将如图的直角梯形
(图中数字表示对应线段的长度)沿直线CD折成直二面角,连结部分线段后围成一个空间几何体,如图所示.
(I)证明:直线
平面
;
(II)求面
与面
所成角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
(I)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9b3b18b7f7e08f195bcdf3acfffff3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa3254460ecbacecb3e57c5dce227f4.png)
(II)求面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3c4554df2d60bde7377c63aad1f0e7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2012/2/7/1570721570758656/1570721576206336/STEM/9de439ea286f4428aede3023e584cea8.png?resizew=291)
12-13高三上·山东泰安·期末 查看更多[1]
(已下线)2012届山东省泰安市高三上学期期末考试理科数学
更新时间:2016-12-01 14:24:08
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相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,在四棱锥
中,底面
为平行四边形,点
在面
内的射影为
,
,点
到平面
的距离为
,且直线
与
垂直.
![](https://img.xkw.com/dksih/QBM/2020/4/30/2452895612411904/2454026483580928/STEM/77545f28098d4553b378a3aed770dd89.png?resizew=210)
(Ⅰ)在棱
找点
,使直线
与平面
平行,并说明理由;
(Ⅱ)在(Ⅰ)的条件下,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e7b6d04f024ca05cdfacc8ce9137c15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/2020/4/30/2452895612411904/2454026483580928/STEM/77545f28098d4553b378a3aed770dd89.png?resizew=210)
(Ⅰ)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(Ⅱ)在(Ⅰ)的条件下,求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faac332bffea75e7b587596c3809278f.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在四棱锥
中,
底面
,
,
,
,
为棱
的中点.
(
)求证:
.
(
)求证:平面
平面
.
(
)试判断
与平面
是否平行?并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1430a3a1f94e6eece84be87811bffb74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64f1161e0345b3646c71365430dccbb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7dac702fe64edf1bc265da4b98cf2a0.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
![](https://img.xkw.com/dksih/QBM/2018/3/29/1912173837615104/1913366067560448/STEM/ec509c2c356e4abb827327979c766792.png?resizew=170)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】在如图所示的直三棱柱
中,
分别是线段
上的动点.
平面
,求证:
;
(2)若
为正三角形,E是
的中点,求二面角
余弦值的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2f90a45697e150b04ab6a2d11420bd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ddef39ef9ed3da136c4ed8b5d28b73e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063510e3c1fb6a7ccc3b8e3e3c7d660e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf498d061e4e8f4856717e8adb549c5c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e384e0ffc3d599303b77ee2a12221e.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】四棱锥P-ABCD中,PA⊥平面ABCD,四边形ABCD为菱形,∠ADC=60°,PA=AD=2,E为AD的中点.
![](https://img.xkw.com/dksih/QBM/2020/8/28/2537770432323584/2543246176026624/STEM/4e854418-8754-4227-a1f2-c2040042fde9.png?resizew=247)
(1)求证:平面PCE⊥平面PAD;
(2)求PC与平面PAD所成的角的正切值;
(3)求二面角A-PD-C的正弦值.
![](https://img.xkw.com/dksih/QBM/2020/8/28/2537770432323584/2543246176026624/STEM/4e854418-8754-4227-a1f2-c2040042fde9.png?resizew=247)
(1)求证:平面PCE⊥平面PAD;
(2)求PC与平面PAD所成的角的正切值;
(3)求二面角A-PD-C的正弦值.
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