1 . 将两个变量x、y的n对样本数据
,
,
,…,
在平面直角坐标系中表示为散点图,根据x、y满足一元线性回归模型及最小二乘法,求得其经验回归方程为
.设
为回归直线上的点,则下列说法正确的是________ .
①
越小,说明模型的拟合效果越好;
②利用最小二乘法求出的线性回归直线一定经过散点图中的某些点;
③相关系数r的绝对值越接近于1,说明成对样本数据的线性相关程度越强;
④通过经验回归方程进行预报时,解释变量的取值不能距离样本数据的范围太远,求得的预报值不是响应变量的精确值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56720e2f2b0ddd72156da495923698da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2852ae85cfcc804b3192ea8543c88938.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1947266946e35d8f997e6572c27ac6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92abae836b8026511113ad8c3ea23028.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db6103cb0f1d2bd6b19235d53ee7e98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61bd0c278333487ac201caa73915dca0.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e45576c48ad73b592a48680fa6a7189c.png)
②利用最小二乘法求出的线性回归直线一定经过散点图中的某些点;
③相关系数r的绝对值越接近于1,说明成对样本数据的线性相关程度越强;
④通过经验回归方程进行预报时,解释变量的取值不能距离样本数据的范围太远,求得的预报值不是响应变量的精确值.
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解题方法
2 . 设
,利用三角变换,估计
在
时的取值情况,猜想对x取一般值时
的取值范围是____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daefb8bfca63d0f5e3e9a87ae92ccc7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c1ba6b6ee00c4b2763cb3fa59caa69f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17fb5433a783bf61acf957358a0d382d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c1ba6b6ee00c4b2763cb3fa59caa69f.png)
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2023-03-18更新
|
220次组卷
|
2卷引用:江苏省南通市海安高级中学2022-2023学年高一下学期阶段检测(一)数学试题
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3 . 在下列命题中,正确的命题有________ (填写正确的序号)
①若
,则
的最小值是6;
②如果不等式
的解集是
,那么
恒成立;
③设x,
,且
,则
的最小值是
;
④对于任意
,
恒成立,则t的取值范围是
;
⑤“
”是“复数
(
)是纯虚数”的必要非充分条件;
⑥若
,
,
,则必有
;
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ef389807e5cb964f7756c6841f7161d.png)
②如果不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fae8fff7c98b78992edcd61daf6ea72f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef7b2668d8fcf713370822c8e368ba7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4da693578d4cd0c841fd529fe7ebfe4d.png)
③设x,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2519954ec2deabecd7e057886fa4023c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5558c083d34cbb0a58d3ce1dc6f5778e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa8887f77124cbe18a4931826ede9c9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
④对于任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b687f97094676b2755bc724219a58520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10ce220e0583c843810d4b44de111156.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f49bc53d70ee599df5cad39f06f728c2.png)
⑤“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f22a4a0dd7307a1323d25331e60782d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21d96d22950baabd8ca6647205f1d3cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1e69392d21261afd8e5e5f096634669.png)
⑥若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae2e606c883dace7fbd88223c8067885.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9d3040a7a1fc2cf8ac555dbafc97dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc277eef249facf647e13a58e3c2fe26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/297a7062ba8f240d7517f0dd3ee6a27d.png)
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