名校
解题方法
1 . 为了解推动出口后的亩收入情况,从该种植区抽取样本,得到推动出口后亩收入的样本均值
,样本方差
,已知该种植区以往的亩收入
服从正态分布
,假设推动出口后的亩收入
服从正态分布
,则( )(参考:若随机变量
服从正态分布
,
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d1e75c0fb70228642ce0bcde6a71349.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39a23d14a37c1a373f8a8c6dbceab073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a07ca75c28a47c73d627e060b7c901b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/181e591ecb49049125491fc4ca62369c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8b9ad2fcfff3dd546c5fdbedfe6238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bcc248a7770a16fa10fc4602d71e0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a79c125ea0d4c8744d4dba3681b77ca.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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2 . 如图,矩形
中,
,
,
为边
的中点,沿
将
折起,点
折至
处(
平面
),若
为线段
的中点,平面
与平面
所成二面角
,直线
与平面
所成角为
,则在
折起的过程中,下列说法正确的是()
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8588e18e27bfebf7c81c7e3c7efb1149.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/483f030abf61c6a0882d656d63cf4512.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/483f030abf61c6a0882d656d63cf4512.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
A.存在某个位置,使得![]() |
B.![]() ![]() |
C.![]() |
D.三棱锥![]() ![]() ![]() |
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解题方法
3 . 如图, 在
中,
为
的中点,
,
与
交于点
,若
,则下面对于
的描述正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/122fe84cfa345c1902231699c96beac2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833d37b9c21319f3965bb4d19c9ebe72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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解题方法
4 . 已知△ABC的内角A,B,C所对的边分别为a,b,c,下列四个命题中正确的命题,( )
A.若![]() ![]() |
B.若![]() ![]() ![]() |
C.若![]() |
D.若![]() |
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5 . 甲、乙、丙、丁、戊五名同学站一排,下列结论正确的是( )
A.不同的站队方式共有![]() |
B.若甲和乙相邻,则不同的站队方式共有![]() |
C.若甲、乙、丙站一起,则不同的站队方式共有![]() |
D.甲不在两端,则不同的站队方式共有![]() |
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6 . 已知函数
,直线
则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc68c31be0ba07c12c812326c0657558.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/766b5c86a384941acb1832b5b041c759.png)
A.函数![]() ![]() |
B.![]() ![]() |
C.若直线![]() ![]() ![]() |
D.若直线![]() ![]() ![]() ![]() |
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7 . 已知曲线![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fdc384aa20e27b9289497e741e35554.png)
,下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fdc384aa20e27b9289497e741e35554.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af6383d7fbb4630f424a6ad10fdfe2f4.png)
A.曲线![]() |
B.当![]() ![]() |
C.若![]() ![]() ![]() |
D.若![]() ![]() |
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解题方法
8 . 已知
为坐标原点,抛物线
的焦点为
,过
的直线
与
交
,
两点,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37ab7408ffcefcb8e5e1ad4a9c58f1b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/092fd1b1d33979818300cd2e3699bff7.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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a3efb79f35db8448f3391252ab7d4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8df332f01628130c084fd46aaca0a4b7.png)
A.![]() | B.若![]() ![]() ![]() |
C.若直线![]() ![]() | D.![]() |
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解题方法
9 . 已知等差数列
的前n项和为
,
,下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34c0e966db2d11c9dba1454ac6fcb8e4.png)
A.等差数列![]() | B.等差数列![]() |
C.![]() | D.当![]() ![]() |
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10 . 下列求导正确的是( )
A.![]() | B.![]() |
C.![]() | D.![]() |
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