1 . 《几何原本》是古希腊数学家欧几里得得所著的一部数学著作,在《几何原本》第六卷给出了内角平分线定理,其内容为:在一个三角形中,三角形一个内角的角平分线内分对边所成的两条线段,与这个角的两邻边对应成比例.例如,在
中(图1),
为
的平分线,则有
.
(2)如图2,已知
的重心为
,内心为
,若
的连线
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/608bf0cfbbe809837adec2755fcd2901.png)
(2)如图2,已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e105760638b22b26ff8bec4354255e4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57b8fc74eea80b1ccf11d16ad7b3178a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/981b01ddc1aa5fcf155ad41307d22b17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a94a70686cb9c91ec9705bed47dc663.png)
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解题方法
2 . 如图,在四棱柱
中,底面是边长为1的正方形,侧棱
平面
是
的中点.
(1)求证:
平面
;
(2)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44075378f40f89fb81721a7c5e2a1678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/6/6e8396e8-749f-46e5-a52c-fb5e3673073a.png?resizew=131)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f11f1840eb8b17e7b07c3fe7e987a9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a0e00113872f921116b6c0c3177d0f.png)
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解题方法
3 . 如图,四棱锥
中,底面
为正方形,
底面
,
为
的中点.
平面
;
(2)求证:平面
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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa69a2247ad4d5231aa361349b12f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
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2023-08-10更新
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887次组卷
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3卷引用:广西壮族自治区南宁市东盟中学2023-2024学年高二上学期开学考试数学试题
广西壮族自治区南宁市东盟中学2023-2024学年高二上学期开学考试数学试题陕西省西安市第六十六中学2022-2023学年高一下学期第二次月考数学试题(已下线)专题训练:线线、线面、面面平行与垂直证明大题-同步题型分类归纳讲与练(人教A版2019必修第二册)
名校
4 . 已知△
中,
,求证
.
证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf7efa75e1f580910d41d954bc911cd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0caa3e6a0de075df4c9a869dfed4bf20.png)
画线部分是演绎推理的( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37c0ad68bf0ca0d00461a269df127af5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a46e678bf9d2df5ad4c782b3dc22f5.png)
证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf7efa75e1f580910d41d954bc911cd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0caa3e6a0de075df4c9a869dfed4bf20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bf1aa83a61bd003e09b68d51af984a4.png)
A.大前提 | B.三段论 | C.结论 | D.小前提 |
您最近一年使用:0次
2017-07-15更新
|
217次组卷
|
3卷引用:广西陆川县中学2017-2018学年高二下学期开学考试数学(文)试题
名校
5 . 如图(1),在
中,
,
,
,
分别是
,
的中点,将
和
分别沿着
,
翻折,形成三棱锥
,
是
中点,如图(2).
(1)求证:
平面
;
(2)若直线
上存在一点
,使得
与平面
所成角的正弦值为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8e9ec412ea0355e4e5cd06c60e5fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0e7d395bc97771671c5001a52138313.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad09a769a75b107390b9eeccc929f761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212b200cb65843fe03aab377d53991d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/20/c9c51067-307b-48e7-a4df-d5298c2b636d.png?resizew=189)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7442b64b37f685bc3ae88ff450c1a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf3d566704b44ea4ef1f99c37bd46902.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/785f4eb0787ffc744fb1018f0c6c347f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db8305c4ffbf876642440c3d28e91e9f.png)
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2024-02-04更新
|
242次组卷
|
2卷引用:广西柳州市柳州高级中学2023-2024学年高二上学期开学考试数学试卷
6 . 如图,在四棱锥
中,四边形
是菱形,
底面
,
,
.点E是棱
的中点.
;
(2)求平面
与平面
夹角的余弦值.
![](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/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3b10835116b9b777a666b438c907b49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4125524caac016727c80d2722c5ba3.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
您最近一年使用:0次
7 . 已知数列
是正项等比数列,
是等差数列,且
,
,
,
(1)求数列
和
的通项公式;
(2)
表示不超过x的最大整数,
表示数列
的前
项和,集合
共有4个元素,求
范围;
(3)
,数列
的前
项和为
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd5c206e70fdd64f4a3271fa68e5b2ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c519b98e1955f805ad21af88991e0e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/471584358a4c23a08378b2d8fa02c8c4.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f161c2a3717f1b6c62d0d7dae0b606.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ef48976a52cc4a2be7c46a98426c0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c10588e175c133b5387712aae98af243.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b17a9b9bb8bf6bb9865e37f204da5c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14e16e1c1834634d4b30d9f31e060678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0174f17b1d390bdb979d33afe3625011.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5ab0309e2cd35585ea9fb2cc3017abf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d51f9147b8265c0276c1f2c2659197.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b9a0d7150fb24be3e28ef7f0e18be93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27f571bc084678145358463c81ea8d55.png)
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2024-01-22更新
|
925次组卷
|
2卷引用:广西部分学校2024届高三下学期开学考试数学试题
解题方法
8 . 已知正项数列
,其中
,且
.
(1)设
,证明:数列
是等比数列,并求其通项公式;
(2)设
,求数列
的前
项和
,并判断是否存在正整数
,使得
为整数,若存在,请求出最小正整数
;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26da1b47c587cb779054b63c84d3220c.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a61a9ba3f0b6e3522caa49ce5ca96405.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a306bbf6ae0f4f1abf9f4f7248fefb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次
名校
9 . 如图,四边形ABCD是圆柱OE的轴截面,点F在底面圆O上,
,
,点G是线段BF的中点.
平面DAF;
(2)求直线EF与平面DAF所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3dc56d3c645f14375774cc15f7ba7fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f31d54d125c042169e282f14eddd45a1.png)
(2)求直线EF与平面DAF所成角的正弦值.
您最近一年使用:0次
2023-09-15更新
|
838次组卷
|
3卷引用:广西桂林市第十八中学2023-2024学年高二上学期开学考试数学试卷
10 . 已知A,B为抛物线C:
上的两点,△OAB是边长为
的等边三角形,其中O为坐标原点.
(1)求C的方程.
(2)过C的焦点F作圆M:
的两条切线
,
.
(i)证明:
,
的斜率之积为定值.
(ii)若
,
与C分别交于点D,E和H,G,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b6d8eaacc2d999b37209feba103f9ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6093eebca8f3ff82ce9298feb197e955.png)
(1)求C的方程.
(2)过C的焦点F作圆M:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15fc1af2a824c1f6a0aa4618e5e6dfa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
(i)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
(ii)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f160e6da63385867807453959174f41.png)
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