题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-66504.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-78090.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-86235.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-94596.png)
(1)定义横、纵坐标为整数的点为“整点”,在区域
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-78090.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-87610.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-28211.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-94596.png)
(2)在区域
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-78090.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-87610.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-87610.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-94596.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103649-54869.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103649-65008.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103649-69206.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![]() ![]() | 0 | 1 | 2 | 3 |
![]() | ![]() | ![]() | ![]() | ![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103651-19838.png)
解析
(1)依题可得:平面区域U的面积为:π•22=4π,平面区域V的面积为:
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103651-22794.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103651-86807.png)
易知:X的可能取值为0,1,2,3,则X∽B(3,
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103651-86807.png)
(1)依题可知平面区域
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-78090.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103652-12885.png)
平面区域
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-94596.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103652-56788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103649-69206.png)
(2)依题可得:平面区域
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-78090.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103652-24027.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-94596.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103652-73968.png)
在区域
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103647-78090.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-94596.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103653-76852.png)
法一:显然
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103653-98438.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103653-82745.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103653-57322.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![]() ![]() | 0 | 1 | 2 | 3 |
![]() | ![]() | ![]() | ![]() | ![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103654-62539.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103654-38816.png)
法二:
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103654-13253.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103654-76574.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103655-95321.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![]() ![]() | 0 | 1 | 2 | 3 |
![]() | ![]() | ![]() | ![]() | ![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103648-59967.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191027/20191027103651-19838.png)
核心考点
试题【设不等式确定的平面区域为,确定的平面区域为(1)定义横、纵坐标为整数的点为“整点”,在区域内任取个整点,求这些整点中恰有个整点在区域内的概率;(2)在区域内任取】;主要考察你对相互独立事件的概率等知识点的理解。[详细]
举一反三