Ответ (Неопределённый)
[src] /
| ___ / ___\ ___ / ___\ ___ / 2 ___\ ___ / 2 ___\
| / 2\ / 2\ \/ 2 *atan\1 + x*\/ 2 / \/ 2 *atan\-1 + x*\/ 2 / \/ 2 *log\1 + x - x*\/ 2 / \/ 2 *log\1 + x + x*\/ 2 /
| atan\x / dx = C + x*atan\x / - ----------------------- - ------------------------ - --------------------------- + ---------------------------
| 2 2 4 4
/
$$x\,\arctan x^2-2\,\left(-{{\log \left(x^2+\sqrt{2}\,x+1\right)
}\over{2^{{{5}\over{2}}}}}+{{\log \left(x^2-\sqrt{2}\,x+1\right)
}\over{2^{{{5}\over{2}}}}}+{{\arctan \left({{2\,x+\sqrt{2}}\over{
\sqrt{2}}}\right)}\over{2^{{{3}\over{2}}}}}+{{\arctan \left({{2\,x-
\sqrt{2}}\over{\sqrt{2}}}\right)}\over{2^{{{3}\over{2}}}}}\right)$$