2 2*t - t + 1 ------------- 2 2 (t + 1) + t
(1.0 - t + 2.0*t^2)/(t^2 + (1.0 + t)^2)
2 1 - t + 2*t -------------- 2 1 + 2*t + 2*t
1 + t*(-1 + 2*t) ---------------- 2 2 t + (1 + t)
2 1 - t + 2*t -------------- 2 1 + 2*t + 2*t
3*t 1 - -------------- 2 1 + 2*t + 2*t