∵xf′（x）+2f（x）=lnxx，∴x2f′（x）+2xf（x）=lnx∴[x2f（x）]′=lnx，∴x2f（x）=xlnx-x+c，将x=e代入可得：e2f（e）=elne-e+c，∵f（e）=12e，∴c=e2∴x2f（x）=xlnx-x+e2，∴f（x）=2xlnx−2x+e2x2∴f′（x...