解题方法
1 . 如图,在三棱柱
中,
平面
,
,
,且
,
,
分别为棱
,
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/d148119a-84ee-4315-bd7c-d7524628376c.png?resizew=169)
(1)证明:直线
与
共面;并求其所成角的余弦值;
(2)在棱
上是否存在点
,使得
平面
,若存在,求
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/520828c9d9e777117f6d432babee0816.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/d148119a-84ee-4315-bd7c-d7524628376c.png?resizew=169)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f348ed8a1690d3ed02aa64459ca50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f1158eaa2e338f564eb18de5bef1d25.png)
(2)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e97fcdcfd6183b976a61ef3222c607.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d0492b25f10ae45c39f8e9838519259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/458d492ab8896be57a54ec905d8e2f4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3806ce048077abdada6855ad60969b07.png)
您最近一年使用:0次
2020-02-18更新
|
378次组卷
|
3卷引用:陕西省宝鸡市千阳中学2021届高三下学期第六次适应性训练理科数学试题
2 . 如图所示,已知等腰直角三角形RBC,其中∠RBC=90°,RB=BC=2.点A,D分别是RB,RC的中点,现将△RAD沿着边AD折起到PAD位置,使PA⊥AB,连接PB,PC.
![](https://img.xkw.com/dksih/QBM/2019/4/15/2182859475075072/2183264968081408/STEM/a2a12376ca3e434aa4af12627aff047c.png?resizew=158)
(1)求证:AD∥面PBC;
(2)求二面角A-CD-P的余弦值.
![](https://img.xkw.com/dksih/QBM/2019/4/15/2182859475075072/2183264968081408/STEM/a2a12376ca3e434aa4af12627aff047c.png?resizew=158)
(1)求证:AD∥面PBC;
(2)求二面角A-CD-P的余弦值.
您最近一年使用:0次
3 . 如图,在三棱锥
中,
,
在底面
上的射影为
,
,
于
.
![](https://img.xkw.com/dksih/QBM/2016/3/8/1572526056292352/1572526062632960/STEM/5f01c63d515143c3ac60a0599554b333.png?resizew=237)
(1)求证:平面
平面
;
(2)若
,
,
,求直线
与平面
所成的角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4357d5744046d4d44abb09e1ee35fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee0f630195bcf6c3ca8f4fdeff43b082.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aa30a9ee227af2b387cf6e028c20d7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/2016/3/8/1572526056292352/1572526062632960/STEM/5f01c63d515143c3ac60a0599554b333.png?resizew=237)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a0e5697eca3f5205cb7b343648240bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7502eee6f33e8c940dec63ab6473c52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ddc76d96d6951ebfef3fe63892a1114.png)
您最近一年使用:0次
2016-12-04更新
|
831次组卷
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4卷引用:2016届陕西省西安市一中高三下学期第一次模拟理科数学试卷