/ 3\ \x + x /*atan(x)
(x + x^3)*atan(x)
3 x + x / 2\ ------ + \1 + 3*x /*atan(x) 2 1 + x
/ 2 2 \ |1 + 3*x x | 2*|-------- - ------ + 3*x*atan(x)| | 2 2 | \ 1 + x 1 + x /
/ / 2 \ \ | | 4*x | | | x*|-1 + ------| | | | 2| / 2\| | 9*x \ 1 + x / 3*x*\1 + 3*x /| 2*|3*atan(x) + ------ + --------------- - --------------| | 2 2 2 | | 1 + x 1 + x / 2\ | \ \1 + x / /