∫x^2(lnx+1)dx
=1/3 *∫(lnx+1)d(x^3)
=1/3 * x^3 *(lnx+1) -∫1/3 *x^3 d(lnx+1)
=1/3 *x^3 *(lnx+1) -∫1/3 *x^2 dx
=1/3 *x^3 *(lnx+1) - 1/9 *x^3+C,C为常数