x ------ 3 x - 1
x/(x^3 - 1)
1/(3*(-1 + x)) - (-1 + x)/(3*(1 + x + x^2))
1 -1 + x ---------- - -------------- 3*(-1 + x) / 2\ 3*\1 + x + x /
x/(-1.0 + x^3)
x --------------------- / 2\ (-1 + x)*\1 + x + x /
x/((-1 + x)*(1 + x + x^2))