先用凑微分∫(x^3)e^(x^2)dx=(1/2)∫(x^2)e^(x^2)dx^2再用分部积分法=(1/2)∫(x^2)de^(x^2)=(1/2)(x^2)e^(x^2) - (1/2)∫e^(x^2)dx^2=(1/2)(x^2)e^(x^2) - (1/2)e^(x^2)=(1/2)(e^(x^2))(x^2-1)
