1 . 已知
是
的正比例函数,且当
时,
.
(1)求
与
之间的函数关系式;
(2)当
时,求
的最大值.
![](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/639c3d2ff5ee566fcc1b69c65712a661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9355031ea0b2dc9cef3777621bc6d38.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a417f68c6538bfb63e729c047755b4ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
您最近一年使用:0次
2022-08-21更新
|
124次组卷
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2卷引用:广西壮族自治区贵港市港北区港北区第六初级中学2022-2023学年八年级下学期5月月考数学试题
2 . 如图,在平面直角坐标系
中,已知一次函数
的图象与y轴交于点A、与x轴交于点B,以点A为直角顶点构造等腰直角
,点C在
的左侧.
(1)已知点B是x轴正半轴上一点,若
.
①求
的长度;
②求经过点C的正比例函数解析式;
(2)当点B在x轴上运动时,连接
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65920f4695a14c85e7085450aee08b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/2/a1153033-7115-4d45-b9a4-28f26410b37b.jpg?resizew=191)
(1)已知点B是x轴正半轴上一点,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3b136c45d114d9432aa492909cda4f2.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
②求经过点C的正比例函数解析式;
(2)当点B在x轴上运动时,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2b199851e9d67f509b177176ae4359e.png)
您最近一年使用:0次
3 . 已知
与
成正比例,且
时,
.
(1)求
关于
的函数关系式;
(2)请在图中画出该函数的图象;
(3)已知
,
为(2)中图象上的动点,
是
轴上的动点,连接
,
,则
的最小值为________.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3aa4b75097df3ab299704d9e5b5fdf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39cc033406da2cdd342308972c6701f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29372c1805b89e56d45d21351fcab21d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/6/94722423-6fb4-488d-8c42-197bb9a5eeb1.png?resizew=294)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)请在图中画出该函数的图象;
(3)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/774480361088aa3198c7bc3148fa23fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.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/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84d454c82d9e52747563d47b68099249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d5d33d9428db40a0d2b4addc61538ef.png)
您最近一年使用:0次
2023-09-04更新
|
207次组卷
|
4卷引用:江苏省南通市崇川区启秀中学2022-2023学年八年级下学期第一次月考数学试题
江苏省南通市崇川区启秀中学2022-2023学年八年级下学期第一次月考数学试题(已下线)专题6.31 一次函数(全章分层练习)(基础练)-2023-2024学年八年级数学上册基础知识专项突破讲与练(苏科版)(已下线)专题4.25 一次函数(全章分层练习)(基础练)-2023-2024学年八年级数学上册基础知识专项突破讲与练(北师大版)(已下线)专题19一次函数的图像(3个知识点5种题型3个中考考点)-【帮课堂】2023-2024学年八年级数学上册同步学与练(苏科版)
4 . 阅读下列材料:
对于任意正实数a、b,
∵
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d06a4f80a445d66d72facb4254b78960.png)
当且仅当
时,等号成立.
结论:在
均为正实数)中,若
为定值
则
当且仅当
时,a+b有最小值
.
拓展:对于任意正实数
,都有
当且仅当
时,等号成立.
在
(a、b、c均为正实数)中,若
为定值
,则
当且仅当
时,
有最小值![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d39230881f927575624e7c6e26391d.png)
例如:
则
,当且仅当
,即
时等号成立.
又如:若
求
的最小值时,因为
当且仅当
,即
时等号成立,故当
时,
有最小值
.
根据上述材料,解答下列问题:
(1)若a为正数,则当a=______时,代数式
取得最小值,最小值为_____;
(2)已知函数
与函数
,求函数
的最小值及此时
的值;
(3)我国某大型空载机的一次空载运输成本包含三部分:一是基本运输费用,共8100元;二是飞行耗油,每一百公里1200元;三是飞行报耗费用,飞行报耗费用与路程(单位:百公里)的平方成正比,比例系数为0.04,设该空载机的运输路程为
百公里,则该空载机平均每一百公里的运输成本
最低为多少?
对于任意正实数a、b,
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98dd6a6e9b630c87bb57e50e17771233.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d06a4f80a445d66d72facb4254b78960.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6aa7af3359c9799e138292564244e85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
结论:在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a483fb4ec33ae214a7fd27ed318d097e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18f0281e6bbdbe08beeccb55adf84536.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aac95e741a0cda29e2e907e4f114d2e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9473c9b73a6edaba66ad684b1d098d1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280f7cc99fa100b85cc7a133811a9a8d.png)
拓展:对于任意正实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ace74bfb716753490ebe0e740ff5baa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8972866f40a8fd668ec7faac5c2332a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44acc0ee22dc4b7750e8be825e7c1355.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8972866f40a8fd668ec7faac5c2332a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d2d7ddd7ef3b6cde30018bc6a84b9e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/506a3d948d91e923b3e884157945f6cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44acc0ee22dc4b7750e8be825e7c1355.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ae24688d4c45aad43e9af0b7bbfda6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d39230881f927575624e7c6e26391d.png)
例如:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b366bd12b731cfa3dda3a8b86d10f194.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01cdc65f1068c9506046926a7724254e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f1e3048c60441505af80599dba214f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/707ea658f3a9359f5740d5aab48f7948.png)
又如:若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b366bd12b731cfa3dda3a8b86d10f194.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ec68b7a1bf1d8b9e4dc84d218b7b836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82db9ccbc773211b64e4a675d00b4517.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/182e0b249333a0a9d66a4b3a44d63d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/707ea658f3a9359f5740d5aab48f7948.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/707ea658f3a9359f5740d5aab48f7948.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ec68b7a1bf1d8b9e4dc84d218b7b836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
根据上述材料,解答下列问题:
(1)若a为正数,则当a=______时,代数式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a589cfa1be20200ed313275bd8ddf5b9.png)
(2)已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f322df5a430eb7b1b176a68309e7601.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7bf03919ea7547d92f9640ec65fce84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d6e75677951ef1388f76aee5a779149.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(3)我国某大型空载机的一次空载运输成本包含三部分:一是基本运输费用,共8100元;二是飞行耗油,每一百公里1200元;三是飞行报耗费用,飞行报耗费用与路程(单位:百公里)的平方成正比,比例系数为0.04,设该空载机的运输路程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
您最近一年使用:0次
2020-05-06更新
|
312次组卷
|
2卷引用:重庆八中2019- 2020学年九年级下学期月考数学试题