用分步积分
∫(x^2+1)e^xdx
=∫(x^2+1)de^x
=(x^2+1)e^x-∫e^xd(x^2+1)
=(x^2+1)e^x-∫2xe^xdx
=(x^2+1-2x)e^x+2∫e^xdx
=(x^2+3-2x)e^x+C