1 . 某投资公司现从甲投资研究室(
人)、乙投资研究室(
人)中随机选出
名资深投资顾问对某项目进行考察投资.
(1)记选出的
名资深投资顾问中,甲投资研究室的人数为
,求
的分布列和均值;
(2)为给投资提供决策依据,资深投资顾问对此项目的
个子项目调查了年研发经费
(单位:万元)和年销售额
(单位:十万元),并对数据进行了初步处理,得到一些统计量的值:
,
,
,
,根据散点图认为
关于
的经验回归方程为
,求
与
的值(结果精确到
).
参考公式:
,其中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
(1)记选出的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(2)为给投资提供决策依据,资深投资顾问对此项目的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ea8f47d8d8d9e1832d52b1c7425450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4de122ae929b1acaff321dec137622ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7756f25833e524da5a57715ef312186.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713be36305fc8a06011cddeb34a05ed9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c36d445455548fa9c9265e92f6692ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05d542a22a43aa972991aef5881c773f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db6103cb0f1d2bd6b19235d53ee7e98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0032ca31e3cba58f973c6e75b907fb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc5505526d11946ca7d3a4421a9e08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a87796ee30e6c5d5e6b6285b32abe10c.png)
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a58291bd91befe1061530246da983727.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2dbdbf02e0dd324daba7488c3e3bf31.png)
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解题方法
2 . 已知
内角
的对边分别为
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa1e8a0aaf1c900d3bb0646635e7938b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0115be544ac8554a79093823f616aa1.png)
.
(1)求A;
(2)A的平分线
交
于
点,
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa1e8a0aaf1c900d3bb0646635e7938b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0115be544ac8554a79093823f616aa1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ee6a2f02cdc7d6e7c4eadb5dd0ff012.png)
(1)求A;
(2)A的平分线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dccd0715a4e339996ab52e76e8ef0c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
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解题方法
3 . 正方体
的棱长为
,
分别为
上的点,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bac8911246624118ff506edd4eb14e9.png)
,
分别为
上的动点.若点
在同一球面上,当
平面
时,该球的表面积为 ______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3304e23f3b0f9569c4140ca89b6498.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3657e945e364488df6ba6922d6a25229.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bac8911246624118ff506edd4eb14e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0204f76cda5ea4ced714588be1efeaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36080e182835de5da4c2d016fd40bf49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3ec0cf152e35708d87a83cb4cb56461.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b61346bd4091070ba84a4046f87f365.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
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4 . 已知
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87564738fb1cc44f35fda7cf961cdc70.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c194f17325e5c2ec60ca016b8b4aa80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87564738fb1cc44f35fda7cf961cdc70.png)
您最近一年使用:0次
解题方法
5 . 已知数列
的通项公式为
,前
项和为
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0604dd7db130ed9402391d319379eae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
A.数列![]() ![]() |
B.使![]() ![]() |
C.满足![]() ![]() ![]() |
D.使![]() ![]() |
您最近一年使用:0次
6 . 已知直线
,圆
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cce659f89df2309b4e319b57e1d588b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f8455d966f9ed850e9882e4ebf06aec.png)
A.圆心![]() ![]() |
B.直线![]() ![]() |
C.当![]() ![]() ![]() ![]() ![]() ![]() |
D.点![]() ![]() ![]() |
您最近一年使用:0次
解题方法
7 . 已知抛物线
的焦点为
,
上一点
到焦点
的距离为
,过焦点
的直线
与抛物线交于
两点,则
的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82ea1be9b9b6bb12afa7e1ce703d1603.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f786b33c4a54b7db3b01b2bb4c642b4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.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/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7afd91121bcd66f82a5186205b676bd9.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
8 . 已知函数
在区间
上单调递增,则
的最大值( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fa5e01a42421e4aabee073b6f552f18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f114df5ceabdb7e5fd3fdad4eaf056.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
解题方法
9 . 若
, 则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca7532b296f7c2bfb2ec2bf9ead4d0f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00a080cab44a7d3605430d67b207f9be.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
解题方法
10 . 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