∫ x/[(1+x^2)]^3 dx
=1/2*∫ 1/[(1+x^2)]^3 d(x^2)
=1/2*∫ 1/[(1+x^2)]^3 d(1+x^2)
=1/2*(-1/2)*(1+x^2)^(-2)+C
=(-1/4)*(1+x^2)^(-2)+C
代入数值得,原式=(-1/4)*(1+1)^(-2)-(-1/4)*(1+0)^(-2)
=-1/16+1/4
=3/16