名校
解题方法
1 . 我国古代数学名著《九章算术》中记载,斜解立方为“堑堵”,即底面是直角三角形的直三棱柱(直三棱柱为侧棱垂直于底面的三棱柱).如图,棱柱
为一个“堑堵”,底面
的三边中的最长边与最短边分别为
,
,且
,
,点
在棱
上,且
,则当
的面积取最小值时,异面直线
与
所成的角的余弦值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ab4629fbb62d88ec595376f3380e543.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0df17464b58614dec9b7b173a540eee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31090d5a79b5de4511809aa4773d02c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ad3a1ea6790177130e16c2124984087.png)
![](https://img.xkw.com/dksih/QBM/2020/7/22/2511303048527872/2511948913524736/STEM/43dd0ed7-dd83-49b6-a28d-a8f2a7125313.png)
您最近一年使用:0次
2020-07-23更新
|
1084次组卷
|
4卷引用:浙江省金华市东阳中学2020-2021学年高二上学期10月段考数学试题
浙江省金华市东阳中学2020-2021学年高二上学期10月段考数学试题山东省2020届高考压轴模拟考试数学试题(已下线)2021届高三数学新高考“8+4+4”小题狂练(5)(已下线)专题5 综合闯关(提升版)
名校
解题方法
2 . 已知两矩形
与
所在的平面互相垂直,
,若将
沿直线
翻折,使得点
落在边
上(即点
),则当
取最小值时,四面体
的外接球的半径是__________ .
![](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/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab17635a999236e8d2e35017a208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90eec53d96ce7808ecc50762e0da5ac0.png)
![](https://img.xkw.com/dksih/QBM/2020/3/31/2431484469321728/2431567907692544/STEM/3977e46964e74fe0ab57eb7f315fcfc0.png?resizew=254)
您最近一年使用:0次
3 . 在正方体
中(如图),已知点
在直线
上运动,则下列四个命题:
①三棱锥
的体积不变;
②直线
与平面
所成的角的大小不变;
③二面角
的大小不变;
④
是平面
上到点
和
距离相等的点,则
点的轨迹是直线![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
其中真命题的编号是__________ .(写出所有真命题的编号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
①三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ad99ef5e70de37345c708b758d545f.png)
②直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7977ab975efa6411cc17de39be70d9.png)
③二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67094912ebf6dd7b27b835af55df4826.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
其中真命题的编号是
您最近一年使用:0次
2017-02-23更新
|
1089次组卷
|
8卷引用:2016-2017学年浙江省名校协作体高二下学期考试数学试卷
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