题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050312-24551.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050312-93369.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050312-87217.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050313-82126.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050313-97717.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050313-54289.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050313-79157.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050313-30769.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050314-27413.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050314-46947.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050314-78928.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050314-17113.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050315-44838.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050315-44309.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050315-37249.png)
解析
试题分析:三棱锥体积为
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050315-72282.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050315-17381.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050314-17113.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050316-57976.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050316-67705.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050316-54728.png)
点评:本题将不等式恒成立求参数范围转化为求函数最值问题,进而借助于均值不等式求得最值,本题有一定的综合性和难度
核心考点
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050258-92813.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050258-46660.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050258-51869.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050259-21892.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050259-25582.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050259-33629.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050259-60874.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050258-51869.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050259-39309.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050300-79881.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050300-60576.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050300-54455.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050300-54581.png)
(1)证明:
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050301-23373.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050301-63218.png)
(2)求二面角
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050301-62868.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050247-32264.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050247-64714.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050247-88829.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050247-72708.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050248-84303.png)
①
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050248-42660.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050248-50654.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050248-59189.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050249-93364.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050222-42312.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050222-53732.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050222-65756.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050222-87548.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050222-17646.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050223-33630.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050223-63222.png)
(1)证明:
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050223-40231.png)
(2)求二面角
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050223-69368.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050215-15829.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050215-33248.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-61021.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-92054.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-46284.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-32709.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-32709.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-92054.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-46284.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-39256.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050217-52875.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050217-52875.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050216-39256.png)
A.4 | B.3 | C.2 | D.1 |
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050206-97195.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050206-24943.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022050206-35024.png)
(Ⅰ)求证:CF∥面ABE;
(Ⅱ)求证:面ABE ⊥平面BDE;
(Ⅲ)求该几何体ABECD的体积。
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