4 3 2 x + x + x - x - 2 -------------------- 3 x + x - 2
2 3 4 -2 + x + x + x - x --------------------- 3 -2 + x + x
(-2.0 + x^2 + x^3 + x^4 - x)/(-2.0 + x + x^3)
-2 + x*(-1 + x*(1 + x*(1 + x))) ------------------------------- / 2\ -2 + x*\1 + x /
1 + x