1 . 如图,在
中,
,G为重心,P为射线
上一点,满足
,Q为射线
上一点,满足
,证明:
、
的外接圆的另一个交点在
上.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8f88798ec42a58dccd212586382b23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4231fb7417dec02f64506e6e35639e36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e322e0c87479bba874db9ae9ba36b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ea46dcc277f459e6af6d5b9376cd9c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5b084bab4536bb3fd7d630252016c83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/004dd87e3afff786d4a10ac524706487.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/4af6bf23-95fd-449c-8652-08602ff2ab75.png?resizew=241)
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2 . 设函数
满足对于每个
,均存在一个
,使得
,其中,
是f复合m次.设
是满足上述条件的k中的最小值,证明:数列
无界.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3df6c82d43d84c952ea65b9508306cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deffbcb0165f1a90a435d50118a14b68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/641314f7a1c387a45aac2ca9ee815150.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62eb22a7e6a88d836a0b6c97af0b30b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d1c48d12cf6f92ed5bbd15ac2668e0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bbbf4d763f3cbe5a71707bc19c78191.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e36f86937e11389c7b7a5012735bd788.png)
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3 . 设
均为正数,证明:
(1)若
,则
;
(2)若
,则
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6aa7413d61d5f084dff82223388b5c5.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bde47288bc17f24c9a05ced2e48cb5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bddaa8662b7e7df9e093b924ea7aaea.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23067dc8ae6048baaf5507cbc5b76172.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6faf3b389d760578d8c1c3934c56c969.png)
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4 . 对每个正整数n,定义
为从1到n中所有与n不互质的正整数的和.求证:若
且
,则
是合数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38fcec7af3520884b173b29bda6c657a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a9ba50ede8ef97b843accf839fef5c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7d9712c3b25f3030e166e136d3a4686.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae9dd56551121a5b88be4dc6910c9ec0.png)
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5 . 如图,在
中,
,且
为
边上的高,
为
边上的中线,
为
的平分线,
与
分别交于
两点,
与
交于
点,令
.求证:
,且
是最好的界(即可以无限接近于
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/844bfe106baea0caf51cd2228b54dbe8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194741f4d2ae7ee44cafca780361446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69995843d21aed8728363afe2fbb6462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc57cface1f8ce1045c96d97de692fc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500acc25d51dc3519a17c2ffa7fccdee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7900d4dcf3cf3aa4e5ae000766083819.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e6486784415f3537c9a13556c05d893.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b624e6d456c5aa077dfd00ada3a311d4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/b68ec419-9dc9-469b-9b36-b6ddfdf7433d.png?resizew=199)
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6 . 如图,锐角
中,
为边
中点,
内切圆与边
切一点
的内切圆与边
切于点
,若四边形
为平行四边形,求证:
在
的平分线上.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cbc944ca5f456dc6ece9fa58a7bbb6f.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/25ae006f399a4b83fb384de288c860b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://img.xkw.com/dksih/QBM/2021/7/20/2768301525590016/2769082901225472/STEM/94a7ced5a2c04ff2879a4f42b5a76699.png?resizew=185)
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7 . 设
,记:
,其中求和是对1,2,…,n的所有
个k元组合
进行的,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0610af5abf3cc278643f5696f58b625d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12b645e448faf42a5eec1a1e02b85325.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c015bd3b114c45ca0881c8468b4b35d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/800cc73c3cf1e852b3cb2eb9dc1ff3f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/663211001b3f08bcbe2cf4a9c9ee0505.png)
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8 . 在锐角
中,D为边
上一定点,P为
边上一动点,直线
交
于点Q,
交
于点X.
、
、
的三个外接圆分别交
于X外的另三点
、
、
,过
、
、
分别作
垂线
、
、
,证明:
、
、
均过定点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a97d0a38b4bcbe8deff0045ca59f151.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef8fe16a80bc081ce853a20420ae33ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1a9da17327dbb03e5cae4a081d46533.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/351bb3f3c54604330fa5b6c2bc3a7502.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177b7f56650f15cdcabd287ee39554d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a9b86a58f9b76942e92c895ed75352.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/351bb3f3c54604330fa5b6c2bc3a7502.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177b7f56650f15cdcabd287ee39554d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a9b86a58f9b76942e92c895ed75352.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fce9427c9b17e4d3cda0c3ff3e2e14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fce9427c9b17e4d3cda0c3ff3e2e14.png)
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9 . 如图,
、
为圆的两切线,
为圆的一条割线,
为切点连线,D为过C、B关于圆的切线的交点,证明:D、E、F共线.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/8330969a-3658-4c62-809a-2ac00336a02a.png?resizew=134)
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10 . 证明:如下构造的空间曲线
的任意五等分点组都不在同一球面上,曲线
的构造:作周长为
的圆
,在圆
上取
使
的长度
,并以
为轴将
旋转
得弧
,在圆
上取
,使
的长度
的长度
,并以
为轴将
旋转
度
得弧
,这样,由弧
组成的曲线便是空间曲线.(如图所示)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b454cdb97c408300b50d945f002c2cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b454cdb97c408300b50d945f002c2cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98f69efb8aaef270592e2a32f9f6fd0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86f080d52915f40ffb67cafe152a2055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f201a6027943943b7676e9df993c7beb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98f69efb8aaef270592e2a32f9f6fd0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfe639eab78eafd2d40ea70aa5d3f21d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9038d9adf9dc5b1681d7d64b61841b42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/698c5e524a28c65596a98d2d4c1792df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98f69efb8aaef270592e2a32f9f6fd0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fe2120b570a8a20ddb2a8f52303d277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f201a6027943943b7676e9df993c7beb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/698c5e524a28c65596a98d2d4c1792df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee4e305b89e39d4297d014129e5f0bd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/018a5b0c0e1883258c6b9b1c359d02a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03cb43d6dce3af40aceb3525fb4c073a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/5cdf04bd-85fc-4e23-863e-03c4cf7c33c9.png?resizew=176)
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