please solve this

(a) Let wi (where i=1,2,,n ) are n distinct n-roots of wity. That means i=n1 where i=1,2,,n Show that i=1ni=0 (b) Find 4 roots of 416(1i) Question 2 (a) From Euler's formula we can write: ei=cos+isin By wing binemial and de Maiver's theorem ve com rite cos+isin=k=0nckcosnk(isin)k Define an integer m={2nifniseven2n1ifnisodd Shar that cosn=k=0mnC2k(1)kcosn2kcin2k (b) Where do the followily cres map into under mappy wie? 1. A herizontal line y=b 2. A vertial line x=a