名校
解题方法
1 . 如图,在圆锥
中,若轴截面
是正三角形,C为底面圆周上一点,F为线段
上一点,D(不与S重合)为母线上一点,过D作
垂直底面于E,连接
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/1/4a784b01-e920-40f1-82dd-3d86a0610067.png?resizew=153)
(1)求证:平面
平面
;
(2)若
为正三角形,且F为
的中点,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18e5ef91fb27dd684a27ae7f1993cfba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23354ef3b5664149f9c77564d668885f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40cbba955e542f4f53713c208c45cf9a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/1/4a784b01-e920-40f1-82dd-3d86a0610067.png?resizew=153)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de1010b502298fdffba6d90265a199ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbd1c4e883518a7ac5a7517615e47e86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14eec658f69c267a70c1e8f9b744e282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
您最近一年使用:0次
2024-03-07更新
|
792次组卷
|
2卷引用:山东省部分名校2023-2024学年高三下学期2月大联考数学试题
名校
解题方法
2 . 类比于二维平面中的余弦定理,有三维空间中的三面角余弦定理;如图1,由射线
,
,
构成的三面角
,
,
,
,二面角
的大小为
,则
.
、
时,证明以上三面角余弦定理;
(2)如图2,平行六面体
中,平面
平面
,
,
,
①求
的余弦值;
②在直线
上是否存在点
,使
平面
?若存在,求出点
的位置;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa26fadeee2becc192fa53d778445d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac229a5e782559ffb0f271cbfc01c6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef6ab2d197160f40b72fe0abb3fe527d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e14113e0a7ac6b8e1faf51dbcc6dbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17cc100e36303b3566d91e4756594cf2.png)
(2)如图2,平行六面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f81e24376a13d648c2ed0dc73bc710e.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/947c03e48c4be7485f1547817f890c53.png)
②在直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f475878dd1b32b0486cbf7b5ffbedd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee3d1518e197f7f25c341da6b1e3483.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
您最近一年使用:0次
2021-07-10更新
|
3419次组卷
|
11卷引用:山东省多校2023-2024学年高二上学期9月联合测评数学试题
山东省多校2023-2024学年高二上学期9月联合测评数学试题四川省成都市第七中学2020-2021学年高一下学期期末考试数学试题湖南省长沙市雅礼中学等十六校2022届高三下学期第二次联考数学试题(已下线)专题24 立体几何解答题最全归纳总结-3(已下线)专题08 立体几何解答题常考全归类(精讲精练)-2(已下线)第八章立体几何初步章末题型大总结(精讲)(2)-【精讲精练】2022-2023学年高一数学下学期同步精讲精练(人教A版2019必修第二册)湖南省重点高中2023届高三下学期高考模拟数学试题江苏省无锡市市北高级中学2022-2023学年高一下学期期中数学试题(已下线)重难点突破06 立体几何解答题最全归纳总结(九大题型)-3(已下线)重难点12 立体几何必考经典解答题全归类【九大题型】河南省安阳市2024届高三第三次模拟考试数学试题