2 1 2*x ------ - --------- 2 2 x - 1 / 2 \ \x - 1/
1/(-1.0 + x^2) - 2.0*x^2/(-1.0 + x^2)^2
2 / 2\ 2 / 2\ \-1 + x / - 2*x *\-1 + x / --------------------------- 3 / 2\ \-1 + x /
2 -1 - x ---------- 2 / 2\ \-1 + x /
/ 2\ -\1 + x / ------------- 4 2 1 + x - 2*x
/ 2\ -\1 + x / ------------------ 2 2 (1 + x) *(-1 + x)