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