acos(6*x)
-6 -------------- ___________ / 2 \/ 1 - 36*x
-216*x -------------- 3/2 / 2\ \1 - 36*x /
/ 2 \ | 108*x | -216*|1 + ---------| | 2| \ 1 - 36*x / -------------------- 3/2 / 2\ \1 - 36*x /