y=x^3lnx,
y'=3x^2lnx+x^3*(1/x)=3x^2lnx+x^2=x^2(3lnx+1),
f'(e)=e^2(3lne+1)=4e^2,
f(e)=e^3lne=e^3,
y-e^3=4e^2(x-e),
y=4e^2x-3e^3
y=x^3lnx,
y'=3x^2lnx+x^3*(1/x)=3x^2lnx+x^2=x^2(3lnx+1),
f'(e)=e^2(3lne+1)=4e^2,
f(e)=e^3lne=e^3,
y-e^3=4e^2(x-e),
y=4e^2x-3e^3