請教下點做 ∫2 x^2 lnx dx ？
回答 (1)
2010-06-02 5:09 pm
✔ 最佳答案
∫2x^2 lnx dx= 2/3 ∫ lnx d(x^3) (d(x^3) = 3x^2dx)
= (2/3) x^3lnx - (2/3) ∫ x^3 d(lnx)
= (2/3) x^3lnx - (2/3) ∫ x^3(1/x) dx
= (2/3) x^3lnx - (2/3) ∫x^2 dx
= (2/3) x^3lnx - (2/9) x^3 + C
where C is a constant
參考: Prof. Physics
收錄日期: 2021-04-19 22:25:41
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