Integation by Parts

∫x^2 Inx dx
= ∫(x^2)( Inx) dx
= ∫Inx d (x^3)/3
= Inx (x^3)/3 - ∫(x^3)/3 d(Inx)
= Inx (x^3)/3 - ∫(x^3)/3*(1/x) dx
= Inx (x^3)/3 - ∫(x^2)/3 dx
= Inx (x^3)/3 - (x^3)/9 + C ,where C is a constant

∫x^2 Inx dx
=1/3∫ Inx dx^3
= 1/3 (Inx) x^3-1/3∫ x^3 (1/x) dx
=1/3 (Inx) x^3-1/3∫ x^2 dx
=1/3 (Inx) x^3-1/9* x^3

2007-01-04 04:21:26 補充：
我用software做完結果一樣﹐應該冇錯