解题方法
1 . 欧拉是伟大的数学家,也是最多产的数学家,他在数论、复变函数、变分法、拓扑学、微分方程、力学等等领域都有杰出贡献.1765年,欧拉在他的著作《三角形的几何学》中指出,任意三角形的外心、垂心和重心位于同一直线上(这条直线被称为三角形的欧拉线),此外,外心到重心的距离等于垂心到重心距离的一半.为证明以上结论,我们作以下探究:
如图,点O、G、H分别为△
的外心、重心、垂心.
(1)求证:
;
(2)求证:
;
(3)求证:
.
注:①重心:三边中线的交点,重心将中线长度分成2:1;
②垂心:三条高线的交点,高线与对应边垂直;
③外心:三条中垂线的交点(外接圆的圆心),外心到三角形各顶点的距离相等.
如图,点O、G、H分别为△
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/7/14/4ab99988-00c9-488c-9efa-b3cd7a942bd5.png?resizew=151)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147ab2d582e60bee6d81b27236e7288b.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f1de6cc23279f2a20ab5c8071ab298a.png)
(3)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0b0c2fbcda6ca69ef7d55c2f3b5a310.png)
注:①重心:三边中线的交点,重心将中线长度分成2:1;
②垂心:三条高线的交点,高线与对应边垂直;
③外心:三条中垂线的交点(外接圆的圆心),外心到三角形各顶点的距离相等.
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解题方法
2 . 设
,
.如果存在
使得
,那么就说
可被
整除(或
整除
),记做
且称
是
的倍数,
是
的约数(也可称为除数、因数).
不能被
整除就记做
.由整除的定义,不难得出整除的下面几条性质:①若
,
,则
;②
,
互质,若
,
,则
;③若
,则
,其中
.
(1)若数列
满足,
,其前
项和为
,证明:
;
(2)若
为奇数,求证:
能被
整除;
(3)对于整数
与
,
,求证:
可整除
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b72ea8ec0d9f8b1cfc4de834b8bfb608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87803b7cee18366b89d51799250df510.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6705dba65746e1d4cac6a268b3c806ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.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/020e12ff4f028aba3a205a95e650d72b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.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/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79bda3d07c2fef4d6af4a13ade4c743e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/020e12ff4f028aba3a205a95e650d72b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e4d6df2a57b7e5be32c05c10257ea6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91638bacbf4d15736d26713ba90e0fc4.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/91638bacbf4d15736d26713ba90e0fc4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e4d6df2a57b7e5be32c05c10257ea6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0601879ae4ca9592246d135bfa48658c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/383eb235f8e0ceda13367b16d29e0180.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/503618b9bfb53a06f0ec6a5e427dcdbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0da20edf2714109dcfded7e212ec44a.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e12059d1dac926a235ccd40c3b61b1b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed9dbd8ed61db4f1c14f6b0e5f071200.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e1e4de97f8490fddcff16afe8583266.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20d6fc9b90f370fbb27552876b650f8f.png)
(3)对于整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b96cdd9e003120b6102d927dbf53e39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5009ce2d56180d31204f77c871fb375c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4b326965628b5d967aafe9e696fdc07.png)
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745次组卷
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2卷引用:山东中学联盟2024届高考考前热身押题数学试题
3 . 《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)
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4 . 下图是小明复习全等三角形时遇到的一个问题并引发的思考,请帮助小明完成以下学习任务.
如图,OC平分
,点P在OC上,M、N分别是
、OB上的点,
,求证:
.
小明的思考:要证明
,只需证明
即可.
证法:如图①:∵OC平分
,∴
,
又∵
,
,∴
,
∴
;
请仔细阅读并完成以下任务:
的依据是______(填序号).
①SSS ②SAS ③AAS ④ASA ⑤HL
(2)如图②,在四边形ABCD中,
,
的平分线和
的平分线交于CD边上点P,求证:
.
(3)在(2)的条件下,如图③,若
,
,当△PBC有一个内角是45°时,
的面积是______.
如图,OC平分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2032fccdf9ab12429aae024d67b19d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4acd79bb9fb06f7c806eb6e17e4b613.png)
小明的思考:要证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4acd79bb9fb06f7c806eb6e17e4b613.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94d54326f92838c51a197cc82985e506.png)
证法:如图①:∵OC平分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c1f18cef1745d84a0265246684753bd.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25ce5cddb3791c46d6ef0c32d35a7886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2032fccdf9ab12429aae024d67b19d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/905a8192e8d6365309562606283e9959.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4acd79bb9fb06f7c806eb6e17e4b613.png)
请仔细阅读并完成以下任务:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/905a8192e8d6365309562606283e9959.png)
①SSS ②SAS ③AAS ④ASA ⑤HL
(2)如图②,在四边形ABCD中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/609ada36dd56b33279103ebc1f90bbac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4189a0821a0ffab9dc171ecd279ba442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ed66431681da1db8f7cb0f40cd19201.png)
(3)在(2)的条件下,如图③,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afcd54ff42ebdc70cb273cd5909d549f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
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解题方法
5 . 悬索桥(如图)的外观大漂亮,悬索的形状是平面几何中的悬链线.
年莱布尼兹和伯努利推导出某链线的方程为
,其中
为参数.当
时,该方程就是双曲余弦函数
,类似的我们有双曲正弦函数
.
![](https://img.xkw.com/dksih/QBM/2022/1/23/2900721970536448/2907279254913024/STEM/8a914e2499134cf68207c8add767fe65.png?resizew=325)
(1)从下列三个结论中选择一个进行证明,并求函数
的最小值;
①
;
②
;
③
.
(2)求证:
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/046db679c09a10434e81f7a01c55e243.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ad2f5a11d7437f506adab0996961269.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4580cc037c0c760c728cdbb74a8154c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0099b9b80ed478824fa95677ebe9d5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3321510a9eb73909a36c084a8630e89.png)
![](https://img.xkw.com/dksih/QBM/2022/1/23/2900721970536448/2907279254913024/STEM/8a914e2499134cf68207c8add767fe65.png?resizew=325)
(1)从下列三个结论中选择一个进行证明,并求函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3634cf0ca04b381dec8fcfee8805bdac.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ff61bdd9ed784248cfdcc965ce06db0.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e40ff30f6f7fca28159dedeff7168c74.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95c3de984177769fa426e10eb14cd82c.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0645c3c42e19271f86a10b1fe9dbb0f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b39ee39c38f49390a03be161109a2b4.png)
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2022-02-01更新
|
1403次组卷
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7卷引用:江苏省苏州市2021-2022学年高一上学期期末数学试题
江苏省苏州市2021-2022学年高一上学期期末数学试题湖南省株洲市第二中学2021-2022学年高一下学期“同济大学”杯数理化联赛数学试题重庆市2023届高三下学期3月月度质量检测数学试题湖南省株洲市南方中学2022-2023学年高一下学期期末数学试题(已下线)重难点突破02 函数的综合应用(九大题型)(已下线)压轴题函数与导数新定义题(九省联考第19题模式)讲(已下线)压轴题三角函数新定义题(九省联考第19题模式)讲
名校
解题方法
6 . 微分中值定理是微积分学中的重要定理,它是研究区间上函数值变化规律的有效工具,其中拉格朗日中值定理是核心,它的内容如下:
如果函数
在闭区间
上连续,在开区间
可导,导数为
,那么在开区间
内至少存在一点
,使得
,其中
叫做
在
上的“拉格朗日中值点”.已知函数
.
(1)若
,求函数
在
上的“拉格朗日中值点”
;
(2)若
,求证:函数
在区间
图象上任意两点
,
连线的斜率不大于
;
(3)若
,且
,求证:
.
如果函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f030c36bb8786df88d401792062a4100.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30277e0be448b4955903e81e8795e45d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4b04824a308519a61318a82aa97a05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30277e0be448b4955903e81e8795e45d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f3fcc5073759c73c7a63c8818eca5c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f030c36bb8786df88d401792062a4100.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d11582cafaca7560189cf57e70f6a46d.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58423a31ef72d8d161b775090c9ed2c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bcc88c47bbbace2c56adced4f781b6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d0d09c61ed9d7289d948d2ab559657f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870ebc2f7aabb028024894568d749934.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/25a9a2cda21bc7d84330702878e61c63.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1dffe15ea2b4735ad2a274144301328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1310a7a80d1f8751a3f8cafe7f8c8b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098345d96f648ba45ad923a79e815496.png)
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2024-05-28更新
|
537次组卷
|
4卷引用:2024届山西省高考三模数学试题
2024届山西省高考三模数学试题江西省上饶市横峰中学2023-2024学年高二下学期期末考试数学试卷湖南省常德市第一中学2023-2024学年高二下学期期末考试数学试卷(已下线)专题2 函数与导数新定义压轴大题(三)【讲】
解题方法
7 . 自然常数
是自然对数的底数,是极为重要的常数,通常称为欧拉数.它的发现和研究跨越了多个世纪,涉及了众多数学家的贡献,从雅各布·伯努利的早期工作到莱昂哈德·欧拉的深入研究,再到现代数学家对其性质的进一步探索,充分展现了数学知识的积累和发展,以及数学精神的传承.瑞士数学家雅各布·伯努利于1683年通过研究复利首先发现,即
是数列
的极限.
(1)证明:
;
(2)已知函数
.
①若
,证明:
;
②讨论
的极值点的个数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c32719ba12045c6a71c3115bf61232e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/041a7c8fc017f596542c5e6ec7d1c40b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/674cddb376184fb0b8df6f48d10fb7ee.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db89efaffc2d2196ff132575ca3cde18.png)
(2)已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68e49c389ea12df1529403b8f03a5e4f.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0ffecb03c47be920254c4ccffa5b222.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e9c599e8d420006448905acec2b8234.png)
②讨论
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
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名校
解题方法
8 . 拟合(Fittiong)和插值(Imorterpolation)都是利用已知的离散数据点来构造一个能够反映数据变化规律的近似函数,并以此预测或估计未知数据的方法.拟合方法在整体上寻求最好地逼近数据,适用于给定数据可能包含误差的情况,比如线性回归就是一种拟合方法;而插值方法要求近似函数经过所有的已知数据点.适用于需要高精度模型的场景,实际应用中常用多项式函数来逼近原函数,我们称之为移项式插值.例如,为了得到
的近似值,我们对函数
进行多项式插值.设一次函数
满足
,可得
在
上的一次插值多项式
,由此可计算出
的“近似值”
,显然这个“近似值”与真实值的误差较大.为了减小插值估计的误差,除了要求插值函数与原函数在给定节点处的函数值相等,还可要求在部分节点处的导数值也相等,甚至要求高阶导数也相等.满足这种要求的插值多项式称为埃尔米特(Hermite)插值多项式.已知函数
在
上的二次埃尔米特插值多项式
满足![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c42a7a6dd751bed8ef6e250c4416f35.png)
(1)求
,并证明当
时,
;
(2)若当
时,
,求实数
的取值范围;
(3)利用
计算
的近似值,并证明其误差不超过
.
(参考数据:
;结果精确到0.001)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c849c99d2679990ea508828dd84b72b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/032b5389c9adbac2c99da500243b60b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d702c3e3bfd467cdffa1cde2665a843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/666dc99e433b777214f5dc1159dd8b77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e11f4ca0e7ace69f92130d0525bcdb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26f64fcef2c73573dec5c4050f4a8d9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c849c99d2679990ea508828dd84b72b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04680b4d1f3c78edd7d94821f116b4ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/032b5389c9adbac2c99da500243b60b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e11f4ca0e7ace69f92130d0525bcdb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45a41b2c3837400bf362b6e4bc9c05f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c42a7a6dd751bed8ef6e250c4416f35.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcafc95a0527841c29a58d4f7d85e232.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f7dbb416ec1ff1984a724a4f48bf692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5240d509c68d24c7905228de2c437aa0.png)
(2)若当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f7dbb416ec1ff1984a724a4f48bf692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f67186d47ea156c23dfb970ed9d751f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(3)利用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcafc95a0527841c29a58d4f7d85e232.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c849c99d2679990ea508828dd84b72b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b442f2d96e10ec3e70d70f87e3af6db.png)
(参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb22598288e913690a8f90a8fa7c3612.png)
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解题方法
9 . 我国南宋著名数学家秦九韶在他的著作《数书九章》卷五“田域类”有一个题目:“问沙田一段,有三斜,其小斜一十三里,中斜一十四里,大斜一十五里,里法三百步.欲知为田几何?”其求法是:“以小斜幂并大斜幂减中斜幂,余半之,自乘于上.以小斜幂乘大斜幂减上,余四约之,为实;一为从隅,开平方得积.”这就是秦九韶推出的“三斜求积”公式.若
的内角
的对应边分别为
,面积为
,则“三斜求积”公式为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab1c6a7fab355a3f6ec98a10727363dd.png)
(1)用“三斜求积”公式证明
;
(2)若
,且
,求
面积的最大值;
(3)定义:四面体中,若异面棱长相等的四面体为等腰四面体.设等腰四面体
的外接球表面积为
的外接圆面积为
.已知
,且
,
,试用
表示
,并求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab1c6a7fab355a3f6ec98a10727363dd.png)
(1)用“三斜求积”公式证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95cce11ea3c8b3b4878c6d7b516ed961.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/241c773ea15220a35e381643cf757831.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(3)定义:四面体中,若异面棱长相等的四面体为等腰四面体.设等腰四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8a65b64c35ab151bc4deb2ca5a99a79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13496be07af01f06313f648225d71c74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/532f94a827223d60eca31df9547fef3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ac9fe346a9a6d9f9af61e2077fcc7a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6af2b186356358d1cc3e8cdadc8a0502.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a14c388e1e2e5a2ff1ccf6caffbee0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ad5a9147b25285124851a61c7d1a24a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ad5a9147b25285124851a61c7d1a24a.png)
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解题方法
10 . 下图中的一系列三角形图案称为谢尔宾斯基三角形.图(1)是一个面积为1的实心正三角形,分别连接这个正三角形三边的中点,将原三角形分成4个小正三角形,并去掉中间的小正三角形得到图(2),再对图(2)中的每个实心小正三角形重复以上操作得到图(3),再对图(3)中的每个实心小正三角形重复以上操作得到图(4),…,依此类推得到
个图形.记第
个图形中实心三角形的个数为
,第n个图形中实心区域的面积为
.
和
的通项公式;
(2)设
,证明
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1256609d7bb6cfdb898b29b383cedeb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd64bdb163bfe6acbc04400eb6da8d63.png)
您最近一年使用:0次