定義
曲間的劃分(partition)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/9/d67/wZwpmLwUjM4QzM0gzMxMzM1UTM1QDN5MjM5ADMwAjMwUzL4MzL2QzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
定義:曲間 的一個劃分是指一個有限的序列 ,滿足
![達布上和](/img/6/011/wZwpmLxgDNwUTN3QzNxUTN1UTM1QDN5MjM5ADMwAjMwUzL0czLyczLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
達布和
![達布上和](/img/8/778/wZwpmL2MzN5UzM2MzNwIDN0UTMyITNykTO0EDMwAjMwUzLzczL4MzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/c/4a9/wZwpmLyYTN4MDO2ETM0YTN1UTM1QDN5MjM5ADMwAjMwUzLxEzLzczLt92YucmbvRWdo5Cd0FmLxE2LvoDc0RHa.jpg)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
定義1.設 是定義在曲間 上的函式,設 是 的一個劃分,設
![達布上和](/img/9/d99/wZwpmL1ITM0gzM1AzNxUTN1UTM1QDN5MjM5ADMwAjMwUzLwczLyEzLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
記
![達布上和](/img/9/2d1/wZwpmL1UzMxEzN3ITOzYTN1UTM1QDN5MjM5ADMwAjMwUzLykzL3IzLt92YucmbvRWdo5Cd0FmL0E2LvoDc0RHa.jpg)
![達布上和](/img/a/a5d/wZwpmLwAzN0ETNwkjNzYTN1UTM1QDN5MjM5ADMwAjMwUzL5YzL0MzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
![達布上和](/img/2/a33/wZwpmL3AzNyUzN0MDOzYTN1UTM1QDN5MjM5ADMwAjMwUzLzgzLzIzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
稱 為關於劃分P的達布上和與達布下和 。
達布積分
![達布上和](/img/8/778/wZwpmL2MzN5UzM2MzNwIDN0UTMyITNykTO0EDMwAjMwUzLzczL4MzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
定義2.設 是定義在曲間 上的函式,記
![達布上和](/img/5/6ed/wZwpmL2EDOyADMxMDOxUTN1UTM1QDN5MjM5ADMwAjMwUzLzgzLxQzLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
![達布上和](/img/0/1ab/wZwpmL0QTMzkTN0gjMxUTN1UTM1QDN5MjM5ADMwAjMwUzL4IzL0gzLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
![達布上和](/img/d/f35/wZwpmL1ATN0UTO4IDOxUTN1UTM1QDN5MjM5ADMwAjMwUzLygzLxIzLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
![達布上和](/img/8/778/wZwpmL2MzN5UzM2MzNwIDN0UTMyITNykTO0EDMwAjMwUzLzczL4MzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
稱 為 的達布上積分與達布下積分 ,或者,記為
![達布上和](/img/2/b1f/wZwpmL2QTNxAzM0AzNxUTN1UTM1QDN5MjM5ADMwAjMwUzLwczLwAzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
達布可積
![達布上和](/img/8/778/wZwpmL2MzN5UzM2MzNwIDN0UTMyITNykTO0EDMwAjMwUzLzczL4MzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/8/778/wZwpmL2MzN5UzM2MzNwIDN0UTMyITNykTO0EDMwAjMwUzLzczL4MzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
定義3.設 是定義在曲間 上的函式,稱 是達布可積的,若
![達布上和](/img/4/238/wZwpmL0YzN4EzMzgjNzYTN1UTM1QDN5MjM5ADMwAjMwUzL4YzLwYzLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
性質
![達布上和](/img/8/778/wZwpmL2MzN5UzM2MzNwIDN0UTMyITNykTO0EDMwAjMwUzLzczL4MzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
以下總假定 是定義在曲間 上的函式。則達布和、達布積分各具有下列性質 :
1)對於任何給定的劃分,達布上總是大於或等於達布下和。且具有下列不等式成立:
![達布上和](/img/3/08d/wZwpmL1UzN5gTM5UzNzYTN1UTM1QDN5MjM5ADMwAjMwUzL1czL0QzLt92YucmbvRWdo5Cd0FmLxE2LvoDc0RHa.jpg)
2)達布積分滿足下列不等式:
![達布上和](/img/d/989/wZwpmLzATO5ATOzITM0YTN1UTM1QDN5MjM5ADMwAjMwUzLyEzLxAzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/e/383/wZwpmLzQzN5ITN4EDO0kTO0UTMyITNykTO0EDMwAjMwUzLxgzL3AzLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
3)對任意 ,
![達布上和](/img/3/268/wZwpmL1YTN2kTO4IDOxUTN1UTM1QDN5MjM5ADMwAjMwUzLygzLyYzLt92YucmbvRWdo5Cd0FmL0E2LvoDc0RHa.jpg)
![達布上和](/img/9/ce6/wZwpmLyATN5UjM4QTOwADN0UTMyITNykTO0EDMwAjMwUzL0kzL1AzLt92YucmbvRWdo5Cd0FmL0E2LvoDc0RHa.jpg)
![達布上和](/img/e/a8c/wZwpmLxMjN3kDO3QjN0kTO0UTMyITNykTO0EDMwAjMwUzL0YzL3IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
4) 是定義在曲間 上的函式,
![達布上和](/img/9/26d/wZwpmLygDOxUDM1MDOxUTN1UTM1QDN5MjM5ADMwAjMwUzLzgzLyIzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/e/bd3/wZwpmL2UDO4kDM4UzNzYTN1UTM1QDN5MjM5ADMwAjMwUzL1czL1AzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
5)對 ,
![達布上和](/img/3/db2/wZwpmL0czM5MzNxADOzYTN1UTM1QDN5MjM5ADMwAjMwUzLwgzL3gzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/4/74b/wZwpmLwYTMzITNwAzN0MTN1UTM1QDN5MjM5ADMwAjMwUzLwczLwMzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
6)對
![達布上和](/img/a/e3a/wZwpmLyIDNwgjN0MTOzYTN1UTM1QDN5MjM5ADMwAjMwUzLzkzLwMzLt92YucmbvRWdo5Cd0FmL0E2LvoDc0RHa.jpg)
7)
![達布上和](/img/8/94b/wZwpmL3gTOxIzM2QDM0YTN1UTM1QDN5MjM5ADMwAjMwUzL0AzL1gzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/9/565/wZwpmLyIDOwgjM5ETM0YTN1UTM1QDN5MjM5ADMwAjMwUzLxEzLwMzLt92YucmbvRWdo5Cd0FmL0E2LvoDc0RHa.jpg)
是Lipschitz連續的。
例子
![達布上和](/img/2/2e1/wZwpmL2ETN4IDM2gTM2EzM1UTM1QDN5MjM5ADMwAjMwUzL4EzL2YzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
![達布上和](/img/b/50b/wZwpmLxcTM4IDO0QTM2EzM1UTM1QDN5MjM5ADMwAjMwUzL0EzL1QzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
![達布上和](/img/9/d6c/wZwpmLwYTMzMTO5MTO0AzM1UTM1QDN5MjM5ADMwAjMwUzLzkzL1YzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/b/50b/wZwpmLxcTM4IDO0QTM2EzM1UTM1QDN5MjM5ADMwAjMwUzL0EzL1QzLt92YucmbvRWdo5Cd0FmLwE2LvoDc0RHa.jpg)
![達布上和](/img/a/e3f/wZwpmL1AzN1kDO3ATMwEDN0UTMyITNykTO0EDMwAjMwUzLwEzL4UzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
設是定義在曲間上的函式,設劃分是將平均分割成等分。則有
![達布上和](/img/9/d6f/wZwpmL1cDOwIDO3YDOzYTN1UTM1QDN5MjM5ADMwAjMwUzL2gzL1IzLt92YucmbvRWdo5Cd0FmLzE2LvoDc0RHa.jpg)
![達布上和](/img/0/831/wZwpmL1UzM4IzM3gjMxUTN1UTM1QDN5MjM5ADMwAjMwUzL4IzL3czLt92YucmbvRWdo5Cd0FmLyE2LvoDc0RHa.jpg)
因此,有
![達布上和](/img/0/f11/wZwpmLyIzMyIjNzMDOzYTN1UTM1QDN5MjM5ADMwAjMwUzLzgzLzMzLt92YucmbvRWdo5Cd0FmLxE2LvoDc0RHa.jpg)