2 x ------ + 2*x*atan(x) 2 1 + x
/ 3 \ | x 2*x | 2*|- --------- + ------ + atan(x)| | 2 2 | | / 2\ 1 + x | \ \1 + x / /
/ / 2 \\ | 2 | 4*x || | x *|-1 + ------|| | 2 | 2|| | 6*x \ 1 + x /| 2*|3 - ------ + ----------------| | 2 2 | \ 1 + x 1 + x / --------------------------------- 2 1 + x