1 . 窗花是贴在窗户上的剪纸,是中国古老的传统民间艺术之一,图1是一个正八边形窗花隔断,图2是从该窗花图中抽象出的几何图形的示意图.已知正八边形
内角和为
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96724b211bf3e56d588bd430aa3f2894.png)
______ ;若正八边形
的边长为2,P是正八边形八条边上的动点,则
的最大值为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d17d4a6cf11cda87b3dfafaecdec683f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a1e8072b2126e33aa203db4635211a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac2535c0d4662a3a92cabbd44dcdd6d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96724b211bf3e56d588bd430aa3f2894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d17d4a6cf11cda87b3dfafaecdec683f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e83b9f01e806bf74042ba41b26423022.png)
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2 . 降维类比和升维类比主要应用于立体几何的学习,将空间三维问题降为平面二维或者直线一维问题就是降维类比.平面几何中多边形的外接圆,即找到一点,使得它到多边形各个顶点的距离相等.这个点就是外接圆的圆心,距离就是外接圆的半径.若这样的点存在,则这个多边形有外接圆,若这样的点不存在,则这个多边形没有外接圆.事实上我们知道,三角形一定有外接圆,如果只求外接圆的半径,我们可通过正弦定理来求,我们也可以关注九年义教初中《几何》第三册第94页例2.的结论:三角形外接圆的直径等于两边的乘积除以第三边上的高所得的商.借助求三角形外接圆的方法解决问题:若等腰梯形
的上下底边长分别为6和8,高为1,这个等腰梯形的外接圆半径为__________ ;轴截面是旋转体的重要载体,圆台的轴截面中包含了旋转体中的所有元素:高、母线长、底面圆的半径,通过研究其轴截面,可将空间问题转化为平面问题.观察图象,通过类比,我们可以找到一般圆台的外接球问题的研究方法,正棱台可以看作由圆台切割得到.研究问题:如图,正三棱台的高为1,上、下底面边长分别为
和
,其顶点都在同一球面上,则该球的体积为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adbd3e8cf8325999cde03adf845d3dd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41322821ce31416fdac8dd6e0aa41c71.png)
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3 . 我国魏晋时期的数学家刘徽创造了一个称为“牟合方盖”的立体图形,如图1,在一个棱长为2r的立方体内作两个互相垂直的内切圆柱,其相交的部分就是牟合方盖(如图2),我国南北朝时期数学家祖暅基于“势幂既同则积不容异”这一观点和对牟合方盖性质的研究,推导出了球体体积公式.设平行于水平面且与水平面距离为
的平面为
,则平面
截牟合方盖所得截面的形状为______ (填“正方形”或“圆形”),设半径为r的球体体积为
,图2所示牟合方盖体积为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/625dbbd5d5f2617b7c53acdb936b1d07.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82d38e62ba27b42d838c51a6e0a88e40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4764374bd2fb78e59cd0b283637baeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63055a5d6916f99d07fede49120753f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/625dbbd5d5f2617b7c53acdb936b1d07.png)
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4 . 已知函数
图像的相邻两条对称轴之间的距离为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9448bf1d6136b3a108e7ea60506ad39.png)
______ ,
在
上的值域为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3295753865cd125896be1e9e71674a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9448bf1d6136b3a108e7ea60506ad39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a7a27c325208b78078b1058321e1660.png)
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5 . 如图所示,用斜二测画法画出的水平放置的
及
边上中线
的直观图是
及
,其中
,试按此图判定原
中的
四条线段中最长的线段是__________ ;最短的线段是__________ .
![](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/b8ee6e1d480ece7117e1f87ebf4bbeea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/284750727aa2c32b2477d126daefb329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea0cf7f2c14a5210111308feb679fc5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d47b7618fab4fa205b3147a0fa3abc9.png)
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6 . 在
中,角
对应的边分别为
,已知
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5f1e5d29de6e4d72bfed62d9c14dde5.png)
______ ,
的面积为______ .
![](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/8d12de0fe32eedb8fab4fd3a50dfa7a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f2bc8adc993cad5553d66285b5971f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5f1e5d29de6e4d72bfed62d9c14dde5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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7 . 如图①,矩形ABCD中,
,
,E,F分别为AB,DC的中点.将四边形AEFD沿EF折起至四边形
的位置,如图②.
在平面
上的射影为
的中点,则三棱锥
的体积为________ ;
(2)当平面
与平面
垂直时,作正方体
如图③.若平面
平面
,且平面
截该正方体所得图形的面积记为
,则
的最大值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ccd49a0c3ccd22943c15ed7bf0f4c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03952d664fba91020fc5f3bcf2f9746.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/945fbe95bfb4e8e37e619e2d767efef6.png)
(2)当平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ccd49a0c3ccd22943c15ed7bf0f4c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03952d664fba91020fc5f3bcf2f9746.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0bc49d40da6aebbb370be30fa2e6c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/414844edd458857bdfc80bffa61cbf9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecba239ca1f109309bf14fab784ea827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
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8 . 已知点
,
,
,
.
(1)设线段AB的中点是H,若
,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
________ ;
(2)已知
.若点Q的轨迹与直线
平行,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19b62194097ac66a5093c57fca2f5b4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50edfb9ed0d50d6f35ad6a130208d307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e717fc336c2b9c1617421b5b8a4ae6b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/656de1832d5046c5c0d242372ff48c08.png)
(1)设线段AB的中点是H,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/805e8f0e7b46332052b32f249b5df425.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/469ef1bfbac0fa50e8d54110b27ba46f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d77f5191798242b7b9b88a75e17e4425.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
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9 . 在复平面内,复数
对应的点Z的坐标为________ ;![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e0aeeb125cfb42e33094594d4381f5.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56e951f086d8b0f8459878656eb29274.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e0aeeb125cfb42e33094594d4381f5.png)
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10 . 在四边形
中,
,则实数
的值为______ ,若
是线段
上的动点,且
,则
的最小值为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de4fec47150e684e8b270289048aff7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d92b9548115581546be6f0a3c5a7057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2ab157cd50abfa3a6de8027f3f0b424.png)
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