/ ___\ atanh\\/ x /
1 --------------- ___ 2*\/ x *(1 - x)
1 2 - + ------ x -1 + x ---------------- ___ 4*\/ x *(-1 + x)
/ 1 3 1 \ -|--------- + ---- + ------------| | 2 2 2*x*(-1 + x)| \(-1 + x) 8*x / ----------------------------------- ___ \/ x *(-1 + x)