xe^x^2求导=e^(x²)+x*(e^(x²))'=e^(x²)+xe^(x²)(x²)'=e^(x²)+2x²e^(x²)
(xe^x^2)’=(x*e^x^2)’=x’*e^x^2+x*(e^x^2)’=e^x^2+x(e^x^2)’=e^x^2+x(e^x^2*2x)=e^x^2+2x^2*e^x^2=(1+2x^2)e^x^2
