解题方法
1 . 如图
,在直角梯形
中,
,
,
,
是
的中点,
是
与
的交点.将
沿
折起到
的位置,如图
.
平面
;
(2)若平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
平面
,求平面
与平面
夹角的余弦值.
![](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/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53b94651d11df3a469d7ac72e6ac74c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d78aafccd397e9c88a567abf4993d40f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcdfe7976bd3f16bfef5c6f1b4f20f23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/306b9504b52df5ad6697fa87200e8a44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eddaf3f33bd9a99162c061c9dd99aee.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
您最近一年使用:0次
解题方法
2 . 函数
的部分图象大致是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e0c12e92dd9a4d00e2107ce931ac5bb.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
解题方法
3 . 在正方体
中,点
满足
,
,
,则( )
![](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/a1be5693b11b4198a234beb9cf3226d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee72261f6901e62dfd0ffe547406544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e2e01346f60857ff635bb766802e57.png)
A.当![]() ![]() |
B.当![]() ![]() |
C.当![]() ![]() ![]() ![]() |
D.当![]() ![]() ![]() |
您最近一年使用:0次
4 . 已知圆
与抛物线
相交于两点
,分别以
为切点作
的切线
. 若
都经过
的焦点
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba780c5282394b70aabaa176594a88ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e6c830bfa9a1b979a1a9665166424bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44434b647ec546fe787e2164e0be6cd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44434b647ec546fe787e2164e0be6cd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba45bf9858b881250ba29b0e114d79d3.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
5 . 如图,在三棱柱
中,
为
的中点,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/12/64214607-5260-487a-995a-6d376131a4f0.png?resizew=173)
(1)求证:
;
(2)求平面
与平面
夹角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.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/10c013bbe1fb6e9acf461548b5cf6cd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc11331a7b2d2619b40ee6d34c3bd620.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf2800c9fab90fb82200f5ac496969c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dc8e303f32044b1438b811d8dc82d6b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/12/64214607-5260-487a-995a-6d376131a4f0.png?resizew=173)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac2ef99db257cc1acb08e3a5e0006d49.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e46fca7d5918b0572984aa3143f182a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次
6 . 已知
分别是椭圆
的左,右焦点,
是
上两点,且
,
,则
的离心率为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d2a97987f71835f519b462f5b8f5957.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/851a5d6ec23256f9b4a9e98aa92945fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df6b3c8ff227480fe31006692abdaaa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42af5fd2a574873069ca940d57bdbcbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
您最近一年使用:0次
解题方法
7 . 平面内点
到点
与到直线
的距离之比为3.
(1)求点
的轨迹
的方程;
(2)
为
的左右顶点,过
的直线
与
交于
(异于
)两点,
与
交点为
,求证:点
在定直线上.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2254f7a85430f9c0b1adf193318dbf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82daff095e3184c8e4f42b0f547d6e3d.png)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00442d96d695db2c58bf1fb7165fca94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00442d96d695db2c58bf1fb7165fca94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbe61d39d080872caa8973a70a3b4955.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a439c8a01a6626d7a3f53af31ef0bcae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
您最近一年使用:0次
8 . 定义:设
和
均为定义在
上的函数,它们的导函数分别为
和
,若不等式
对任意实数
恒成立,则称
和
为“相伴函数”.
(1)给出两组函数,①
和
;②
和
,分别判断这两组函数是否为“相伴函数”;
(2)若
是定义在
上的可导函数,
是偶函数,
是奇函数,
,问是否存在
使得
和
为“相伴函数”?若存在写出
的一个值,若不存在说明理由;
(3)
,写出“
和
为相伴函数”的充要条件,证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0afb80007983e5b99dcdeebf87d18ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb2faa63899873813748f6a28b8a92e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/933093b52cca887f597cbe22a5467b11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090a91e4f3c8930674f98a9fa527709b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/783c88951a458d5862557f2a041f817a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/641d65f51ea7487fd84aa8d1fbcc3b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0afb80007983e5b99dcdeebf87d18ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb2faa63899873813748f6a28b8a92e9.png)
(1)给出两组函数,①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/125fb6edbb4d5a9f93199816b8c0a8d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f45b5ff5ad4070bf0172149c660b224.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2acd9e80f792e815194dd0c815f30fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a613c6202de44ac9d557e4ce75ca5ef6.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f103e9b807e576b1954d91009a26d463.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/933093b52cca887f597cbe22a5467b11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0afb80007983e5b99dcdeebf87d18ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb2faa63899873813748f6a28b8a92e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03318fa1c9b6a20bf3aa1630f161c6c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ee0f7141d44f242b4cf730e9fd2175.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0afb80007983e5b99dcdeebf87d18ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb2faa63899873813748f6a28b8a92e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2ca68c4a017731b7fe3d3e2d81da6c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0afb80007983e5b99dcdeebf87d18ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb2faa63899873813748f6a28b8a92e9.png)
您最近一年使用:0次
9 . 某高中为了了解学生参加数学建模社团的情况,采用了分层随机抽样的方法从三个年级中抽取了300人进行问卷调查,其中高一、高二年级各抽取了90人.已知该校高三年级共有720名学生,则该校共有学生______ 人.
您最近一年使用:0次
解题方法
10 . 为了解学生中午的用餐方式(在食堂就餐或点外卖)与最近食堂间的距离的关系,某大学于某日中午随机调查了2000名学生,获得了下面的频率分布表(不完整),并且由该频率分布表,可估计学生与最近食堂间的平均距离为
(同一组数据以该组数据所在区间的中点值作为代表).
(1)求出
的值并补全频率分布表;
(2)根据频率分布表补全样本容量为
的
列联表(如下表),并根据小概率值
的独立性检验,能否认为学生中午的用餐方式与学生距最近食堂的远近有关(当学生与最近食堂间的距离不超过
时,认为较近,否则认为较远);
根据频率分布表列出如下的
列联表:
(3)一般情况下,学生更愿意去饭菜更美味的食堂就餐.该校距李明较近的有甲、乙两家食堂,且他每天中午都选择食堂甲或乙就餐.记他选择去甲食堂就餐为事件A,他认为甲食堂的饭菜比乙食堂的美味为事件D,且D、A均为随机事件,证明:
.
附:
,其中
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc799084b142019f173728370a7bc32e.png)
学生与最近食堂间的距离![]() | ![]() | ![]() | ![]() | ![]() | ![]() | 合计 |
在食堂就餐 | 0.15 | 0.10 | 0.00 | 0.50 | ||
点外卖 | 0.20 | 0.00 | 0.50 | |||
合计 | 0.20 | 0.15 | 0.00 | 1.00 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(2)根据频率分布表补全样本容量为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4abb59695562b3a1295a251dc97da700.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83caa0ad94044a1e206b1cc0b3f85080.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f05ba29eb90358e2211e1f7ba6423fa2.png)
根据频率分布表列出如下的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
学生距最近食堂较近 | 学生距最近食堂较远 | 合计 | |
在食堂就餐 | |||
点外卖 | |||
合计 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/169d6162056f4486756c34256f5a4cd7.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2187714e660234f0b72f2b47d3ea685a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
![]() | 0.10 | 0.010 | 0.001 |
![]() | 2.706 | 6.635 | 10.828 |
您最近一年使用:0次