If `alpha` is an `n^(th)` roots of unity, then `1+2alpha+3alpha^(2)+……..+nalpha^(n-1)` equals

If alpha is an imaginary fifth root of unity, then log_(2)|1+alpha+alpha^(2)+alpha^(3)-1/alpha|=

If 1,alpha,alpha^(2),......alpha^(n-1) are n,n^(th) roots ofunity, then 1+2 alpha+3 alpha^(2)+4 alpha^(3)+......+n terms is equal to

If alpha(!=1) is a nth root of unity then S=1+3 alpha+5 alpha^(2)+......... upto n terms is equal to

If alpha!=1 is a fifth root of unity,then log_(sqrt(3))|1+alpha+alpha^(2)+alpha^(3)-(2)/(alpha)|=

If alpha is a non-real fifth root of unity, then the value of 3^(|1+alpha+alpha^(2),alpha^(-2)-alpha^(-1)| , is

If 1,alpha_(1),alpha_(2),alpha_(3),...,alpha_(n-1) are n, nth roots of unity, then (1-alpha_(1))(1-alpha_(2))(1-alpha_(3))...(1-alpha_(n-1)) equals to

If alpha is the nth root of unity,then 1+2 alpha+3 alpha^(2)+rarr n terms equal to a.(-n)/((1-alpha)^(2)) b.(-n)/(1-alpha^(2)) c.(-2n)/(1-alpha) d.(-2n)/((1-alpha)^(2))

If 1,alpha_1, alpha_2, …alpha_(n-1) be nth roots of unity then (1+alpha_1)(1+alpha_2)……....(1+alpha_(n-1))= (A) 0 or 1 according as n is even or odd (B) 0 or 1 according as n is odd or even (C) n (D) -n