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