Evaluate ∫01arctan(x)1+x2dx\int_0^1 \frac{\arctan(x)}{1+x^2} dx∫011+x2arctan(x)dx.
π232\frac{\pi^2}{32}32π2
π8\frac{\pi}{8}8π
π216\frac{\pi^2}{16}16π2
12\frac{1}{2}21