另外問一下
∫x*e^-2x dx 跟 ∫x*e^-x^2 dx
有什麼不一樣呢??他的e那個部分怎麼積分
我們老師寫的怎麼不同數字積出來會一樣呢??
老師是寫
∫x*e^-2x dx= X*-2*e^-2x
∫x*e^-x^2 dx = -2*e^-2x
我想請問這2個是怎麼積出來的
跟e是怎麼積的可以說詳細一點嗎??謝謝作者: himitsuaile 時間: 07-6-29 03:49
First of all, by integration by parts,
It takes positive value instead but not negative one.
∫x*e^-2x dx 跟 ∫x*e^-x^2 dx
有什麼不一樣呢?? <<<
and
他的e那個部分怎麼積分 <<<
To integrate this kind of integrand, we make use of natural logarithm,
a log. with base e as you typed.
illustration:
[As much to say, works of your teacher went wrong]/[you typed an ambiguous/wrong expression of the variables]. You can copy these equations to ask your teacher for inquiry.
