综合与实践
【项目学习】
配方法是数学中重要的一种思想方法,利用配方法可求一元二次方程的根,也可以求二次函数的顶点坐标等.所谓配方法是指将一个式子的某部分通过恒等变形化为完全平方式或几个完全平方式的和的方法.其实这种方法还经常被用到代数式的变形中,并结合非负数的意义解决某些问题.
例1:把代数式
进行配方.
解:原式
.
例2:求代数式
的最大值.
解:原式
.
,
,
,
的最大值为
.
【问题解决】
(1)若
满足
,求
的值.
(2)若等腰
的三边长
均为整数,且满足
,求
的周长.
(3)如图,这是美国总统加菲尔德证明勾股定理的一个图形,其中
是
和
的三边长,根据勾股定理可得
,我们把关于
的一元二次方程
称为“勾系一元二次方程”.已知实数
满足等式
,且
的最小值是“勾系一元二次方程”
的一个根.四边形
的周长为
,试求
的面积.
【项目学习】
配方法是数学中重要的一种思想方法,利用配方法可求一元二次方程的根,也可以求二次函数的顶点坐标等.所谓配方法是指将一个式子的某部分通过恒等变形化为完全平方式或几个完全平方式的和的方法.其实这种方法还经常被用到代数式的变形中,并结合非负数的意义解决某些问题.
例1:把代数式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23599f004413ab4994d19ac75ae70ff4.png)
解:原式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/def29394eccd0185b201ddb7bfc15a1a.png)
例2:求代数式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd48ebb86678892dc1c5f5cda100ce8e.png)
解:原式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6abc808dcece926aacb2b8cbf8f3650b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7bff66e408ce644cfc314f962c1c23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e26bf0454185d73491287275c64ebac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6012695248afd0bcc3fdf780d9395339.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ae7f7353ee10e85813279845ac63f81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81fb134b2b48acc99213fff6ccfee65f.png)
【问题解决】
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f72e503fe4b599f68bf2e9926f4bee90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06af392cba591a8cdf46c45663220b7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16ea71627996f5897113e72f955d0487.png)
(2)若等腰
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88f2599ca8b6b683e57a82699c8b1ebb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/216aadc35e34cbf32eeedf765dd3ceab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(3)如图,这是美国总统加菲尔德证明勾股定理的一个图形,其中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88f2599ca8b6b683e57a82699c8b1ebb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f73fbc2f33d3402cd96a776a376d9835.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00d79ed65d90dfd96ae02250d6c94b85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98f97e109bcafdf2d9079cdcd7ec190a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d523eca6a54d7b01e7b9997735d38b95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f65a8964437faf24f5ed67c57f8fa79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaacfaef44a654c0a1c283ef03fc0550.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98f97e109bcafdf2d9079cdcd7ec190a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b9d54cbbf601f4583659771eb534997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ec978eb43bc4f9e7df83b0d0195dcda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
更新时间:2023-09-28 08:44:16
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相似题推荐
解答题-问答题
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【推荐2】已知二次函数
(
为实数),记顶点为
.
(1)直接写出
点坐标(用
的代数式表示);
(2)记该函数图像与
轴交于点
,直线
与
轴所夹的角为
,当
时,求
的值;
(3)若该二次函数的图像经过点
、
,记
,当
时,试探究
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c38f4b2c33af074f2fd21c4529d0eb9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a550c916c64f621010e604a30ef67566.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
(1)直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a550c916c64f621010e604a30ef67566.png)
(2)记该函数图像与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b39addc1173a458af87ed5c5e3f06466.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9fc5f31608eeddfc28b69300d91b4e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaacfaef44a654c0a1c283ef03fc0550.png)
(3)若该二次函数的图像经过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4a90cfdbfa05577b6ec0b22739e7c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b91ab4021fbd72b6758c37b599ea74df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec425f3d26fb511177895af4a7e38b71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/945c33b7146b45bc1077bdd48b53fcb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91edc7e2d4811f5ea6c01284cf00393a.png)
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【推荐1】在学习《完全平方公式》时,某数学学习小组发现:已知
,
,可以在不求
、
的值的情况下,求出
的值.具体做法如下:
.
(1)若
,则
______;
(2)若
满足
,求
的值,同样可以应用上述方法解决问题.具体操作如下:
解:设
,
,
则
,
,
所以
.
请参照上述方法解决下列问题:若
,求
的值;
(3)如图,某校“园艺”社团在三面靠墙的空地上,用长12米的篱笆(不含墙
)围成一个长方形花圃ABCD,花圃ABCD的面积为20平方米,其中墙AD足够长,墙
墙AD,墙
墙AD,
米.随着学校“园艺”社团成员的增加,学校在花圃
旁分别以
边向外各扩建两个正方形花圃,以
边向外扩建一个正方形花圃(如图所示虚线区域部分),请问新扩建花圃的总面积为______平方米.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ff7e62312dbd1cd5b50a6dc7fdfc166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c03256f5374101853665aa4c1934e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c925be255ca736a53b24d13ddede1a86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f58eaa00cb087f91ca94153e0bb853cc.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8aa445f396a7b282ceec66626651b13e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2b1b96f5050de3bc7ae53c7bf0c21e8.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/254ba46b36a822c07e674fd2cef2ff1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbcdd0cbbe1dd69def5e464e23c7ea11.png)
解:设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9eec6b5dece5549079b1adeba235c4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25c51598590677496d783975a45e3c25.png)
则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f7bb1b876e04d83bf52684c44d95193.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70d07ce38063ac9320be2aeb1399e507.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dca3cf81df88ebe925e433ff4dab7b51.png)
请参照上述方法解决下列问题:若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29a5b08e510e00115a02cbf034ae3a27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727f4ad503f911252d176aa8706beecf.png)
(3)如图,某校“园艺”社团在三面靠墙的空地上,用长12米的篱笆(不含墙
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2064ab2d84cddb36560dcaadd1c69bdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0edb1508fc95765f3bb316bcb5252d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/835766bda2c74b980454f83f3be8e5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05b31d46f66f8bc9e5789c9d134f6b87.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdcf86f7cf381c563ad80af86feeed83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/13/50771a0c-581d-474e-b0a4-e32d604dd21c.png?resizew=222)
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【推荐2】计算下列各式:
(1) 2022+202×196+982
(2) (3x-y)2-(3x+2y)(3x-2y)
(1) 2022+202×196+982
(2) (3x-y)2-(3x+2y)(3x-2y)
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名校
【推荐1】已知抛物线
.
(1)如图1,当
时,抛物线分别交
轴于
两点(点
在点
的左侧),交
轴于点
.
①求出直线
的解析式;
②点
在直线
上方的抛物线上,作
轴,交线段
于点
,作
轴,交抛物线于另一点
,若
,求点
的横坐标;
![](https://img.xkw.com/dksih/QBM/2022/4/8/2958860541411328/2992739383435264/STEM/9f3f0bf2-3893-4f31-8d46-a29e5b1b2a80.png?resizew=198)
(2)如图2,若抛物线与
轴有唯一公共点
,直线
与抛物线交于
两点(点
在点
的左边),直线
轴,交直线
于点
,且点
的纵坐标为4,求证:直线
过定点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c4a23061ba557e2595c7161487ddf90.png)
(1)如图1,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e0569f493435d64509124f84dc671a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.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/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
①求出直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
②点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70b32f59522eea44b24cdd4c2bc0406e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf0215fcd72572bb524eca8a7fdc3f4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30bfc6b5683ec1919f8257765ce056b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://img.xkw.com/dksih/QBM/2022/4/8/2958860541411328/2992739383435264/STEM/9f3f0bf2-3893-4f31-8d46-a29e5b1b2a80.png?resizew=198)
(2)如图2,若抛物线与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af13c88123269e86593b9a8031b4b5cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47a5926f60339afee638ac1429b8762b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57817a3d7b29e095762b0962a25a5c4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/360496a4f5cc8a5faca5e089ae4f9531.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://img.xkw.com/dksih/QBM/2022/4/8/2958860541411328/2992739383435264/STEM/ae233039-468c-4f01-911e-69e58f198fcc.png?resizew=225)
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【推荐2】阅读下面内容:我们已经学习了《二次根式》和《乘法公式》,聪明的你可以发现:当
,
时,∵
,∴
,当且仅当
时取等号.请利用上述结论解决以下问题:
(1)当
时,则
的最小值为______;
(2))若
,求y的最小值.
(3)如图,四边形
的对角线
相交于点O,
、
的面积分别为4和9,求四边形
面积的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67ca5fd57c2c2fcc3c7a574fdd1467d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81674299ac42ad9377ae19b5d336b7a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/759c09917e5728d75bf5cfdb5b4a807f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13f40c24c64bbb0645fcf585f4e66872.png)
(2))若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b77c147b71e33dd52827d5f90f8dbfd.png)
(3)如图,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/989c75a3fd02e4971cab421c88de92f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866b81a8384cce4f24867baca2e6820c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a9a6eeeebf3cff569578d7366b755aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/23/29640fba-0aba-4af1-bdf8-a2779e7e2af5.png?resizew=124)
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【推荐1】【初步感知】
(1)已知,在
中,
,如图1,将边
,
同时绕着点
分别按逆时针、顺时针方向旋转
,得
、
,连接
,
,求证:
;
【类比探究】
(2)如图2,在
,
,若
,
,将边
绕着点A逆时针旋转
,得
,连接
,求
的长.
【拓展应用】
(3)如图3,在平面直角坐标系
中,点
为第二象限内一点,且
,点
坐标为
,若将边
绕点
逆时针旋转
得
,点
恰好在
轴上,将边
绕点
顺时针旋转
得
,求点
坐标.
(1)已知,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0efc7b22d85ff04a0ac89743f0bea1f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/421291381be28da4bd16560fd383b4a9.png)
【类比探究】
(2)如图2,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
【拓展应用】
(3)如图3,在平面直角坐标系
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01cd2bf7c88e24c91625e0f20ba2a4bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f809aef106f5da271c4800b261a628f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/29/3d1efe07-5b89-4cb2-af38-92de89d6b2a4.png?resizew=475)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
名校
【推荐2】如图,在
中,
,
,点
在直线
上,点
在直线
上,连接
、
,且
,直线
交
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/24/20bf0109-cee7-4bc8-bae6-6f9590931485.png?resizew=469)
(1)如图1,当点
在线段
上时,
,
,求BE的长;
(2)如图2,当点
是
的中点时,求证:
;
(3)如图3,连接
,将
沿着
翻折,得到
,点
是
上一点,且
,当
最短时,请直接写出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba11242dcc61d3c7c3555b598b5fdc89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/24/20bf0109-cee7-4bc8-bae6-6f9590931485.png?resizew=469)
(1)如图1,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a88c44f558705de3bcefcfc0ece96b8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
(2)如图2,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e02b9554e2e8515bb14eb863e48c9cfe.png)
(3)如图3,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ac5396c5ea442e0364b50c1db3d2da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/172f1b400d9ddec4ea01f6fd040b3802.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/085e70c258727bd4461e4535b218c2bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42198b8e646ccfbbec323fd364c4d90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ef7d8f1ce495aa3b9045a0deab7e808.png)
您最近一年使用:0次