + "i sin" (pi)/(n)`, then value of `1 + omega + omega^(2) +...+omega^(n-1)` is

The value of (i)^i is omega -omega^(2) pi/3 none

If w=cos""(pi)/(n)+isin""(pi)/(n) then value of 1+w+w^(2)+.......+w^(n-1) is :

Let omega_(n)=cos((2 pi)/(n))+i sin((2 pi)/(n)),i^(2)=-1 then (x+y omega_(3)+z omega_(3)^(2))(x+y omega_(3)^(2)+z omega_(3))=