acos(1 - x) ----------- ___ \/ 2
acos(1 - x)/sqrt(2)
/ ___\ |\/ 2 | |-----| \ 2 / ----------------- ______________ / 2 \/ 1 - (1 - x)
___ \/ 2 *(-1 + x) ------------------- 3/2 / 2\ 2*\1 - (1 - x) /
/ 2 \ ___ | 3*(-1 + x) | -\/ 2 *|-1 + -------------| | 2| \ -1 + (1 - x) / ---------------------------- 3/2 / 2\ 2*\1 - (1 - x) /