acos(4*x)
d --(acos(4*x)) dx
-4 -------------- ___________ / 2 \/ 1 - 16*x
-64*x
--------------
3/2
/ 2\
\1 - 16*x /
/ 2 \
| 48*x |
-64*|1 + ---------|
| 2|
\ 1 - 16*x /
-------------------
3/2
/ 2\
\1 - 16*x /