atan(4 - 3*x)
-3 -------------- 2 1 + (4 - 3*x)
18*(-4 + 3*x) ----------------- 2 / 2\ \1 + (4 - 3*x) /
/ 2 \ | 4*(-4 + 3*x) | 54*|1 - --------------| | 2| \ 1 + (4 - 3*x) / ----------------------- 2 / 2\ \1 + (4 - 3*x) /