High Numbers | 【Re-integration】Line Area Score 880 Examples

拓展：

1、简单闭曲线

 2、The translational reintegration and the centroid formula speed up the problem solving

 3、Multiply two definite integrals（See Raising the first one）

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一、880基础题

Line area scores determine parity：（个人用）

1、First, determine whether the integration area is about an axis/A plane is symmetrical

2、Determine the symmetry of the integral function

3、Combine integral calculus,判断奇偶性

积分区域关于yoz平面对称,又因 被积函数 关于x为偶函数 为2倍

积分区域关于xoz平面对称,又因 被积函数 关于y为偶函数 为2倍

 find cross section The resulting intersection radius ：高中知识！

这都能忘？立即推——

 因为xyzAll three axes have absolute values, so this is onexyz轴对称的图形,Just draw that one at the first hexagram limitx+y+z＝1的三角形that side came out,All other hexagram limits are symmetrical.

拓展一下：“Formula for calculating the area of ​​an equilateral triangle：S=√3 / 4a².The side length of an equilateral triangle is a.

空间曲线（直线）积分：Generally converted to parametric equations

Type II Stokes available

 三条！！！！！！！！！！！！！！

 

 

 Spatial Curve Parametric Equation：Start by substituting a variable into an equation,Write the parametric equations for the other two variables

 

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二、880提高题

 注：这里的ds Not Arc Micro 而是向量{dx,dy,dz}