x=3, y=ω2+2ω, z=ω+2ω2 then x2+y2+z2=
12
24
36
48
x2+y2+z2= 9+(ω2+2ω)2+(ω+2ω2)2
=9+ω4+4ω2+4ω3+ω2+4ω4+4ω3
=9+4+4+5ω4+5ω2
=9+8−5=12