1 . 对于抛物线
,我们发现其图像上任意一点到点
的距离和到直线
的距离总是相等,于是规定点
为抛物线的焦点,直线
为抛物线的准线.
例如:如图
,
,其焦点为
,准线为直线
,抛物线上任意一点
到准线的距离为
,则
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7c498fef371d208d0494781144d75a.png)
,即
;同理可得
时,
也成立.利用焦点和准线的性质解决下列问题:
的焦点和准线;
(2)如图
,已知抛物线
的焦点为
,其准线与
轴交于点
,过焦点
的直线与抛物线交于
两点,求证:
;
(3)已知抛物线
,焦点为
,点
为对称轴右侧的抛物线上一点,
且
,
①求
的值;
②过焦点
的直线与该抛物线交于
两点,
为抛物线准线上一点,当
为等边三角形时,求直线
的解析式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f257f6b86030d866857d10ec433ef75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce43981e5251e382690797f24907de2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2af31a8d791f28399fc13be3250136dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce43981e5251e382690797f24907de2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2af31a8d791f28399fc13be3250136dc.png)
例如:如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dcc5c8d58dfa320ba55357e41264835.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c6991563453cd366d99513c393d1ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2af31a8d791f28399fc13be3250136dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44ee82573986d4fa6a7ee1b5f397edae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35d58f9019097bd05037aefd5c322916.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9008681dcd66e81c4522752bdac78738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7c498fef371d208d0494781144d75a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7737f5fea52d07a57541a93ea717f9ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1c5fadd549fc5f6c685baba575a3db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e10e1c43b86a8cd4360ca9b57232164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1c5fadd549fc5f6c685baba575a3db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e48f28aeccf369df5980ac787e9e313f.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d73e44af07b6d5fa478ce4bef18836bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6f48b9a53c0155a692509cf31f7e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f290023b1a8651d4a4c110bf7c4bab33.png)
(3)已知抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c1d6564041aa10021afaeee8539118c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a0dd5fbc60c15aebf71d23765f804d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65704d24c9ba7271d59833f675be553e.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
②过焦点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f44755c5fee4b90266eac73ad47a128.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ed4c4e8edbd179f3fc38a6653f18c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
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2 . 问题提出
如图,在矩形
中,
,
.在
上取一点
,
,点
是
边上的一个动点,以
为一边作四边形
,使点
落在
边上,点
落在矩形
内或其边上.
是正方形时,
的长为______,
的面积为______;
(2)如图②,当四边形
是菱形时,若
,
的面积为
.求
与
之间的函数关系式;
问题解决
(3)如图③,正方形
是某小区旁一块边长为100米的空地,为了提升附近居民的生活环境,现要把这块空地及其周边打造成一个生态公园.按设计要求,
为广场区域,正方形
是休息区,
是儿童娱乐区,
,点
在
边的延长线上,为满足各区域及绿化用地,想让广场的面积尽可能小.请问是否存在符合设计要求的面积最小的三角形广场
?若存在,求
面积的最小值及这时点
到点
的距离;若不存在,请说明理由.
如图,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16e0c5cb53fd85b7a23f0580df6bb49a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1364213f546b37f8764ddcb59e36ae4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aba63d391602d0798a1875da35fef40d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aba63d391602d0798a1875da35fef40d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f39f31a107039ce5fdf44f6f33fc3744.png)
(2)如图②,当四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aba63d391602d0798a1875da35fef40d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/617345f55a92ef7e03e11a7f9f174e30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f39f31a107039ce5fdf44f6f33fc3744.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
问题解决
(3)如图③,正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc6ca93d868b56ce9e2f752ec264eabb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9206d36ef2bce6e6bfce5669f0fb6d18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daee8baa62b5b8d5db41eab0d360ee51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bbed195d680cddc98a64e3d8258e6d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc6ca93d868b56ce9e2f752ec264eabb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
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真题
3 . 九(1)班劳动实践基地内有一块面积足够大的平整空地.地上两段围墙
于点O(如图),其中
上的
段围墙空缺.同学们测得
m,
m,
m,
m,
m.班长买来可切断的围栏
m,准备利用已有围墙,围出一块封闭的矩形菜地,则该菜地最大面积是________
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a77e3c1c236141d6118429fade0a9b9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90c780dac29ff8b7df5881d3b33abab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddd6b3eb12643fe82e40ba73c02c2a8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd08edcc9ac46efd5bea7190c1e3c5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55e2857963e3ea3578e9a13638c3a2c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f42f56b246c0eecf454c6ca8f956fb04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78691dacfa00dd2448b1ba94b264ec8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c748e40ba21ac5063d3bccaa57ef278.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ce13774b09ff2edddaf21a072cf60a.png)
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4 . 阅读与思考
下面是小勇同学的数学日记,请仔细阅读并完成相应的任务.
(1)当
_________
时,无盖长方体储物箱的容积最大,最大值为________![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc6d1d99afa158b4ba4fc0dae562fcc1.png)
(2)请你列出S关于x的函数表达式,并根据实际意义直接写出x的取值范围.
(3)在解决问题的过程中,你获得什么启示?(写出一条日记中所体现的数学观点即可)
下面是小勇同学的数学日记,请仔细阅读并完成相应的任务.
×年×月×日星期六 “用函数思想解决生活中的实际问题” 爸爸计划利用一张如图1所示的 ![]() 如图1,在纸板的四个角上分别剪去一个同样大小的正方形,再沿虚线折叠得到如图2所示的无盖长方体储物箱.设四个角上分别剪去的正方形的边长为 ![]() ![]() |
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc6d1d99afa158b4ba4fc0dae562fcc1.png)
(2)请你列出S关于x的函数表达式,并根据实际意义直接写出x的取值范围.
(3)在解决问题的过程中,你获得什么启示?(写出一条日记中所体现的数学观点即可)
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5 . 如图, 等边
的边长为
, D是
上一点,过D作
的垂线,与
的另一边交于点E,设线段
的长度为
,
的面积为
,则s关于x的函数图象大致为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a67f966f8f6705ca3a8916959386eaab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c548f38ec12518ec8afa3ef52a2d3bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefe4a3e7a7fa195ed6a6712447639b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/566e7718084ec31f7213375b28509b55.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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6 . 已知点D与点
,
,
,是一平行四边形的四个顶点,则
的最小值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bc3341314fc6ce2699f31471021df53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a9f2236fefba74e611fe8674c24c0c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/330783720bdbdcddbadeae8bbab5f676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
A.10 | B.![]() | C.![]() | D.9 |
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7 . 【综合与实践】数学来源于生活,同时数学也服务于生活.
【知识背景】如图,校园中有两面直角围墙,墙角内的
处有一棵古树与墙
的距离分别是
和
,在美化校园的活动中,某数学兴趣小组想借助围墙(两边足够长),用
长的篱笆围成一个矩形花园
(篱笆只围
两边),设
.
【方案设计】设计一个矩形花园,使之面积最大,且要将这棵古树
围在花园内(含边界,不考虑树的粗细).
【解决问题】思路:把矩形
的面积
与边长
(即
的长)的函数解析式求出,并利用函数的性质来求面积的最大值即可.
的代数式表示
的长;
(2)花园的面积能否为
?若能,求出
的值;若不能,请说明理由:
(3)求面积
与
的函数解析式,写出
的取值范围;并求当
为何值时,花园面积
最大?
【知识背景】如图,校园中有两面直角围墙,墙角内的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5898ecbb5c528fa6cd5844d2133eb270.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e685c2fe2f54fa7947538472cd7caa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e17ee14bd91bfff409c06fd434f6745.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf2fc57da7f8399eae9ad9ad22ca836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66ac400e3f5ba8b945bbef83db8611b7.png)
【方案设计】设计一个矩形花园,使之面积最大,且要将这棵古树
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
【解决问题】思路:把矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)花园的面积能否为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdb92c9032804326713c7b4feea53f40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(3)求面积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.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/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
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8 . 习近平总书记强调:“要教育孩子们从小热爱劳动、热爱创造”.某校为促进学生全面发展、健康成长,计划在校园围墙内围建一个矩形劳动实践基地,其中一边靠墙(如图),另外三边用长为30m的篱笆围成.已知墙长为18m,设这个矩形劳动实践基地垂直于墙的一边的长为
,平行于墙的一边的长为
,矩形劳动实践基地的面积为
.
(2)能否围成一个
的矩形劳动实践基地,若能,请求出此时垂直于墙的一边的长;若不能,请说明理由.
(3)若根据实际情况,可利用的墙的长度不超过14m,垂直于墙的一边长为多少时,这个矩形劳动实践基地的面积最大?并求出这个最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06d184f66d90d46f4393f24cc2218091.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b4ad3541431e119b4d478446f0f170c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baaa2d65026770c5505f8adeb450e43b.png)
(2)能否围成一个
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6711f79513b534982a9ada2b625e9fdd.png)
(3)若根据实际情况,可利用的墙的长度不超过14m,垂直于墙的一边长为多少时,这个矩形劳动实践基地的面积最大?并求出这个最大值.
您最近一年使用:0次
9 . 在直角坐标平面中,O为坐标原点,抛物线
,L关于x轴对称的抛物线
的图象经过点
与点![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e96bb35b56efb9d86953473ab5cdd94e.png)
(1)求抛物线
的表达式;
(2)点D在抛物线
的对称轴上,连接
,
,
与
的对称轴交于B点,若
与
相似,求点D的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23a8fc42c79d1c76fb9219e6205c5ad4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf90af48c665ee801c05cc55914b8fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/993769b494e12c21dff0ee7c53a4a49f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e96bb35b56efb9d86953473ab5cdd94e.png)
(1)求抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf90af48c665ee801c05cc55914b8fd.png)
(2)点D在抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf90af48c665ee801c05cc55914b8fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf90af48c665ee801c05cc55914b8fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73636989e83905f8800a865c2b608c43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bbf9680f74a9ac5d934304654ce2771.png)
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名校
10 . 如图,要用篱笆(虚线部分)围成一个矩形苗圃
,其中两边靠的墙足够长,中间用平行
的篱笆
隔开,已知篱笆的总长度为18米.
的一边
的长为
,矩形苗圃
面积为
,求
关于
的函数关系式,直接写出自变量
的取值范围;
(2)当
为何值时,所围矩形苗圃
的面积为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df149da97eaa1ee5f3a793ddf33af124.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82b5b42b96d69524fdd0ed52dde8e890.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)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86edef9c6f9c528ee29e408538dd864e.png)
您最近一年使用:0次