名校
1 . 《见微知著》谈到:从一个简单的经典问题出发,从特殊到一般,由简单到复杂:从部分到整体,由低维到高维,知识与方法上的类比是探索发展的重要途径,是思想阀门发现新问题、新结论的重要方法.
阅读材料一:利用整体思想解题,运用代数式的恒等变形,使不少依照常规思路难以解决的问题找到简便解决方法,常用的途径有:(1)整体观察;(2)整体设元;(3)整体代入;(4)整体求和等.
例如,
,求证:
.
证明:原式
.
波利亚在《怎样解题》中指出:“当你找到第一个藤菇或作出第一个发现后,再四处看看,他们总是成群生长”类似问题,我们有更多的式子满足以上特征.
阅读材料二:基本不等式
,当且仅当
时等号成立,它是解决最值问题的有力工具.
例如:在
的条件下,当x为何值时,
有最小值,最小值是多少?
解:∵
,∴
,即
,∴
,当且仅当
,即
时,
有最小值,最小值为2.
请根据阅读材料解答下列问题
(1)已知如
,求下列各式的值:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f0dd92f322200ecabfb74ffd7cf3f4a.png)
___________ .
(2)若正数
满足
,则
的最小值为___________ .
阅读材料一:利用整体思想解题,运用代数式的恒等变形,使不少依照常规思路难以解决的问题找到简便解决方法,常用的途径有:(1)整体观察;(2)整体设元;(3)整体代入;(4)整体求和等.
例如,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca27cc54ca0332245f5167488daa3408.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e2764ccd2cfe6de0c53dce98e45b120.png)
证明:原式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87898da3367d13667477a10c9cc47ac2.png)
波利亚在《怎样解题》中指出:“当你找到第一个藤菇或作出第一个发现后,再四处看看,他们总是成群生长”类似问题,我们有更多的式子满足以上特征.
阅读材料二:基本不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a28514741f365301978e922fdca0fcc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
例如:在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13f40c24c64bbb0645fcf585f4e66872.png)
解:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c42b50f6f9e56ea5f222b0a40cb4a3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91bb4a7110c19cd10cb915e55438314b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d32ba3941cef6b1d549f050f0d314e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63af71b9e6f71cd26e6e97541154cd8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b6a593ef3641dbd11e324dbe78b4dc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13f40c24c64bbb0645fcf585f4e66872.png)
请根据阅读材料解答下列问题
(1)已知如
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca27cc54ca0332245f5167488daa3408.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f0dd92f322200ecabfb74ffd7cf3f4a.png)
(2)若正数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca27cc54ca0332245f5167488daa3408.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ab1cbf887eca130c254f6e0cf3fdb2f.png)
您最近一年使用:0次
2 . 小明在学习矩形时发现:在矩形
中,点
是
边上一点,过点
作
交边
于点
,若
,则
平分
.他的证明思路是:利用矩形的性质得三角形全等,再利用边角转化使问题得以解决.请根据小明的思路完成以下作图与填空.
(1)用直尺和圆规,过点
作
的垂线交
于点
;(只保留作图痕迹)
(2)已知:如图,在矩形
中,点
是
边上一点,过点
作
交边
于点
.求证:
平分
;
证明:
四边形
是矩形,
,
①_________________
.
,
,
,
②_________________.
又
,③_________________,
④_________________
.
.
又
,
,
.
⑤_________________,
.
.
平分
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/992a19339adac3a2f1aab1fbc11b1c68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f805768a5ffaf8bdfa4bc3b680aafdc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3981e7286d41960daf4e110c1c84e03a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/6/9eb8f234-3821-48d3-8637-3cca31a02ef7.png?resizew=155)
(1)用直尺和圆规,过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
(2)已知:如图,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/992a19339adac3a2f1aab1fbc11b1c68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b48e4874d9f210d8ce6ee784a47e8588.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3981e7286d41960daf4e110c1c84e03a.png)
证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f3d198e76391779fa3badc848c8ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deeeb5318d4077995233dabb715f854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c515a84858c394146ed2ca984916cdf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83873a9d782f2588c5eedbfe73f9bc2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/587aa905348cc7cd1333e7472a57430a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f95cf1631aee3f6b55b0435e1da9442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00d80f47b98c1b4bc66cc0bc86c2cd2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2de0d10ef8b748d4531250c37c5d3f9e.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df7a0621aafbc7e55cd6f6b9686c214b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a755b788551f0f6d022f1b6ba557dd8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b68af712817ab23370b394227723e61a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a54012359305f6200e9811a4e03ab3f.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e9dd6147fd83173b71cc7467e481b3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0091d0711859cb2c619b8c3846c44051.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9287a2c4832bc0c48c9768acc6aa5ccc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f3d198e76391779fa3badc848c8ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14f4108d0dfb537295bbd3f08b407be3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18184310094795a3abb3a09974ab8b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6911a6519903fb7e464ab74e873996a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3981e7286d41960daf4e110c1c84e03a.png)
您最近一年使用:0次
名校
3 . 如图,在正方形ABCD的对角线AC上取一点E,使得
,连接BE.
(1)证明:
;
(2)延长BE至F,使
,连接CF,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c239a56587c675b532347546b48ea09a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/28/f902101f-244a-446d-a4d8-e0d24c1cce53.png?resizew=160)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba11242dcc61d3c7c3555b598b5fdc89.png)
(2)延长BE至F,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d197ea8c1c8bbdf5edade431388eb713.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3a2d014899fa3341b58348530f3d98.png)
您最近一年使用:0次
4 . 《几何原本》是古希腊数学家欧几里得得所著的一部数学著作,在《几何原本》第六卷给出了内角平分线定理,其内容为:在一个三角形中,三角形一个内角的角平分线内分对边所成的两条线段,与这个角的两邻边对应成比例.例如,在
中(图1),
为
的平分线,则有
.
(2)如图2,已知
的重心为
,内心为
,若
的连线
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/608bf0cfbbe809837adec2755fcd2901.png)
(2)如图2,已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e105760638b22b26ff8bec4354255e4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57b8fc74eea80b1ccf11d16ad7b3178a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/981b01ddc1aa5fcf155ad41307d22b17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a94a70686cb9c91ec9705bed47dc663.png)
您最近一年使用:0次
5 . 已知:如图,等腰三角形
中,
,
,直线
经过点
(点
、
都在直线
的同侧),
,
,垂足分别为
、
.
(1)求证:
;
(2)请判断
、
、
三条线段之间有怎样的数量关系,并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.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/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e13b505788d3d02bf232ac637fc3a8ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e72d26eae9a5470ac982541c609b109.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/21/b7efb7d9-2f61-428f-9220-09f39fa06f0b.png?resizew=172)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33e9e5200fe1aed46fc8dc8fcdd916d5.png)
(2)请判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
您最近一年使用:0次
名校
6 . 如图,在正方形ABCD中,
.求证:
.
证明:设CE与DF交于点O,
∵四边形ABCD是正方形,
∴
,
.
∴
.
∵
,∴
.
∴
.∴
.
∴
.∴
.
某数学兴趣小组在完成了以上解答后,决定对该问题进一步探究
(1)【问题探究】如图1,在正方形ABCD中,点E、F、G、H分别在线段AB、BC、CD、DA上,且
.试猜想
的值,并证明你的猜想.
(2)【知识迁移】如图2,在矩形ABCD中,
,
,点E、F、G、H分别在线段AB、BC、CD、DA上,且
.则
___________.
(3)【拓展应用】如图3,在四边形ABCD中,
,
,
,点E、F分别在线段AB、AD上,且
.求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/783b84ed8d927b77491092f7d2ee2989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf857e03d4320c999d328fd657c2d412.png)
证明:设CE与DF交于点O,
∵四边形ABCD是正方形,
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0973b93383c24af95de98d9cacb2843b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a16dc02090b6e9263555061f14fbc8c.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a0e50d96e967bd909e665070db3d9a4.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/783b84ed8d927b77491092f7d2ee2989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8cc88685997c7586d1d4bf75a055433.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37f8d038a3d35e39ece97f530a324b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd478aa6add1eae126321890a34dde15.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5af9ed02d3b811045d61cffd2b2edf1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf857e03d4320c999d328fd657c2d412.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/16/0a9342c1-2813-4c25-97f8-9a0d42f5ddcf.png?resizew=104)
某数学兴趣小组在完成了以上解答后,决定对该问题进一步探究
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/16/7ea22d00-fa1d-497b-9cc6-4c1c55f886d3.png?resizew=418)
(1)【问题探究】如图1,在正方形ABCD中,点E、F、G、H分别在线段AB、BC、CD、DA上,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846b1b49f05812b0761eb565062d32f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/885a273360456694a3d40a913f3df2fc.png)
(2)【知识迁移】如图2,在矩形ABCD中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa375c3888b332f24e7d0f9b9600c694.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/890aea25780f7ba34adb23e799808462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846b1b49f05812b0761eb565062d32f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d852b8a7e7b287c0bae2ce10d3e6dc1.png)
(3)【拓展应用】如图3,在四边形ABCD中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b377f22aafd3742ad860f77abaacef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6b670ec1599330f6af99c600404afcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ea624cb140001a7e9d7567903a29521.png)
您最近一年使用:0次
名校
解题方法
7 . 如图,在三棱柱
中,若G,H分别是线段AC,DF的中点.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
;
(2)在线段CD上是否存在一点
,使得平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad2c1789c5361169483df2924acd7321.png)
平面BCF,若存在,指出
的具体位置并证明;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e0147945bdf3db4bf5e40be746ef2e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
(2)在线段CD上是否存在一点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad2c1789c5361169483df2924acd7321.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
您最近一年使用:0次
2023-04-13更新
|
3160次组卷
|
9卷引用:浙江省宁波市三锋教研联盟2022-2023学年高一下学期期中联考数学试题
浙江省宁波市三锋教研联盟2022-2023学年高一下学期期中联考数学试题(已下线)立体几何专题:立体几何探索性问题的8种考法(已下线)13.2.4 平面与平面的位置关系 (1)河北定州中学2022-2023学年高一下学期5月月考数学试题江西省宜春市第十中学2024届高二上学期开学检测数学试题新疆阿克苏市实验中学2022-2023学年高一下学期第三次月考数学试题(已下线)8.5.3 平面与平面平行【第三练】“上好三节课,做好三套题“高中数学素养晋级之路(已下线)11.3.3平面与平面平行-同步精品课堂(人教B版2019必修第四册)(已下线)专题突破:空间几何体的动点探究问题-同步题型分类归纳讲与练(人教A版2019必修第二册)
8 . 数学课上,张老师给出这样一个问题:
已知,如图,正方形
中,点
是
边上一点,作射线
,过点
作
于点
,交
的延长线于点
,连接
.求证:
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/04b5384f-9ba9-4f59-8e42-636ddf571a10.png?resizew=238)
(1)小明和小颖根据题中的条件发现:图1中存在和
相等的角,即_________;
(2)在证明结论时,小明和小颖有了不同的思路.
小颖:我受结论中“
”的启发,可在线段
上截取
,再证
….
小明:我受结论中“
”的启发,可构造一个以
为直角边的等腰直角三角形…
请从小明和小颖的思路中任选一种作出辅助线并给出证明;
(3)张老师对问题进行了拓展;如图2,点
,
分别是线段
,
的中点,若
,
,则
的长度为_________.
已知,如图,正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9677deecea626aa6e4078f0b532ba68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735056c174e8dd7906257a2a50a962a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/763b45108308575da2886e15b9aaa409.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/04b5384f-9ba9-4f59-8e42-636ddf571a10.png?resizew=238)
(1)小明和小颖根据题中的条件发现:图1中存在和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79cd9d0d73549e2944578f3513631ce5.png)
(2)在证明结论时,小明和小颖有了不同的思路.
小颖:我受结论中“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f338392e6ff0731afc335ead43df842f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ceed535959a7a57461b0497200f5eb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cebd249e256bf9745fb904035f408408.png)
小明:我受结论中“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd7626a5615d4646ecf6dbffd93693b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
请从小明和小颖的思路中任选一种作出辅助线并给出证明;
(3)张老师对问题进行了拓展;如图2,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82773737609e65dea3c5c67099f1b10d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
您最近一年使用:0次
9 . 如图,在
中,
为
边上一点,
与
分别为
和
的平分线.
![](https://img.xkw.com/dksih/QBM/2022/8/24/3051581032407040/3054416256311296/STEM/432c6f09ddd742e0800436bc37acdea7.png?resizew=265)
(1)判断
是什么三角形,并证明你的结论;
(2)比较
与
的大小;
(3)以
为直径的
交
于点
,连接
与
交于
,若
,
,求证:
,并求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4189a0821a0ffab9dc171ecd279ba442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c42b59b76eafbbe36f13b2daa60132c.png)
![](https://img.xkw.com/dksih/QBM/2022/8/24/3051581032407040/3054416256311296/STEM/432c6f09ddd742e0800436bc37acdea7.png?resizew=265)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af2cc5f8cec8c498aa12c99c04e1c97d.png)
(2)比较
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
(3)以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.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/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf7679c8b4b1e442ce4286d4b0e9c32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29224be6a2381b38bc64b144d26dad26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f364bf9d8b0bfc299e51097b3ca512f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12b092922acd073edfc3a3887822af40.png)
您最近一年使用:0次
10 . 已知
是
的内接三角形,
为
的切线,
为切点,
为直线
上一点,过点
作
的平行线交直线
于点
,交直线
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/29/9977fd52-78ee-4971-ac47-aec1699b50ee.png?resizew=300)
(1)当点
在线段
上时,求证:
;
(2)当点
为线段
延长线上一点时,第(1)题的结论还成立吗?如果成立,请证明,否则说明理由;
(3)若
,求
的半径.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7bf58e5fea1189b33cf55d86335452f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](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/a7bf58e5fea1189b33cf55d86335452f.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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/29/9977fd52-78ee-4971-ac47-aec1699b50ee.png?resizew=300)
(1)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10ec004a08fa1e44677983a09cac00d1.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59ce4fb445ca4eeaf5e0b1f4b76593db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
您最近一年使用:0次