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