/ ___\ / ___\ | 1 I*\/ 3 | | 1 I*\/ 3 | 1*(x + 2/3)*|x + - - + -------|*|x + - - - -------| \ 3 3 / \ 3 3 /
((1*(x + 2/3))*(x - (1/3 + i*sqrt(3)/3)))*(x - (1/3 - i*sqrt(3)/3))
3 8 + 27*z --------- 27
(8 + 27*z^3)/27
/ 2\ (2 + 3*z)*\4 - 6*z + 9*z / -------------------------- 27
(2 + 3*z)*(4 - 6*z + 9*z^2)/27