Don't know the steps in finding this derivative.
But the derivative is
The answer is:
/ 2 \ atan(x) |/atan(x) log(x)\ atan(x) 2 2*x*log(x)| x *||------- + ------| - ------- + ---------- - ----------| || x 2| 2 / 2\ 2 | |\ 1 + x / x x*\1 + x / / 2\ | \ \1 + x / /
/ 3 2 \ atan(x) |/atan(x) log(x)\ 6 3 /atan(x) log(x)\ /atan(x) 2 2*x*log(x)\ 2*log(x) 2*atan(x) 8*x *log(x)| x *||------- + ------| - --------- - ----------- - 3*|------- + ------|*|------- - ---------- + ----------| - --------- + --------- + -----------| || x 2| 2 2 / 2\ | x 2| | 2 / 2\ 2 | 2 3 3 | |\ 1 + x / / 2\ x *\1 + x / \ 1 + x / | x x*\1 + x / / 2\ | / 2\ x / 2\ | \ \1 + x / \ \1 + x / / \1 + x / \1 + x / /