在三棱柱
中,平面
平面
,
为正三角形,D,E分别为
和
的中点.
平面
;
(2)
,
,再从条件①,条件②,条件③中选择一个作为已知,使三棱柱唯一确定,求DE与平面
所成角的正弦值.
条件①:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a19338598965bb3856cdd0236bbf694.png)
条件②:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff7cff6f0357c77698b5f915ce1833f4.png)
条件③:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a27bad0636a087e38bb1d253d66a231d.png)
注:如果选择的条件不符合要求,第(2)问得0分;如果选择多个符合要求的条件分别解答,按第一个解答计分.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85a2e10a5aebe40a9018d5ee3ade7af8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063510e3c1fb6a7ccc3b8e3e3c7d660e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88fc97db5b1b21dab86929b15690f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b94e97d085cea077cb82a0b7d2f523e.png)
条件①:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a19338598965bb3856cdd0236bbf694.png)
条件②:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff7cff6f0357c77698b5f915ce1833f4.png)
条件③:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a27bad0636a087e38bb1d253d66a231d.png)
注:如果选择的条件不符合要求,第(2)问得0分;如果选择多个符合要求的条件分别解答,按第一个解答计分.
更新时间:2024-02-27 10:31:40
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】如图,在多面体
中,四边形
与
都是直角梯形,且
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/3/23/2683973636276224/2687641932603392/STEM/8fcf6266-e712-447d-afc4-c1595a416fca.png)
(1)证明:
平面
;
(2)若平面
平面
,且
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a3b8602719b3d371bc9ec6c441bb9f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b0e70209599e5dbcb5f2dd77fb66cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63434b358984edd9c2514dfefff7f2b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ed4e3d2f560f8be7c2743d85492e5b6.png)
![](https://img.xkw.com/dksih/QBM/2021/3/23/2683973636276224/2687641932603392/STEM/8fcf6266-e712-447d-afc4-c1595a416fca.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d27ff0b39832f094ec51e28721d739.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa3254460ecbacecb3e57c5dce227f4.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c674dc5024374f53920947c4cf4baf11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/133ac212fbb42063ccf66f61c35d4ef6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1d76403bac26df50d934d93586f8a11.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
解题方法
【推荐2】如图,在四棱锥
中,底面
为正方形,
平面
,
,
为
中点,
为
中点,
为线段
上动点.
为
中点,求证:
平面
;
(2)证明:
平面
.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9a4950a6e4202efd609507964af238b.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/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c19129982fd8389238b303e091bd94c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】在四棱柱
中,底面ABCD为正方形,侧面
为菱形,且平面
平面ABCD.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/13/f4906ca3-07b5-4fae-876b-4f32dad3abd6.png?resizew=227)
(1)证明:
;
(2)设点P在棱
上运动,若
,且
,记直线
与平面PBC所成的角为
,当
时,求
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebb05874eb3353d754af24c9974273e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd14966183389b10618cbe33fd777407.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/13/f4906ca3-07b5-4fae-876b-4f32dad3abd6.png?resizew=227)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/774edd1767cdd8de9da66657c30e62eb.png)
(2)设点P在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f436b2f2edf1a47f80a4c439d6938646.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df5960eef4ba8aa8fbb8baf61a7a1f63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0ff310aabd2282b539537ebed3f788.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图,三棱锥
中,
平面
,
,
,
,
为
的中点,过点
作
平行于
,且
.连接
,
,
.
(Ⅰ)证明:
平面
;
(Ⅱ) 求直线
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc532cfe64300cb3da9e04a307c957a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e486a1aad96167ff62f6fb5136e0bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f44447c0867e6ba50c960f7b5bee7036.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf702adb116c1e46569eb7050d029f49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/350e954f629c1901a5cec03558319e46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f6927cc2a930203ac34366383e76ef.png)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14ddcfd8985d6ef923063a301e2bc5ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(Ⅱ) 求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64484f96568410926e0c50898eba6e32.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/0b5eae4e-c54d-4614-ac99-1f72b88e6750.png?resizew=178)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】在长方体
中,
,点
分别是直线
,直线
的中点.
![](https://img.xkw.com/dksih/QBM/2021/12/6/2866479423389696/2871472414851072/STEM/4e17bdba9c4d405fb6e5b687e8269ee2.png?resizew=256)
(1)求证:
平面
;
(2)求点F到平面
的距离;
(3)求直线
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891e69882a41b77a2a64fb6dd1b8af01.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://img.xkw.com/dksih/QBM/2021/12/6/2866479423389696/2871472414851072/STEM/4e17bdba9c4d405fb6e5b687e8269ee2.png?resizew=256)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7175df06e33cad4e6bbc3f2f6b0a2986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fefd8229243bcbee5ac197740e6c66ab.png)
(2)求点F到平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fefd8229243bcbee5ac197740e6c66ab.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fefd8229243bcbee5ac197740e6c66ab.png)
您最近一年使用:0次