2*x + acos(3*x)
3 2 - ------------- __________ / 2 \/ 1 - 9*x
-27*x ------------- 3/2 / 2\ \1 - 9*x /
/ 2 \ | 27*x | -27*|1 + --------| | 2| \ 1 - 9*x / ------------------ 3/2 / 2\ \1 - 9*x /