1 . 某数学实验小组在探究“关于x的二次三项式ax2+bx+3的性质(a、b为常数)”时,进行了如下活动.
【实验操作】取不同的x的值,计算代数式ax2+bx+3的值.
(1)根据上表,计算出a、b的值,并补充完整表格.【观察猜想】实验小组组员,观察表格,提出以下猜想.同学甲说:“代数式ax2+bx+3的值随着x的增大而增大”.同学乙说:“不论x取何值,代数式ax2+bx+3的值一定不大于4”.…
(2)请你也提出一个合理的猜想: 【验证猜想】我们知道,猜想有可能是正确的,也可能是错误的.
(3)请你分别判断甲、乙两位同学的猜想是否正确,若不正确,请举出反例;若正确,请加以说理.
【实验操作】取不同的x的值,计算代数式ax2+bx+3的值.
x | … | ﹣1 | 0 | 1 | 2 | 3 | … |
ax2+bx+3 | … | 0 | 3 | 4 | … |
(2)请你也提出一个合理的猜想: 【验证猜想】我们知道,猜想有可能是正确的,也可能是错误的.
(3)请你分别判断甲、乙两位同学的猜想是否正确,若不正确,请举出反例;若正确,请加以说理.
您最近一年使用:0次
2020-03-23更新
|
213次组卷
|
2卷引用:江苏省扬州市江都区2018-2019学年七年级下学期期末数学试题
2 . 已知抛物线
:
的顶点为
,抛物线
:
的顶点为
.命题1:如果点
在抛物线
上,那么点
也在抛物线
上;命题2:如果点
不在抛物线
上,那么点
也不在抛物线
上.下列说法中,正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90385c676848de67293e3ed6bc000fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec0df57c2de018bacbec7391836ae9a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.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/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.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/ac047e91852b91af639feec23a9598b2.png)
A.命题1是真命题,命题2也是真命题 | B.命题1是真命题,命题2是假命题 |
C.命题1是假命题,命题2是真命题 | D.命题1是假命题,命题2也是假命题 |
您最近一年使用:0次
名校
3 .
是
的二次函数,其对应值如下表:
下列叙述不正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![]() | |… | ![]() | 0 | 1 | 2 | 3 | 4 | … |
![]() | … | 4 | ![]() | 0 | 1 | 4 | 9 | … |
A.该二次函数的图象的对称轴是直线![]() |
B.![]() |
C.当![]() ![]() ![]() |
D.图象与![]() |
您最近一年使用:0次
2023-07-24更新
|
341次组卷
|
7卷引用:江苏省盐城市东台市第五教育联盟2022-2023学年九年级上学期12月月考数学试题
江苏省盐城市东台市第五教育联盟2022-2023学年九年级上学期12月月考数学试题江苏省徐州市泉山区科技中学2023-2024学年九年级上学期9月月考数学试题江苏省苏州市苏州中学校2023-2024学年九年级上学期10月月考数学试题北京市广渠门中学2023-2024学年九年级上学期期中数学试题江苏省南通市实验中学2023-2024学年九年级上学期期末数学试题(已下线)第07讲 二次函数与一元二次方程(知识解读+真题演练+课后巩固)-2023-2024学年九年级数学下册《知识解读·题型专练》(苏科版)(已下线)专题03用待定系数法确定二次函数表达式(1个知识点5种题型1个中考考点)-【帮课堂】2023-2024学年九年级数学下册同步学与练(苏科版)
名校
4 . 已知二次函数
,其中自变量x与函数值y之间满足下面的对应关系:
下列判断中,正确的是________ (填序号).
①顶点是
②
③
④当
时,
⑤当
时,y随着x的增大而减小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8352b2e643a7ce605334f1b0e572bfb0.png)
x | … | 2 | 3 | 4 | … | |
y | … | 4.8 | … |
①顶点是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a415da14a18018d72dff4ccab8ceb4f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e10e1c43b86a8cd4360ca9b57232164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9deb79d044a379f31a8fc57736d7ead.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/639c3d2ff5ee566fcc1b69c65712a661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b84a53ebd6f6d4e777742346c3b9bb8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/399352f781001d894b4c33d309d01c64.png)
您最近一年使用:0次
5 . 已知m,n为整数,抛物线(b为常数)经过点
,
.现有两个命题:①若
,则
与
可能相等;②若
,则
与
可能相等.则下列说法正确的是( )
A.①,②都是真命题 | B.①,②都是假命题 |
C.①是真命题,②是假命题 | D.①是假命题,②是真命题 |
您最近一年使用:0次
6 . 如图,函数
的图象的顶点为
,下列判断正确个数为①
;②
;③
;④点
和点
都在此函数图象上,则
;⑤
.以上结论正确的是______ .(填序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de540364449219af5e2780977004a83d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/546fa3a474cafbbbf237ee6b6aee1652.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94ed37ee7432002cd0e0978b2012e184.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/308bf6149fb83d38e76f8ea8b29dd1af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8befcbb1bacb08bbb3a51446df1a606.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ad1bd0239b05c264839f603e9d97249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3fb7193c308c6e069eab5e13cb6ac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1292c47f62023b747f1a4bd615c75284.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/623892573147c930c3efca3dfef89cb3.png)
您最近一年使用:0次
7 . 已知抛物线
的对称轴为直线
,并与坐标轴的一个交点为
,其部分图象如图所示,下列判断中:①
;②
;③
;④
;⑤若点
,
均在抛物线上,则
,其中正确的判断是_______ .(填写所有正确判断的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90385c676848de67293e3ed6bc000fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef00713e73b8357cc7900144f5505bc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53a948d2f7732d7f03e986c63712089b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73c21bd0bd90a89b7ff5ac0eacf612a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4630bb948780be53bc73d9ddef875000.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69a0db70be7145f74c092d6561d447e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21d5218ac205f3e074bd4114fe95f72d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d86529e1bd6e6cdf3838cf9c7ca6e25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbdc6e14577fbcc8fd26ad13faff3c32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ac67e9a909472ab852d38d2ec66a1e1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/22/f1999bc8-ed7d-4255-ba24-bb0ecc06f4db.png?resizew=143)
您最近一年使用:0次
2023-10-20更新
|
124次组卷
|
3卷引用:广东省广州美术学院附中2022-2023学年自主招生数学试题
名校
8 . 如图,抛物线
交
轴于点
,与
轴的一个交点在
和
之间,顶点为
,下列说法:其中正确判断的序号是( )
![](https://img.xkw.com/dksih/QBM/2023/1/15/3153561642450944/3238784995942400/STEM/e7f5a4bb23eb452ca1d0e3d8fbf4f8f9.png?resizew=154)
①抛物线与直线
有且只有一个交点;
②若点
,
,
在该函数图象上,则
;
③将该抛物线先向左,再向下均平移
个单位,所得抛物线解析式为
;
④在
轴上找一点
,使
的和最小,则最小值为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eaa6bb3c2d6a6db9658f52fb35057b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://img.xkw.com/dksih/QBM/2023/1/15/3153561642450944/3238784995942400/STEM/e7f5a4bb23eb452ca1d0e3d8fbf4f8f9.png?resizew=154)
①抛物线与直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a58e8e0a68144ece53ae60accd29bfac.png)
②若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b651989ce39b9ed269f99ff43f727a39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dab37d5b3dbcf13e1040f0624a77efda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dace5ee36994310532f4953fd85e9b4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4fc27fbec0c51f6320b9bbdb091e6a.png)
③将该抛物线先向左,再向下均平移
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05caa0438933fc95fc18ab490c5285f8.png)
④在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26653bd5af141d22514807c7db94b3f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2b13f1775ead368b649a825866f5e33.png)
A.①②④ | B.①②③ | C.①③④ | D.②③④ |
您最近一年使用:0次
名校
9 . 关于
的二次函数
,甲同认为:若
,则当
时,
随
的增大而增大,乙同学认为:若该二次函数的图象在
轴上截得的线段长为3,则
的值是1或
,以下对两位同学的看法判断正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a316a6f3de66ecd62f8b56af6cf40ea1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7114eb2305af5e5d426db9ece3fbbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a79d7f73b6128650bf7aed538260c72.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/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/feab93da829a3c07a98ed41b4707967e.png)
A.甲、乙都错误 | B.甲、乙都正确 | C.甲正确、乙错误 | D.甲错误、乙正确 |
您最近一年使用:0次
名校
10 . 我们约定[a,
b,c]为二次函数
的“相关数”.
【特例感知】
“相关数”为[1,4,3]的二次函数的解析式为
,
“相关数”为[2,5,3]的二次函数的解析式为
;
“相关数”为[3,6,3]的二次函数的解析式为
;
(1)下列结论正确的是____________(填序号).
①抛物线
,
,
都经过点
;
②抛物线
,
,
与直线
都有两个交点;
③抛物线
,
,
有两个交点.
【形成概念】
把满足“相关数”为[n,n+3,3](n为正整数)的抛物线
称为“一簇抛物线”,分别记为
,
,
,…,
.抛物线
与
轴的交点为
,
.
【探究问题】
(2)①“—簇抛物线”
,
,
,…,
都经过两个定点,这两个定点的坐标分别为 .
②拋物线
的顶点为
,是否存在正整数
,使![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
是直角三角形?若存在,请求出
的值;若不存在,请说明理由.
③当
时,抛物线
与
轴的左交点
,与直线
的一个交点为
,且点
不在
轴上.判断
和
是否相等,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b700fa9aeb1016aa71f76e4b6bb212e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8352b2e643a7ce605334f1b0e572bfb0.png)
【特例感知】
“相关数”为[1,4,3]的二次函数的解析式为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a32d30dc00f0bac2ac24ac33155e02bb.png)
“相关数”为[2,5,3]的二次函数的解析式为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75e5b1a32d2e99834090d5bb4c054425.png)
“相关数”为[3,6,3]的二次函数的解析式为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51a97bee8fd4e9671fc85fe26c70fa6b.png)
(1)下列结论正确的是____________(填序号).
①抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54015ff5b49e3283901da1291b6b921d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9314bd1d7a6e070f4f2428f9a321804e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb0e705301752424a492f6277ed7774e.png)
②抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54015ff5b49e3283901da1291b6b921d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9314bd1d7a6e070f4f2428f9a321804e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9355031ea0b2dc9cef3777621bc6d38.png)
③抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54015ff5b49e3283901da1291b6b921d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9314bd1d7a6e070f4f2428f9a321804e.png)
【形成概念】
把满足“相关数”为[n,n+3,3](n为正整数)的抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79b9eaa5e7ab7a1e5c512b571914dc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54015ff5b49e3283901da1291b6b921d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9314bd1d7a6e070f4f2428f9a321804e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79b9eaa5e7ab7a1e5c512b571914dc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79b9eaa5e7ab7a1e5c512b571914dc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cfeacc29e6a61c5b3b4e439c0a91df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63f5c583c98a1fd516c6ceaa60b55dec.png)
【探究问题】
(2)①“—簇抛物线”
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54015ff5b49e3283901da1291b6b921d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f6872ffb1934339c53c2c2282d5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9314bd1d7a6e070f4f2428f9a321804e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79b9eaa5e7ab7a1e5c512b571914dc8.png)
②拋物线
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③当
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