名校
解题方法
1 . 已知一个平面内的三个向量
,
,
,其中![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9feedc68e0c2d1b0de51d28e61496e59.png)
(1)若向量
为单位向量,且与
共线,求向量
的坐标;
(2)若
,且
与
垂直,求向量
与
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23bd18136e4e71e1e267bc9f8634b932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec82bd4e0fb7887e5999b8220f60b073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ecf646bc2e4cdd46fc5cc40d741dab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9feedc68e0c2d1b0de51d28e61496e59.png)
(1)若向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ecf646bc2e4cdd46fc5cc40d741dab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23bd18136e4e71e1e267bc9f8634b932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ecf646bc2e4cdd46fc5cc40d741dab5.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5404940e86fc3db18adcb5be78e2e276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59feec0a253476e1baa7ac2d196da24c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abb1d6b61205267d523c5cab8ac68cf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23bd18136e4e71e1e267bc9f8634b932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec82bd4e0fb7887e5999b8220f60b073.png)
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2 . 已知
的展开式中
项的系数为
,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6df371dce7cd2d464270768d344fbf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0a89e3c30f6e4d4c5db4378b05d987.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1480672ec92c4698aac745b029ad8d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
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3 . 我国南宋数学家杨辉1261年所著的《详解九章算法》一书中展示了二项式系数表,数学爱好者对杨辉三角做了广泛的研究,则下列结论错误的是( )
A.![]() |
B.第6行、第7行、第8行的第7个数之和为第9行的第8个数 |
C.第12行中从左到右第2个数与第3个数之比为![]() |
D.第2020行的第1010个数最大 |
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名校
4 . “杨辉三角”揭示了二项式展开式中的组合数在三角形数表中的一种几何排列规律,如图所示,则在第10行中最大数为___________ .
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5 . 在学校组织的一次活动结束后,3名男生和2名女生站成一排照相留念,其中2名女生不相邻,则不同的站法有( )
A.120种 | B.72种 | C.48种 | D.24种 |
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6 . (1)求
的值;
(2)若等式
成立,求正整数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64fbe5c094e34a7cc0a5ba97344d0a34.png)
(2)若等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60a6f3eb1ec177fb8f01437fe7a263e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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7 . 已知事件A,B,C满足A,B是互斥事件,且
,
,
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7db644de80863383f2f46f898178899d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b51f0a6651d55a7e8795b36710b2530.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/995547b367dd77d939697d290d0f85fa.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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8 . 设数列
和
都为等差数列,记它们的前
项和分别为
和
,满足
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dda309e849ab648190ac38b942a150c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98904bedbce77c4bb629a97d46beb476.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
9 . 已知平面向量
,
不共线,
,
,若A,B,C三点共线,则实数
等于( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/384b2ccf546307ca196445a9a58be81c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48834ec58187059ec73b8606f6c8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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10 . 如图,为了测量两山顶
间的距离,飞机沿水平方向在
两点进行测量,
在同一个铅垂平面内.已知飞机在
点时,测得
,在
点时,测得
,
千米,则
( )
(提示:
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d63368fb5c4feebe59c81bd5c90d8eaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54cc97b5f2f221d172c2c98484c0bf02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80be421a052e5eb07a61115d89cdf9ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/351e0ae44264ea8e5f71e50f7cc53cda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a2b3247afa684b10c8e1da99cf33d5b.png)
(提示:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b68f4ac11ec17ec3bee7e128dafaaaa.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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