名校
解题方法
1 . 如图
,直角梯形
,
,将
沿
折起来,使平面
平面
.如图
,设
为
的中点,
,
的中点为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/5724be25-5478-45c0-87f3-a77dc61d8262.png?resizew=418)
(
)求证:
平面
.
(
)求平面
与平面
所成锐二面角的余弦值.
(
)在线段
上是否存在点
,使得
平面
,若存在确定点
的位置,若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a717c411ecb25464d817d7c2e807164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb4cb0b82547733eef4343354bb7c791.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/5724be25-5478-45c0-87f3-a77dc61d8262.png?resizew=418)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ce03b310edce42191f9fa75a1c909ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df82499e4eaac32e09290faf3d2a166b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b78172568aac9805d2ea2d5f742bf80c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cd0b0bda79a950fe6f44fc6d62740f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
您最近一年使用:0次
2 . 我国古代数学名著《九章算术》中记载的“刍甍”是底面为矩形,顶部只有一条棱的五面体.如图,五面体
是一个“刍甍”,四边形
为矩形,
与
都是正三角形,
,
.
![](https://img.xkw.com/dksih/QBM/2018/12/9/2093247311503360/2093686354321408/STEM/4eec7dd95df640599946526bd828a835.png?resizew=317)
求证:
面
;
求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1019c0405370c673e37b46c066eba839.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c85022048334bb883119115330b45a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae027044287787834a7f69aef58deef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76d527d4795ece4a5756d1cf8dba31e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abcdcc84bdbd118d07b19ac61611e86.png)
![](https://img.xkw.com/dksih/QBM/2018/12/9/2093247311503360/2093686354321408/STEM/4eec7dd95df640599946526bd828a835.png?resizew=317)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aab1cf5f4e0b36edf3b9a064dc75828b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/073a88b42836fb88433679932b48ad03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09446528b12dd384c6828e1ef1c70e90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8120f2eeb724c756b5f84a14c6df527.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c6d456e2adab93eabc931b3227bb79f.png)
您最近一年使用:0次
2018-12-10更新
|
356次组卷
|
3卷引用:2022年浙江省温州市摇篮杯高一数学竞赛试题