8*atan(4*x) ----------- 2 1 + 16*x
32*(1 - 8*x*atan(4*x)) ---------------------- 2 / 2\ \1 + 16*x /
/ 2 \ | 12*x 64*x *atan(4*x)| 256*|-atan(4*x) - --------- + ---------------| | 2 2 | \ 1 + 16*x 1 + 16*x / ---------------------------------------------- 2 / 2\ \1 + 16*x /