1 . 如图,在矩形
中,
,
,
是
的中点,以
为圆心,在
的下方作半径为3的半圆
,交
于点
,
.
![](https://img.xkw.com/dksih/QBM/2021/4/9/2696182717988864/2700207393177600/STEM/de9f26d1dc0d4810838d590c2ff89e4a.png?resizew=180)
![](https://img.xkw.com/dksih/QBM/2021/4/9/2696182717988864/2700207393177600/STEM/46e1e07a47d04ccfacb14000387d282e.png?resizew=180)
(1)思考:连接
,交半圆
于点
、
,求
的长;
(2)探究:将线段
连带半圆
绕点
顺时针旋转,得到半圆
,设其直径为
,旋转角为
(
);
①设
到直线
的距离为
,当
时,求
的取值范围.
②若半圆
与线段
相切,或半圆
与线段
相切,设切点为
,直接写出
的长.(
,
,
,结果保留
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07140f277a35733d8c97577ccdd4e3ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/2021/4/9/2696182717988864/2700207393177600/STEM/de9f26d1dc0d4810838d590c2ff89e4a.png?resizew=180)
![](https://img.xkw.com/dksih/QBM/2021/4/9/2696182717988864/2700207393177600/STEM/46e1e07a47d04ccfacb14000387d282e.png?resizew=180)
(1)思考:连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
(2)探究:将线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/292337dce2c74ce4ea6d9ec165f51c48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffdf25ad114b388434b1631d1b1edbcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94d6402e3d060dcdeff009dd8258be92.png)
①设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ec6bfed1d158cf90f3389834e366f89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61b7baa33230ca77967848972c2eb116.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
②若半圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/292337dce2c74ce4ea6d9ec165f51c48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/292337dce2c74ce4ea6d9ec165f51c48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51b10651b26f0ad21685c839fec0e151.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7d861461a5ff9d74ae4fd291a4bc8dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0baa06dc4bf6127219ac8a2696d35461.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2460de244598fb1f3de496330eaec133.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86ebba6ed1add0fe647c0226614b9290.png)
您最近一年使用:0次
2 . 综合与实践
问题:如何将物品搬过直角过道?
情境:如图1是一直角过道示意图,
、
为直角顶点,过道宽度都是
.矩形
是某物品经过该过道时的俯视图,宽
为
.
操作:
探究:
(1)如图2,已知
,
.小明求得
后,说:“
,该物品能顺利通过直角过道”.你赞同小明的结论吗?请通过计算说明.
(2)如图3,物品转弯时被卡住(
、
分别在墙面
与
上),若
,求
的长.
(3)请直接写出过道可以通过的物品最大长度,即求
的最大值 .(结果保留根号)
问题:如何将物品搬过直角过道?
情境:如图1是一直角过道示意图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01f8039a874d818f0067ad4dc93bdd33.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/17b514ca29d7d7df3ccc349e7e93e5fc.png)
步骤 | 动作 | 目标 |
1 | 靠边 | 将如图1中矩形![]() ![]() ![]() |
2 | 推移 | 矩形![]() ![]() ![]() ![]() |
3 | 旋转 | 如图2,将矩形![]() ![]() ![]() |
4 | 推移 | 将矩形![]() ![]() |
探究:
(1)如图2,已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08b23df2ba7d1608dfa6e85746bca8e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21acddb5fca88c447a278544e50d9191.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d9905bea101d3cadddcb5837092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e052b0e0525ba5f3b818fabb1ce00635.png)
(2)如图3,物品转弯时被卡住(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/902f97913e1af1e6c793f7edfe6b2114.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea986fdb57aad53ada2f93428f080fac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
(3)请直接写出过道可以通过的物品最大长度,即求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
您最近一年使用:0次
解题方法
3 . 如图1,已知开口向下的抛物线
与
轴交于
两点,与
轴交于点
不小于
.
(1)求点
的坐标(用含
的代数式表示);
(2)求系数
的取值范围;
请你根据自身能力从
或(4)小题中任选-题作答.
(3)如图2,当
时,
为直线
上方抛物线上一动点,过点
作
交
的延长线于点
试探究是否存在点
,使得
的某一个角等于
的
倍?若存在,求点
的横坐标;若不存在,请说明理由.
(4)如图2,当
时,
为直线
上方抛物线上一动点,过点
作
交
的延长线于点
抛物线的对称轴与
轴交于点
连接
试探究是否存在点
使得
与
相似?若存在,求点
的横坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48bc29e5e1713d6627d95470247b185e.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/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4207775cad00ac153927a8164f45c076.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2ff7caec4fdd8fb54a3ffbff9692414.png)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(2)求系数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
请你根据自身能力从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62295c36d2e2174908c2bec0eb5b30f.png)
(3)如图2,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e9222ffc26c0e6bfbf252ab5d8a520.png)
![](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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ea542c31170157c0e9b9e8b65a95437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e4ca8b58be33aa0b01f29308367f84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb49df05f2e31d005735c3f14a21d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d17e587b7fcc3f7ef52c0a542141daa2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
(4)如图2,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e9222ffc26c0e6bfbf252ab5d8a520.png)
![](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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ea542c31170157c0e9b9e8b65a95437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e4ca8b58be33aa0b01f29308367f84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e3ad66cf49d46fe39be15f5c23eec68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a1cf657792edb2da8c7c896d7320c8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8fbc229c957487495bb8cda1d4cfd8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb49df05f2e31d005735c3f14a21d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4807ca16360c0cca436e59d4be98f626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/16/7dfc025c-c935-4d5f-8379-251bab914861.png?resizew=331)
您最近一年使用:0次
4 . 如图12,在
中,
.
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/3d6165ce44584077b330dd7560baf8a5.png)
(1)利用尺规作线段
的垂直平分线
,垂足为
,交
于点
;(保留作图痕迹,不写作法)
(2)若
的周长为
,先化简
,再求
的值.
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/d2503457e3784773b1e25074dddf07c2.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/b59bb3e58dcb4acbb9cd9e642f60659f.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/3d6165ce44584077b330dd7560baf8a5.png)
(1)利用尺规作线段
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/2b3a33ce899444f5addb1cb09355033d.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/229a7754ccc34798a38b1f07f2015950.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/887b24cf70464b15914f6a2e557c0515.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/da22de1582934ef29928e3b64be6c809.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/1e3355f97edb490494294a40e65bac41.png)
(2)若
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/82d0bcd9627c42ca9c131620ca5bcf49.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/7b8a5b38d0024b8bbe3e60051013a69b.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/f109ea068be9446b9a8acbe8afb7402a.png)
![](https://img.xkw.com/dksih/QBM/2017/8/1/1773762719588352/1773762719948800/STEM/65bcdeb824e74c52b9057e6e24a72d2d.png)
您最近一年使用:0次
5 . 已知抛物线
的对称轴与
轴的交点横坐标是分式方程
的解,若抛物线与
轴的一个交点为
,与
轴的交点![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2640e2f1ef08ea8da29e66e4629f2abb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/17/4543ea8f-9b37-46f4-a2bb-02e98ecc257f.png?resizew=161)
(1)求抛物线
的解析式;
(2)若点
坐标为
,连接
,若点
是线段
上的一个动点,求
的最小值.
(3)连接
过点
作
轴的垂线
在第三象限中的抛物线上取点
过点
作直线
的垂线交直线
于点
,过点
作
轴的平行线交
于点
,已知
.
①求点
的坐标;
②在抛物线上是否存在一点
,使得
成立?若存在,求出
点坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90385c676848de67293e3ed6bc000fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ec2dd83c4e11bd9765c49596f0af8aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba6bbadd3c548cc1ec55a8d386a66e17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2640e2f1ef08ea8da29e66e4629f2abb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/17/4543ea8f-9b37-46f4-a2bb-02e98ecc257f.png?resizew=161)
(1)求抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90385c676848de67293e3ed6bc000fe.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/538fcc655a6020a2dd8602beb249b6c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f272958dd9347aa667ecfff4e838dc48.png)
(3)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/178a2a5f277bab230e7e65ee5b8b53a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94dd3389ea93571b83778bf5ed904d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8fbc229c957487495bb8cda1d4cfd8e.png)
![](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/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6150e67d34d30ce44187be80cad7fe84.png)
①求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
②在抛物线上是否存在一点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7466b60c6a14f1f25c728687addb908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
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6 . (1)计算:
.
(2)如图,在
中,
,
,点D为EC边上一点,且
,
,求
的周长.(结果保留根号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e78fa4e5aea195dd2e90828cc51b1dd.png)
(2)如图,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87fd28b8b2bde9de5630a6106a6f762e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f149e83812e72efd7dd3dfc78d0134ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29e240a6378adf6d23ebf9cc710c9bd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2d6ceed6e5a36193bcb5a557853dbee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd9cba0ec6619ed299ee9ab9cdfe482b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://img.xkw.com/dksih/QBM/2019/9/20/2294882190655488/2294970821959680/STEM/25b2758e2e9447c6b69fa73e72e5c322.png?resizew=158)
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解题方法
7 . 如图1,点E在矩形ABCD的边AD上,AD=6,tan∠ACD=
,连接CE,线段CE绕点C旋转90°,得到线段CF,以线段EF为直径作⊙O.
(1)请说明点C一定在⊙O上的理由;
(2)点M在⊙O上,如图2,MC为⊙O的直径,求证:点M到AD的距离等于线段DE的长;
(3)当△AEM面积取得最大值时,求⊙O半径的长;
(4)当⊙O与矩形ABCD的边相切时,计算扇形OCF的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4b8503f4706b8321e4e79a87eadea84.png)
(1)请说明点C一定在⊙O上的理由;
(2)点M在⊙O上,如图2,MC为⊙O的直径,求证:点M到AD的距离等于线段DE的长;
(3)当△AEM面积取得最大值时,求⊙O半径的长;
(4)当⊙O与矩形ABCD的边相切时,计算扇形OCF的面积.
![](https://img.xkw.com/dksih/QBM/2020/7/1/2496307223224320/2497236226899968/STEM/f49657c9179a41508acb57a45c796f8c.png?resizew=314)
您最近一年使用:0次
2020-07-02更新
|
285次组卷
|
3卷引用:2020年河北省唐山市中考数学一模试题
2018九年级·全国·专题练习
8 . (2017内蒙古赤峰市,第24题,12分)如图1,在△ABC中,设∠A、∠B、∠C的对边分别为a,b,c,过点A作AD⊥BC,垂足为D,会有sin∠C=
,则
S△ABC=
BC×AD=
×BC×ACsin∠C=
absin∠C,即S△ABC=
absin∠C
同理S△ABC=
bcsin∠A
S△ABC=
acsin∠B
通过推理还可以得到另一个表达三角形边角关系的定理﹣余弦定理:
如图2,在△ABC中,若∠A、∠B、∠C的对边分别为a,b,c,则
a2=b2+c2﹣2bccos∠A
b2=a2+c2﹣2accos∠B
c2=a2+b2﹣2abcos∠C
用上面的三角形面积公式和余弦定理解决问题:
(1)如图3,在△DEF中,∠F=60°,∠D、∠E的对边分别是3和8.求S△DEF和DE2.
解:S△DEF=
EF×DFsin∠F= ;
DE2=EF2+DF2﹣2EF×DFcos∠F= .
(2)如图4,在△ABC中,已知AC>BC,∠C=60°,△ABC'、△BCA'、△ACB'分别是以AB、BC、AC为边长的等边三角形,设△ABC、△ABC'、△BCA'、△ACB'的面积分别为S1、S2、S3、S4,求证:S1+S2=S3+S4.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d8c176e0c2b435675a3b8efab0e498d.png)
S△ABC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
同理S△ABC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
S△ABC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
通过推理还可以得到另一个表达三角形边角关系的定理﹣余弦定理:
如图2,在△ABC中,若∠A、∠B、∠C的对边分别为a,b,c,则
a2=b2+c2﹣2bccos∠A
b2=a2+c2﹣2accos∠B
c2=a2+b2﹣2abcos∠C
用上面的三角形面积公式和余弦定理解决问题:
(1)如图3,在△DEF中,∠F=60°,∠D、∠E的对边分别是3和8.求S△DEF和DE2.
解:S△DEF=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
DE2=EF2+DF2﹣2EF×DFcos∠F= .
(2)如图4,在△ABC中,已知AC>BC,∠C=60°,△ABC'、△BCA'、△ACB'分别是以AB、BC、AC为边长的等边三角形,设△ABC、△ABC'、△BCA'、△ACB'的面积分别为S1、S2、S3、S4,求证:S1+S2=S3+S4.
![](https://img.xkw.com/dksih/QBM/2018/2/7/1877062186000384/1890390499639296/STEM/d53b5303-0f60-4113-b982-942ff7072a92.png)
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9 . 如图,
、
为反比例函数
图像上的两点,
、
两点坐标分别为
、
,
,连接
并延长交
轴于点
.
(1)求
的值.
(2)若
为
的中点,求
的值.
(3)过
点作
的平行线交
轴于
,若
为整数,求
值.
![](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/03517310ea1e913f709753592ac65ffd.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/e2fc8d014d0fb937a4ae0474a084ddf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f3a41ab0c39653258d099729bac9a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0a968f314fc1bac27fca41559070b4a.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/c5db41a1f31d6baee7c69990811edb9f.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fd1f0ace9ca0b79929e73af6c201c2e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(3)过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55cc0d84872c2958a7b702ac7b5b1d4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/8/7c34656c-aa85-41e5-b430-2cb9715e4ca3.png?resizew=196)
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