解题方法
1 . 法国著名军事家拿破仑
波拿巴最早提出的一个几何定理:“以任意三角形的三条边为边向外构造三个等边三角形,则这三个三角形的外接圆圆心恰为另一个等边三角形的顶点”.如图,在
中,内角
,
,
的对边分别为
,
,
,已知
.以
,
,
为边向外作三个等边三角形,其外接圆圆心依次为
,
,
.
;
(2)若
的面积为
,求
的面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c97ec04a1aa7ac6fce72d589864940a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/c5db41a1f31d6baee7c69990811edb9f.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/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f83f04929a0b205b78e2d87b7079ecd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4f6f74444b2b7947fc6e35c8d62322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dacb04fa29178c0af4353e4369a7e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7736a0467e1127dc3963098e148ca64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18483c9c195ecd922772527fa85c0fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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解题方法
2 . 赵爽是我国古代数学家,大约在公元222年,他为《周髀算经》一书作序时,介绍了“勾股圆方图”,亦称“赵爽弦图”.(以弦为边长得到的正方形由4个全等的直角三角形再加上中间的一个小正方形组成,如图①),类比“赵爽弦图”,可构造如图②所示的图形,它是由3个全等的三角形与中间一个小等边三角形拼成的一个较大的等边三角形,其中
,则
的值为______ ;设
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96724b211bf3e56d588bd430aa3f2894.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01bbe0491dc037390ef465b4deef4a20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1412e959d8e97ae6bee534a319662e84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9e507d3941363e9dbeac8be35134727.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96724b211bf3e56d588bd430aa3f2894.png)
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解题方法
3 . 直四棱柱
的所有棱长都为
,
,点
在四边形
及其内部运动,且满足
,则点
到平面
的距离的最小值为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bbaccd578a43b2397c8bdd50592fa07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bf9ef324f1289e205e29fed105c38e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f88e265ee000aed605e9fdf328745930.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15b78c047642924fe864028c81b1f49d.png)
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解题方法
4 . 在
中,
,满足此条件的
有两解,则
的取值范围为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f84bbedc96769d2c22df04745121165a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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5 . 已知
,向量
,且满足![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb6a037ca43e342496f5b00870a8689.png)
(1)求点
的坐标;
(2)若点
在直线
(
为坐标原点)上运动,当
取最小值时,求点
的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baba5942e11975cd2383393d7e619136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7199e5758b135764a980570891013940.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb6a037ca43e342496f5b00870a8689.png)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7787dfab61ed9830b531da365e592bbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
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解题方法
6 . 在直角三角形
中,
,点
在边
上,且
,设
.
(1)若
,求
的值;
(2)若
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8652515789d01ab3af8c9986cf94274a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/379556ae8865fdf6430f71be2a99f71e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf718980f931b3f21a332916404fef2f.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/759b29a7b2b3735306f1a650355a7858.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ee25a78681febe00db64902902420ea.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da336bc7d2112ecff7d1e632ea2df748.png)
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解题方法
7 . 阅读下面材料:在空间直角坐标系
中,过点
且一个法向量为
的平面
的方程为
,过点
且方向向量为
的直线
的方程为
.根据上述材料,解决下面问题:已知平面
的方程为
,直线
是两个平面
与
的交线,则直线
与平面
所成角的正弦值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a834024400d0730af3e640ca4d5f54b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baf95be25d34a7366bf4060d081329c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1570746ca504965aa6f176e46a0c2760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b523a8c1993478f6599680dc3b3dc45b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baf95be25d34a7366bf4060d081329c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392440bbbea2ec683d8f1786370407ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/452af21e95f71dc626c04fafafd8ca49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/975d88a135a66a0ee0fb6b13f6b87b9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e23fc11a3a7592c68b20f93bdde2ed3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c001d43d68ea1cd6461c73ee48b1b4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
8 . 在
中,点
是线段
上一点,点
是线段
上一点,且
,
,则
( )
![](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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e44dda388cb29c74ababb811aab2fbc4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dd85a0f2ff80c84bf23eb808a349320.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5085e3cdef9ea6c564e079f745d6fdb.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . 设
为实数,若向量
.
(1)若
与
垂直,求
的值;
(2)当
为何值时,
三点共线.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0192561f4ead4f95871b50f2c2a8d5b7.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93c0f0a6242f7b1313fd149d797ef62e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef8337706c550bc095d7a2bd872221a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
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解题方法
10 . 已知
,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b06f37bd322af6e273ceb66bac49a716.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/969b106918cf44777d177a0538da8cb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7454629359a7e14a85da0428c1b03f36.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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