名校
1 . 有40个数据,其中最大值为46,最小值为15,若取组距为4,则应该分的组数是______ .
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2 . 综合与探究:
如图,在平面直角坐标系中,抛物线
与
轴交于点
,点
,交
轴于点
,顶点为
,连接
,
.
(2)点
是直线
下方抛物线上的一动点,过点
作
交
轴于点
,
轴交
于点
.
①当
时,点
的坐标为 .
②求
的最大值;
③连接
并延长
交
轴于点
,点
为
轴上的一个动点,连接
,则
的最小值为 .
如图,在平面直角坐标系中,抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9553fb9beb9ed49ea5f7a0f077884d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8950c7bc835103d52ceffab14b6b31a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0c34f23f45d511636fb46dc31913103.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c04a48b5c5a4d65b7cd999c678d9161.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/362cdc132883c8de75c429b9f67fad5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9790f8ad686ecfd880f291d6c94cf800.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
②求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35d58f9019097bd05037aefd5c322916.png)
③连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84d454c82d9e52747563d47b68099249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ca1b675ad6a0e5c78029c996a05d529.png)
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3 . 平面直角坐标系中,已知抛物线
(a是常数,且a<0),直线
过点![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5905cfcc5af4b01d63237486eb6d295.png)
且垂直于y轴.当
时,沿直线
将该抛物线在直线上方的部分翻折,其余部分不变,得到新图象G,图象G对应的函数记为
,且当
时,函数
的最大值与最小值之差小于7,则n的取值范围为_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fcbe4989354eb372db6e2f46868d49c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5905cfcc5af4b01d63237486eb6d295.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/884716e0491ba125850f31e54797f30a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f4029de9bf789ec67b8bbaaf43ce493.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53b89bf0edf4e0e4ebe377a0dc6791b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
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4 . 为进一步落实“德、智、体、美、劳”五育并举工作,某校开展以“文化、科技,体育、艺术劳动”为主题的活动,其中体育活动有“一分钟跳绳”比赛项目,为了解学生“一分钟跳绳”的能力,体育老师随机抽取部分学生进行测试并将测试成绩作为样本,绘制出如图所示的频数分布直方图(从左到右依次为第一到第六小组,每小组含最小值,不含最大值)和扇形统计图,请根据统计图中提供的信息解答下列问题:
(2)求第四小组的频数,并补全频数分布直方图;
(3)若“一分钟跳绳”不低于160次的成绩为优秀,本校学生共有1800人,请估计该校学生“一分钟跳绳”成绩为优秀的人数.
(2)求第四小组的频数,并补全频数分布直方图;
(3)若“一分钟跳绳”不低于160次的成绩为优秀,本校学生共有1800人,请估计该校学生“一分钟跳绳”成绩为优秀的人数.
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2024-04-12更新
|
127次组卷
|
3卷引用:2024年黑龙江省哈尔滨市南岗区中考二模数学试题
名校
5 . 一组数据最大值为35,最小值为13,若取组距为4,列频数分布表时应分( )组.
A.4 | B.5 | C.6 | D.7 |
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2024-03-05更新
|
144次组卷
|
4卷引用:黑龙江省哈尔滨市南岗区第十七中学校2021-2022学年七年级上学期开学考试数学(五四制)试题
黑龙江省哈尔滨市南岗区第十七中学校2021-2022学年七年级上学期开学考试数学(五四制)试题江苏省盐城市东台市第二教育联盟2023-2024学年八年级下学期3月月考数学每年一次试题河北省唐山市乐亭县2023-2024学年八年级下学期期中数学试题(已下线)专题01 数据的收集、整理和描述(七大类型)(题型专练)-2023-2024学年七年级数学下册《知识解读·题型专练》(人教版)
6 . 【阅读材料】
材料一:对于实数x,y定义一种新运算K,规定:
(其中a,b均为非零常数),等式右边是通常的四则运算.比如:
;
.
已知:
;
.
材料二:“已知x,y均为非负数,且满足
,求
的范围”,有如下解法:
∵
,∴
,
∵x,y是非负数,∴
即
,∴
,
∵
,∴
,
∴
.
【回答问题】
(1)求出a和b的值;
(2)已知x,y均为非负数,
,求
的取值范围;
(3)已知x,y,z都为非负数,
,
,求
的最大值和最小值.
材料一:对于实数x,y定义一种新运算K,规定:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65b62ab6c677efa765b83a50b4cb654d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bba43b4e571af4e57135551281c7f8a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57511936c521ca08faf960edb19f5ef7.png)
已知:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/688a14b94680a2c423a38833043b464a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e17110db5e9c3473e871bc87f97cf974.png)
材料二:“已知x,y均为非负数,且满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31b9442c77f394e24f722e626d85d249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc6f3c30a6691c86db14441bd51d777d.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31b9442c77f394e24f722e626d85d249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf4c7796d1d6f70e0a29c5e44c6a37c5.png)
∵x,y是非负数,∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6e2e79843faf62dde86bf858d1e0569.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f76d442028072ba1e8a93cd4628ac9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58fe8db7b7c8b2ef5a8746d18f033497.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4141573d4ec02d94680bb2f2e2ae2bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9e63f42a7481d7a33af76c709e25b9e.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c99c334b37f1b141989c84879f9c5f.png)
【回答问题】
(1)求出a和b的值;
(2)已知x,y均为非负数,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/139f7fbbd43de313e2654685d01c5ce8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca32ccf5ce4b19ce83c2f54cf61797b1.png)
(3)已知x,y,z都为非负数,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fcddd5568d4deef1aba223224a24a19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/968da0e69381863124cd1e5fe3ac2548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f40bc2ae40a15966072ca5d0b252c7.png)
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7 . 综合与实践
利用正方形纸片的折叠开展数学活动,探究体会在正方形折叠过程中,图形与线段的变化及其蕴含的数学思想方法.
如图①,E 为正方形
的
边上的一个动点,
,将正方形
对折,使点
与 点
重合,点
与 点
重合,折痕为
.
(1)将正方形
展平后沿过点
的直线
折叠,使点
的对应点
落在
上,折痕为
, 连接
, 如图②,请根据以上条件填空.
①点
在以点
为圆心, 的长为半径的圆上(填线段);
②
的长为 ;
拓展延伸
(2)当
时,正方形
沿过点
的直线
(不过点
)折叠后,点
的对应点
落在正方形
的内部或边上.
① 求
面积的最大值;
② 连 接
,
为
的中点,点
在
上,连接
求
的最小值.
利用正方形纸片的折叠开展数学活动,探究体会在正方形折叠过程中,图形与线段的变化及其蕴含的数学思想方法.
如图①,E 为正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/377f5c10cf527c87ab06bff61384f7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
(1)将正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9171484a68c84cad91e4f2233392f600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da650ee630c36fd5ce9abb4fb826df7b.png)
①点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83f00d88b9f850dea09aa8c682b9d610.png)
拓展延伸
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b97878915ceefd7aeccb156bc318b5da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
① 求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19343455668abab3ca3b05aa2cf616c2.png)
② 连 接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/943712a5e96b16cc15d775cc4687237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/943712a5e96b16cc15d775cc4687237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5c762edb7f688b96c33eb3ada9c3da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0eaadeeb52e7729fe8d6bdd736eaa783.png)
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8 . 如图1,在平面直角坐标系中,抛物线
与x轴交于点A,B(点A在点B的左侧),交y轴于点C,点A的坐标为
,点D为抛物线的顶点,对称轴与x轴交于点E.
(2)连接
,点M是线段
上一动点(点M不与端点B,D重合),过点M作
,交抛物线于点N(点N在对称轴的右侧),过点N作
轴,垂足为H,交
于点F,点P是线段
上一动点,当
的周长取得最大值时,求
的最小值;
(3)在(2)中,当
的周长取得最大值时,
取得最小值时,如图2,把点P向下平移
个单位得到点Q,连接
,把
绕点O顺时针旋转一定的角度
,得到
,其中边
交坐标轴于点G.在旋转过程中,是否存在一点G,使得
?若存在,请直接写出所有满足条件的点
的坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10e71461c5134339b5b54a80e588640f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97b3c94d505e7c5bcce94afec4af3d92.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee50a23604ea2a9c1f3649dab97c2e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/150cbaad560246d84e6411c69dfb6718.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a33181b27b10690b4913595f8c1f46e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d830ff97422da8d6d4911ef6f22af4.png)
(3)在(2)中,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a33181b27b10690b4913595f8c1f46e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d830ff97422da8d6d4911ef6f22af4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18483c9c195ecd922772527fa85c0fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84d454c82d9e52747563d47b68099249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/831c4fbec375b0bfc8258ed9b1a81ef8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d01f5c4d4177269ecb4b323defa063a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a50876b3f3f74193245abaa84262ecee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f159bdf3e82d6b58ad696ed844ab6d5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f94a5ff197dc688cc8cd754154c152f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a42da28be159399514cc6179a96e34b.png)
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名校
9 . 教科书中这样写道:“形如
的式子称为完全平方式“,如果一个多项式不是完全平方式,我们常做如下变形:先添加一个适当的项,使式子中出现完全平方式,再减去这个项,使整个式子的值不变,这种方法叫做配方法.配方法是一种重要的解决问题的数学方法,不仅可以将一个看似不能分解的多项式分解因式,还能解决一些与非负数有关的问题或求代数式最大值、最小值等问题.
例如:分解因式:
.
解:原式
再如:求代数式
的最小值.
解:
,可知当
时,
有最小值,最小值是
.
根据阅读材料,用配方法解决下列问题:
(1)分解因式:
________.(直接写出结果)
(2)当x为何值时,多项式
有最大值?并求出这个最大值.
(3)利用配方法,尝试求出等式
中a,b的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e497fe36c69d28917c3eb8ba43d19f19.png)
例如:分解因式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/527ed5ec08bfac2d403309c2ee8256b6.png)
解:原式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e87f290937c3977a9d8077f09652005.png)
再如:求代数式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66a0e6a1abebd0e654515ae5872c2454.png)
解:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e27a04ddc71db55a7ae8588f6acb9506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99c6875d552e9fff3c7d655f3a59b166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66a0e6a1abebd0e654515ae5872c2454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cf937cd469db1fe08e82724baeab7b6.png)
根据阅读材料,用配方法解决下列问题:
(1)分解因式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e91f2bf843ab72ee967639e703902b36.png)
(2)当x为何值时,多项式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ada629dc4462bbdf5f7759f3c5bb875.png)
(3)利用配方法,尝试求出等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6a5a9eb05ed5d4f70079e147c56abe.png)
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2023-12-25更新
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4卷引用:黑龙江省哈尔滨市第一0七中学校2023-2024年八年级上学期期末数学试题
10 . 在统计中,样本的方差可以近似的反映总体的( )
A.最大值与最小值 | B.平均状态 |
C.分布规律 | D.波动大小 |
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