/ ___\ / ___\ | 1 I*\/ 3 | | 1 I*\/ 3 | (a + 1)*a*|a + - - + -------|*|a + - - - -------| \ 2 2 / \ 2 2 /
(((a + 1)*a)*(a - 1/2 + i*sqrt(3)/2))*(a - 1/2 - i*sqrt(3)/2)
4 / 2 \ a *(1 + a)*\1 + a - a/
a^4*(1 + a)*(1 + a^2 - a)
4 / 3\ a *\1 + a /
a^4*(1 + a^3)