acot(3*x)*2 ----------- sin(2)
(acot(3*x)*2)/sin(2)
-6 ----------------- / 2\ \1 + 9*x /*sin(2)
108*x ------------------ 2 / 2\ \1 + 9*x / *sin(2)
/ 2 \ | 36*x | -108*|-1 + --------| | 2| \ 1 + 9*x / -------------------- 2 / 2\ \1 + 9*x / *sin(2)