答：y=x³lnxy'(x)=(x³)' lnx+(x³)(lnx)'y'(x)=3x²lnx+x²y''(x)=(3x²)'lnx+3x²(lnx)'+(x²)'y''(x)=6xlnx+3x²(1/x)+2xy''(x)=6xlnx+3x+2xy''(x)=6xlnx+5x
y'=3x^2 ln x+x^3*1/x=3x^2 ln x+x^2y''=6xlnx+3x+2x=6xlnx+5x
