2 z + z + 1
z^2 + z + 1
2 1 + z + z
1 + z + z^2
/ ___\ / ___\ | 1 I*\/ 3 | | 1 I*\/ 3 | |x + - + -------|*|x + - - -------| \ 2 2 / \ 2 2 /
(x + 1/2 + i*sqrt(3)/2)*(x + 1/2 - i*sqrt(3)/2)
1.0 + z + z^2
1 + z*(1 + z)