如图,在
中,
,把
绕点A顺时针旋转,使
落到
延长线上的
处,得到
,点B的对应点为D,点C的对应点为E,旋转过程中得到两条弧
,
,
与
交于点F,连接
.
(1)求
的度数;
(2)若
,求阴影部分的面积;
(3)若
,弧BD与线段
只有一个公共点D,直接写出线段
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c646c683fbe522edb7ea54fd3ad873d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8192018a58bb1fe23769a48a4d9042ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bf05f26cb828910e47ddb5c8dedd66.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/20/96b53da9-d6ec-4597-a4ec-1ef400004189.png?resizew=162)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/384da7acfefa7c656eaca2df173f0cb6.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/454328a8e75953fdb0835ce80d9566e3.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
2023·河北石家庄·三模 查看更多[5]
2023年河北省石家庄市九地市6月份中考三模数学试题(已下线)2023年河北省中考数学真题变式题21-26题河北省邯郸市峰峰矿区2023-2024学年九年级上学期期中数学试题河北省沧州市东光县2023-2024学年九年级上学期期中数学试题(已下线)2023四川省乐山市中考数学变式题22-26题
更新时间:2023-06-16 15:36:19
|
相似题推荐
解答题-问答题
|
较难
(0.4)
【推荐1】如图1,在正方形
中,
,点 O,E在边
上,且
,
,以点O为圆心,
为半径在其左侧作半圆O,出分别交
于点 G,交
的延长线于点F.
______;
(2)将半圆O绕点E逆时针旋转
,点O 的对应点为
,点 F 的对应点为
.
①如图2,若M为半圆
上一点,当点
落在
边上时,求点M到线段
的最短距离;
②如图3,当半圆
交
于P,R两点时,若
,求此时半圆
与正方形
重叠部分的面积;
③当半圆
与正方形
的边相切时,设切点为N,直接写出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78b65065ec3a0cb4b050989165c003d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0761165f1176f3a5fe4f7b052832316d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de28a15a50479d7f0c61ede81070922f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/694e8e1384425dc3f7f80fedda9f7b8f.png)
(2)将半圆O绕点E逆时针旋转
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/151aa00898cc4398afeb89c197456aae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8e55590555905eb4f57889bbd16e39a.png)
①如图2,若M为半圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8e55590555905eb4f57889bbd16e39a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
②如图3,当半圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b49bf874b8a4f06cd71e1b1037eac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
③当半圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b43d3683e7f5aabe2eb2ae3da7188d96.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
【推荐2】如图,形如三角板的
中,
厘米,形如量角器的半圆
的直径
在直线
上,且
厘米,点
在三角形的左侧,
厘米.若半圆
沿
方向以每秒2厘米的速度向右运动,设运动时间为t秒.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/7/0b6a1974-c8e9-471d-b40f-2bc33767b379.png?resizew=246)
(1)当
______时,半圆
与直线
相切;
(2)当
时,试判断直线
与半圆的位置关系并说明理由;
(3)当
时,求半圆与三角形重合部分的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd805a87740eab1f14e0e4733381a336.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ee4f58ec0a81d46ff0557b9220ba606.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4ab0cbcf1eaecea7423b50fcf955a6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/7/0b6a1974-c8e9-471d-b40f-2bc33767b379.png?resizew=246)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/825116eb345f5505ebc8c1cdb8a1f131.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a495c197fcbacb8c109aa0060525a371.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d535a4d2666de49bb57c25c8808f0feb.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐1】如图,已知
的半径为4,
是
的直径,
为
的弦,B为
延长线上的一点,
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/13/d36e31b1-04d1-43fe-bb20-b33fe736a61b.png?resizew=191)
(1)求证:
为
的切线;
(2)求弦
的长;
(3)求图中阴影部分的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb01d2b57580731c8b807ac8cffc8ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/13/d36e31b1-04d1-43fe-bb20-b33fe736a61b.png?resizew=191)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)求弦
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(3)求图中阴影部分的面积.
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】如图,四边形
内接于
延长
交于点
.点
在
上,且
.
![](https://img.xkw.com/dksih/QBM/2020/6/26/2493106677374976/2493961686695936/STEM/44018f49f13b4e8cb9cbd2f5eaaee359.png?resizew=275)
(1)求证:
是
的切线;
(2)已知
,求
的长;
(3)在(2)的条件下,求图中阴影部分的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03f843752c334821a4afdfe987a345f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ba48366317ebea1c9dd5e4e67e03092.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/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fe6d389a6c448d92b79d89bc9e8489f.png)
![](https://img.xkw.com/dksih/QBM/2020/6/26/2493106677374976/2493961686695936/STEM/44018f49f13b4e8cb9cbd2f5eaaee359.png?resizew=275)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f6640b80feea180991ff506b5afe41e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(3)在(2)的条件下,求图中阴影部分的面积.
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
【推荐1】如图①,在
中,
,
,
,点O为
内一点,连接
,
,
,且
,以点B为旋转中心,将
绕点B顺时针方向旋转
,得到
(点A,O的对应点分别为点
,
),求:
__________
;
(2)求
的值;
(3)延伸迁移:如图②,
中,
,
,
,点P是三角形内一动点,请直接写出
的最小值.
![](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/ca036d049f5205cf04cb1b9c5cd03f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb01d2b57580731c8b807ac8cffc8ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1438142deeac876fc7dc50552e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdc93e193fad261689949a52819753f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2765ee49bfe09fed44327e8be2347dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866b81a8384cce4f24867baca2e6820c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85895df2a4416494ae679f8f9027425b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12fe32dfbd66709875c5b9f79c9496da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29ffd441a29ea3ad6b86490c8cba2253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83873a9d782f2588c5eedbfe73f9bc2f.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c62635ee088808196e070c44ba6c20fb.png)
(3)延伸迁移:如图②,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26fdd8e57562ba94e10e7f1d770826d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7ed53a398b1d6b7b4abbb43a9abcf1f.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】通过类比联想,引申拓展研究典型题目,可达到解一题知一类的目的,下面是一个案例,请补充完整.
原题:如图1,点
、
分别在正方形
的边
、
上,
,连接
,试猜想
、
、
之间的数量关系.
(1)思路梳理
把
绕点
逆时针旋转
至
,可使
与
重合,由
,得
,即点
、
、
共线,易证
≌ ,故
、
、
之间的数量关系为_________;
(2)类比引申
如图2,点
、
分别在正方形
的边
、
的延长线上,
,连接
,试猜想
、
、
之间的数量关系为,并给出证明.
(3)联想拓展
如图3,在
中,
,
,点
、
均在边
上,且
,若
,
,求DE的长.
原题:如图1,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192155e6a3aade305b76b1eb7c75e30c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/12/be09c678-aa9f-41ec-8931-448be0118f08.jpg?resizew=449)
(1)思路梳理
把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bbd6f0a0412d0f43ce1f7c1d530e56e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5406da6da56fab36d73d59cdb6237fc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09b786297e18a79a55cfb976a1435ec7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7572ecc467c061ef71cf4486ec63ec3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
(2)类比引申
如图2,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192155e6a3aade305b76b1eb7c75e30c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
(3)联想拓展
如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/bfe53ec018b3cb313b48e4267f27017e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/714cc3707bba3bfdb56e251999be8592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/599bfec40f2ce09a75535ac6052701a9.png)
您最近一年使用:0次
解答题-计算题
|
较难
(0.4)
真题
名校
【推荐1】综合与实践
车轮设计成圆形的数学道理
小青发现路上行驶的各种车辆,车轮都是圆形的.为什么车轮要做成圆形的呢?这里面有什么数学道理吗?带着这样的疑问,小青做了如下的探究活动:
将车轮设计成不同的正多边形,在水平地面上模拟行驶.
,
,圆心角
.此时中心轨迹最高点是C(即
的中点),转动一次前后中心的连线是
(水平线),请在图2中计算C到
的距离
.
(2)探究二:将车轮设计成正方形,转动过程如图3,设其中心到顶点的距离是2,以车轮转动一次(以一个顶点为支点旋转)为例,中心的轨迹是
,
,圆心角
.此时中心轨迹最高点是C(即
的中点),转动一次前后中心的连线是
(水平线),请在图4中计算C到
的距离
(结果保留根号).
(3)探究三:将车轮设计成正六边形,转动过程如图5,设其中心到顶点的距离是2,以车轮转动一次(以一个顶点为支点旋转)为例,中心的轨迹是
,圆心角
______.此时中心轨迹最高点是C(即
的中点),转动一次前后中心的连线是
(水平线),在图6中计算C到
的距离
______(结果保留根号).
(4)归纳推理:比较
,
,
大小:______,按此规律推理,车轮设计成的正多边形边数越多,其中心轨迹最高点与转动一次前后中心连线(水平线)的距离______(填“越大”或“越小”).
(5)得出结论:将车轮设计成圆形,转动过程如图7,其中心(即圆心)的轨迹与水平地面平行,此时中心轨迹最高点与转动前后中心连线(水平线)的距离
______.这样车辆行驶平稳、没有颠簸感.所以,将车轮设计成圆形.
车轮设计成圆形的数学道理
小青发现路上行驶的各种车辆,车轮都是圆形的.为什么车轮要做成圆形的呢?这里面有什么数学道理吗?带着这样的疑问,小青做了如下的探究活动:
将车轮设计成不同的正多边形,在水平地面上模拟行驶.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05cb00c4466d7b1d82fef55e2addbcb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eee296a7d9fba487f1485c61580196f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5edf900c810371fb21297c15f86d8743.png)
(2)探究二:将车轮设计成正方形,转动过程如图3,设其中心到顶点的距离是2,以车轮转动一次(以一个顶点为支点旋转)为例,中心的轨迹是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05cb00c4466d7b1d82fef55e2addbcb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b31ac1def558351e2e3ed1235c570530.png)
(3)探究三:将车轮设计成正六边形,转动过程如图5,设其中心到顶点的距离是2,以车轮转动一次(以一个顶点为支点旋转)为例,中心的轨迹是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c0c46783b77cce2bd4b45b9acc61884.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bd6ffb78dad3375efa3b08ab518553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87d3acd0add588e7d5cf605b2764f514.png)
(4)归纳推理:比较
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5edf900c810371fb21297c15f86d8743.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b31ac1def558351e2e3ed1235c570530.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d0252c1b2f7d2a84b5c985d19d547.png)
(5)得出结论:将车轮设计成圆形,转动过程如图7,其中心(即圆心)的轨迹与水平地面平行,此时中心轨迹最高点与转动前后中心连线(水平线)的距离
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
解题方法
【推荐2】如图1,顶点为
的抛物线
交
轴于
,
两点,其坐标分别为
,
,交
轴的正半轴于点
,
是线段
上异于
,
的一个动点,
为
上一点.
(1)求该抛物线的表达式并写出点
的坐标.
(2)当
时,求
面积的最大值.
(3)如图2,
的延长线交
于点
,若
,记
,
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f18269e4b2c08f69b719c4c7e7d71733.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.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/bd243fab0af865af67a2ab817e909cf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edb13bbc5335efc427f9c619a51dae3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.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/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/15/d5eb573f-e0f7-4bf9-88fb-03b213769eeb.png?resizew=340)
(1)求该抛物线的表达式并写出点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/402ab8c49c4dd2aaa0ef47164c7cac00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
(3)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e694643c17615cbd5dd7da7cee5e3377.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/572cc97dd3f29bc6bc14cd0ed4738af2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb30143f9277500f574efa816cd47c28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4c21cbb1c2bcbcb8391ac5a879f2ae0.png)
您最近一年使用:0次