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