1 . 已知
是同一平面内的三个向量,
.
(1)若
为单位向量,且
,求
的坐标;
(2)若
,且
与
垂直,求
与![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
夹角
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e12e95f703ad30ab9a3d38376830989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b981b38133d5d65060dd8ff4d65a66be.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a0b19e69be46452425916a0fcb49c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5dd43c3c9a578b91fe832c4c2477103c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a0b19e69be46452425916a0fcb49c9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a09bede8bcb942fc0a17b8300cfa47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/437dc907211c5934f938d869f6b19e93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c67a5673958e175b00200a75e645c73c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://img.xkw.com/dksih/QBM/2024/4/25/3483210128482304/3523740179324928/STEM/c75277594e5341938380bceb0f145b6a.png?resizew=14)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
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解题方法
2 . 记
的内角
的对边分别为
,且
.
(1)求
;
(2)若
,
的面积为
,求
的周长
![](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/9b11d83cc4abd3886788064b177a46c4.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f5b763032c085a1e60822d8dc1b3605.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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3 . 如图,在平面四边形
中,已知
,
,
,
为线段
上一点.
的值;
(2)若
为线段
的中点,求
的值;
(3)试确定点
的位置,使得
最小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a4625de335e4a20dcddd5b5b62bf60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a20a2e8baa81c2a04751a1515229cc24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de87e3d243ee1237c32c217f2c684159.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5b3890656c60e7a27885d0c8dcb5d12.png)
(3)试确定点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5b3890656c60e7a27885d0c8dcb5d12.png)
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解题方法
4 . 如图,在四棱锥
中,四边形
为正方形,平面
平面
,
是边长为2等边三角形,点
分别为
的中点,点
为线段
上一点(包括端点).
为线段
的中点,求平面
和平面
夹角的正弦值;
(2)当直线
与平面
所成的角最大时,求出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177678001b2ccde1db8f57fa5e017002.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d730ceac3b62e43c6a2761c3754479c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6612c697aa43a72115e5dce1106c0557.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc46688d8723cf2003fc25890265200.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
(2)当直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc46688d8723cf2003fc25890265200.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad0d6d600e2676abc87e05cde8aebc1a.png)
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5 . 已知函数
.
(1)若
,求函数
在区间
上的最大值;
(2)若对于任意的
,
,都有
,则实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9081e6e87a3830131d082a9897ccdbf6.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/127064e45dfb9edf8bd87cf8070db141.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/028517e8bebe634441e0a5c79828e88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e172d6c98d590a947d85b6969a8f8785.png)
(2)若对于任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7229d6b13f2fa64dbc2221dba5be9672.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33bd24e647a626899a243a3f3984f90a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/998300a677c3f657523a4071def9135a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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6 . 某商场为促进消费,规定消费满一定金额可以参与抽奖活动.抽奖箱中有2个蓝球和2个红球,这些球除颜色外完全相同.有以下两种抽奖方案可供选择:
(1)若顾客选择方案A,求其所获得奖池金额X的分布列及数学期望;
(2)以获得奖池金额的期望值为决策依据,顾客应该选择方案A还是方案B?
初始奖池 | 摸球方式 | 奖励规则 | |
方案A | 30元 | 不放回摸2次,每次摸出1个球. | 每摸出一个红球,奖池金额增加50元,在抽奖结束后获得奖池所有金额. |
方案B | 有放回摸2次,每次摸出1个球. | 每摸出一个红球,奖池金额翻倍,在抽奖结束后获得奖池所有金额. |
(1)若顾客选择方案A,求其所获得奖池金额X的分布列及数学期望;
(2)以获得奖池金额的期望值为决策依据,顾客应该选择方案A还是方案B?
您最近一年使用:0次
名校
7 . 坛子里放着5个大小,形状都相同的咸鸭蛋,其中有3个是绿皮的,2个是白皮的,如果不放回地依次拿出2个鸭蛋.
(1)求第1次拿出绿皮鸭蛋的概率;
(2)在第1次拿出绿皮鸭蛋的条件下,求第2次拿出绿皮鸭蛋的概率.
(1)求第1次拿出绿皮鸭蛋的概率;
(2)在第1次拿出绿皮鸭蛋的条件下,求第2次拿出绿皮鸭蛋的概率.
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8 . 从①
;②
;③
, 这三个条件中任选一个, 补充在下面问题中, 并加以解答.
在
中,三边
分别是角
的对边, 若______.
(1)求C;
(2)若
,求
的面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d8447a2411972b1375712e3c28cdca6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65d983612b3c1977916dd721d3413bce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50ad4300ec11d8da30369d44a3cdf07d.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e5ba3badffe942dcfb60da88629e7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e70100bd019ce2be544ccd266318b0bd.png)
(1)求C;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6de1d395e6c48c0676a1488a299479d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf59f210a4f3916022847a4fd61b6ed.png)
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9 . 已知
中,角A,B,C对应边分别为a,b,c.
(1)求证:
;
(2)已知
.
①若
,求A;
②若
是锐角三角形,且
,求
周长的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8df60d8ae1e87ccc51be55f99b01f3b9.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b19988d792b5252222f0a7acf7ef5fd.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3578b63c5903089595bf324c809a997c.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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10 . 某市高一年级数学期末考试,满分为100分,为做好分析评价工作,现从中随机抽取100名学生成绩,经统计,这批学生的成绩全部介于40和100之间,将数据按照
,
,
,
,
,
分成6组,制成如图所示的频率直方图.
(2)若成绩在
的为A等级,
的为B等级,其他为C等级,
①在这100名学生中用分层抽样的方法在A,B,C三个等级中抽取25人,求从B等级中抽取的人数.
②以样本估计总体,用频率代替概率,从该市所有参加考试的高一年级学生中随机抽取3人,求至少有一人为B等级的概率.(注:当总体数比较大时,不放回抽取可视为有放回抽取)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64fc138be9688253cbdeae2808eb74ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/486c7705dbd7b7b9ec5dd17b4891088b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea146d8ec45e63ad14683fd31064de66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e77699e3d1ddc6e698a640573a7ef787.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d90faf85d1548242098a6fe3accd84f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef1a32a9f2b04fc931c6a0da0b7485e2.png)
(2)若成绩在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef1a32a9f2b04fc931c6a0da0b7485e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c391d1ca31fa5f2b6de158bb3b47791.png)
①在这100名学生中用分层抽样的方法在A,B,C三个等级中抽取25人,求从B等级中抽取的人数.
②以样本估计总体,用频率代替概率,从该市所有参加考试的高一年级学生中随机抽取3人,求至少有一人为B等级的概率.(注:当总体数比较大时,不放回抽取可视为有放回抽取)
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