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