题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041133-88564.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041133-30507.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-95323.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041133-88564.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-89319.png)
(1)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-61112.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
(2)求平面
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-98619.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-26801.png)
解析
试题分析:(1)证明法一可建立空间直角坐标系利用
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041135-65504.png)
证明法二:要证
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-61112.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
(2)先求平面PCD的法向量,再利用向量求二面角的公式
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041135-41150.png)
试题解析:
解:如图,以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041135-15752.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041135-41997.png)
可得
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041136-90909.png)
(1)证明法一:因为
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041136-11798.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041136-30249.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041136-74586.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041136-83726.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-37777.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-47136.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-39572.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-47136.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-61112.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
证明法二:因为
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-95323.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041133-88564.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-81276.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041133-88564.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041138-23191.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041138-91231.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041138-56671.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041136-83726.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041138-72284.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-47136.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-39572.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041137-47136.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-61112.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
(2)由(1)知平面
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041138-73613.png)
设平面
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-98619.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041139-42564.png)
又
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041139-22069.png)
且
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041139-50682.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041139-41845.png)
所以平面
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041139-12561.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041140-39247.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041135-41150.png)
所以平面
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-97494.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-98619.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041134-26801.png)
核心考点
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-58891.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-59088.jpg)
(1)求直线
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-73520.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-32281.png)
(2)在线段
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-86268.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-18898.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-15158.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041119-79646.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041107-96735.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041107-90767.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041107-30949.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041107-60665.jpg)
(1)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041107-19365.png)
(2)已知
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041107-15666.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041108-78343.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041108-25712.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041108-84435.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041056-73911.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041056-81325.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041057-82049.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041057-74837.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041057-40402.png)
A.![]() | B.![]() | C.![]() | D.![]() |
A.AC | B.BD | C.A1D | D.A1D1 |
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041040-32763.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041041-86851.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041041-32737.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041041-86851.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041041-67116.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041041-25817.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041042-73390.jpg)
求证:
(1)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041042-37180.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041042-45377.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191022/20191022041042-82877.png)
最新试题
- 1读“某山区交通线与居民点分布图”,回答下列问题。(1)请简要描述图示地区的地形特征。(2分) (2)在AB间修建一条公路
- 2我国开始组建“三位一体”的战略核力量是在 年 [ ]A.1964 B.196
- 3西湖美景名扬天下,观赏西湖的最佳位置是 ( )A.较高的亭台楼阁之上B.低临水面C.适当距离仰视D.适当距离远
- 4已知定义在R上的可导函数f(x)的导函数为f′(x),满足f′(x)<f(x),且f(x+2)为偶函数,f(4)=1,则
- 5化简3x+2(x-3y)的结果是______.
- 6我国工业的分布从整体上看不正确的是[ ]A.沿海分布B.沿江河分布C.沿铁路线分布D.沿国界线分布
- 723. Lucy is going to have difficulty finding a good job ____
- 8下列各组实验中,溶液的酸碱度没有明显变化的是( )A.向氢氧化钠溶液中滴加硫酸铜溶液B.向食盐水中加入稀盐酸C.向氯化
- 9阅读下面这首唐诗,然后回答问题(共10分):楚江怀古① 唐•马戴露气寒光集,微阳下楚丘。猿啼洞庭树,人在木兰
- 10The coats are 200 dollars each, but______we offer a discount
热门考点
- 1滚轴溜冰运动是青少年喜爱的一项活动。如图14所示,一滚轴溜冰运动员(可视为质点)质量m=30kg,他在左侧平台上滑行一段
- 2根据短文内容,从短文后的七个选项中选出能填入空白处的最佳选项.选项中有两项为多余选项.Without plants, p
- 3数列中,,且,(n∈N*),求通项公式.
- 4下图所示的电路中,电源电压恒定为4.5V,电流表示数为0.5A,电压表V1的示数为3V。当把滑动变阻器的滑片移到最右端时
- 5已知点,的坐标分别是,.直线,相交于点,且它们的斜率之积为.(1)求点的轨迹的方程;(2)若过点的两直线和与轨迹都只有一
- 6There are many new bikes ____ for you in the shop. I think y
- 7已知等差数列{an}的前n项和为sn=pm2-2n+q(p,q∈R),n∈N*(I)求q的值;(Ⅱ)若a3=8,数列{b
- 8国有经济在国民经济中发挥着主导作用,主要表现在[ ]①控制着国民经济的命脉②控制着国民经济的发展方向③控制着经济
- 9读下图和资料,完成下列要求。资料:山东省寿光市总面积2180平方千米,人口104万。20世纪80年代以来,寿光市采用了冬
- 10CaC2和ZnC2,Al4C3,Mg2C3,Li2C2等都同属离子型碳化物。请通过对CaC2制C2H2的反应进行思考,从