名校
1 . 如图,在多面体
中,底面
为矩形,侧面
为梯形,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/31/f43f42a5-4cb4-4a9c-a8da-6ebcadb35367.png?resizew=179)
(1)求证:
;
(2)求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b15cd53fe7b73365723ce4789bb259d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8225b3e02f5a9f1fd5a09ada650cb78.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/31/f43f42a5-4cb4-4a9c-a8da-6ebcadb35367.png?resizew=179)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ccd5c41c921836b50f8e18abfdc5df3.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9d32e76582bf550593fdef53e081225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
您最近一年使用:0次
2019-04-18更新
|
4940次组卷
|
6卷引用:江苏省淮安市盱眙县马坝高级中学2019-2020学年高三上学期期中数学(理)试题
2 . 如图,三棱锥
中,
平面
,
,
,
是
的中点,
是
的中点,点
在
上,
.
![](https://img.xkw.com/dksih/QBM/2017/2/16/1625395186098176/1635395675070464/STEM/5a7ebc730fc54d89b51a38bd4820cc6e.png?resizew=178)
(1)证明:
平面
;
(2)若
,求二面角
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/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bae7599ad243c12d94325ad917f0a44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51627b773b078f4b3651e4459e547da6.png)
![](https://img.xkw.com/dksih/QBM/2017/2/16/1625395186098176/1635395675070464/STEM/5a7ebc730fc54d89b51a38bd4820cc6e.png?resizew=178)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81ca12f11f39405a6a49042c5e294862.png)
您最近一年使用:0次
2017-03-02更新
|
2994次组卷
|
2卷引用:湖南省长沙市明德中学2019-2020学年高二上学期期中数学试题