1 . 若一组数据
的方差是5,则数据
的方差是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fe1c31a81f198c443e71b83ca662939.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0539afa6a847e42683ddc877e5264b8d.png)
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2 . 已知一个样本由三个
,三个
和四个
组成,则这个样本的标准差![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c7e7449010436e00dce3b6924a4258.png)
______
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c7e7449010436e00dce3b6924a4258.png)
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3 .
中,角
的对边分别为
,若
,
,
,则
( )
![](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/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5742b2684d00be50a66e01c9acb6b51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99f2f1eb2beb23690f56a68dc7da08cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1f9fabbbe61a759e52ec975215e2e7c.png)
A.![]() | B.![]() |
C.![]() ![]() | D.![]() ![]() |
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4 . 已知某运动员每次投篮命中的概率都为
,现采用随机模拟的方式估计该运动员三次投篮恰有两次命中的概率:先由计算机产生0到9之间取整数值的随机数,指定
表示命中,
表示不命中;再以三个随机数为一组,代表三次投篮结果,经随机模拟产生了如下12组随机数:
,据此估计,该运动员三次投篮恰有两次命中的概率为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d0797a4e8f5cb2a7746ce2e4ea4e81f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f14db37344529d273e36d835241d0d39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6f6a65715c0bea85a53880908cda517.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62264173103abeb0f16df50632a5b923.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1139c55a2ab02b802c77bc0cb941befd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5405ae76ce2ff5df270e8b26f366f690.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bde0b80d15ddfba7a6edfed73e7cfc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0fbd6636656c80c77e28cff098792ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b27812a2c2a50ef94cb2aa0dec29908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1760eb49a53a040d7c78c34b6eaa9331.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afaceabc30c5d1bf842fca92a1c22b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fb6310e94b6eaf243c19df076d115c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c464e44d32fb3d1560bc394d57ee6a4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194e65cdf017d49bfeb076f19a0d2a17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eef4dfe2551509bf0bc073e535d8eaf.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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5 . 已知
的三个内角A,B,C的对边分别为a,b,c,且
.
(1)求证:
为等腰三角形;
(2)若
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0e65f3ca149022d8a0ee5f70e9fa776.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35639227440e8dc58074332230523d9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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6 . 已知复数
(
为虚数单位),则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb0bada9ba3481a183c3463b6ea05907.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7035cd4adda5d72a9fc9f9fda75995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e0aeeb125cfb42e33094594d4381f5.png)
A.1 | B.2 | C.![]() | D.![]() |
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7 . 已知
的边长均为1,点
为边
的中点,点
为边
上的动点,则
的取值范围是( )
![](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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e725e9a770017dcb95095dd78ff39954.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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8 . 已知函数
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0d0a191ad038b6fc08d08311048d228.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb04d514baf56eec084671b88898770b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98cf78bc7435d06dd8a9112c5c8a178b.png)
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9 . 已知
,且
.
(1)求
,
的值;
(2)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1eca7f8e63042b1c98badc0d9e36af1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/353b4f6ed38b5bd83d2f0fa64d686cef.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc8c56d09485b718a85ed23f637e2d77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1a86df8b3934891c1d2e9016f6c4477.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f15d37ff33a395f8d35659abf4a34f0f.png)
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10 . 下列不等式中成立的是( )
A.![]() ![]() |
B.![]() ![]() |
C.![]() ![]() |
D.![]() ![]() |
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