i really don't know how to start them plze help me i'll give u full 10 points?

Question

the roots of eq: {(x)^n}-1=0 are called nth roots of unity. let these roots be denoted by 1,a,a1,a2........a(n-1)
1=e^(i2rpi) (r=0,1,2,3.......)

answer following-
1) value of (1-a1) (1-a2).......(1-a(n-1))is ?
2) value of sin pi/n,sin 2pi/n,sin3pi/n,........sin(n-1)pi/nis ?
3) value of a1*a2*a3*...........*a(n-1)=?
4) if a be the nth complex root of unity then (x+b)+(x2+b)a+(x3+b)a^2................+(xn+b)a^(n-1)

Answer 1

2) value of sin pi/n,sin 2pi/n,sin3pi/n,........sin(n-1... ?

Answer 2

As far as I know the nth roots of unity are given by:

real = cos(2*m*pi/n), imag=sin(2*m*pi/n)

(with m=0,1,2,3...n-1)