∫(arctanx)/(x^2(x^2+1))dx=∫(arctanx)/x^2dx-∫(arctanx)/(x^2+1)dx=∫(arctanx)d(1/x)-∫(arctanx)darctanx=arctanx/x-∫1/xdarctanx-1/2(arctanx)^2=arctanx/x-1/2(arctanx)^2-∫1/[x(x^2+1)]dx=arctanx/x-1/2(...