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