Question

if omega is a complex cube root of unity, show that (2-omega)(2-omega²)=7​

Answer 1

Step-by-step explanation:

(2-w)(2-w²)=4-2w²-2w+w³

now we know one thing that 1+w+w²=0

now what you do multiply both side with 2

so that's equal to 2+2w+2w²=0, 2= -2w-2w²

w³=1

so from beginning

4+2+1=7