解题方法
1 . 如图,在多面体
中,
平面
,四边形
是正方形,
.
与平面
所成角的余弦值;
(2)证明:
平面
;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9bf53e97203aa720fe3a09b9bf534af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe240da6d51d3efea02af13e73b87ab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a9fd76d8997e3b2db7d9cb9b72d0f80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2e30e6cd7e777ccd3edb50a9bd3163c.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db807b09cc550f476b3f8fa0c6a14425.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ca19321c6776be24e4be5033b60ed7.png)
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2 . 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
3 . 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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4 . 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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5 . 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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名校
解题方法
6 . 已知
的二项展开式共有
项,完成以下问题:
(1)求展开式中二项式系数之和;
(2)展开式中是否存在常数项,若有,请求出常数项;若没有,请说明理由;
(3)求展开式中的系数最大的项.
(注:结果用数字作答)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0aeb06e83f61a7ef145ef65cdcd0e70c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5453184e251cfe787b5965cd38426962.png)
(1)求展开式中二项式系数之和;
(2)展开式中是否存在常数项,若有,请求出常数项;若没有,请说明理由;
(3)求展开式中的系数最大的项.
(注:结果用数字作答)
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7 . (1)一排10个空位,四人就坐其中的4个位子.若6个空位中,4个相连,另2个也相连,但6个不连在一起,有几种坐法?
(2)为了某次的航天飞行,现准备从10名预备队员中选4人参加航天任务.若选四个航天员分配到A、B、C三个实验室去,其中每个实验室至少一个航天员,共有多少种选派法?
(3)已知从1,3,5,7,9任取两个数,从0,2,4,6,8中任取两个数,组成没有重复的数字的四位数,可以组成多少个四位偶数?(注:结果用数字作答)
(2)为了某次的航天飞行,现准备从10名预备队员中选4人参加航天任务.若选四个航天员分配到A、B、C三个实验室去,其中每个实验室至少一个航天员,共有多少种选派法?
(3)已知从1,3,5,7,9任取两个数,从0,2,4,6,8中任取两个数,组成没有重复的数字的四位数,可以组成多少个四位偶数?(注:结果用数字作答)
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名校
8 . 已知
,
.
(1)解关于x的不等式
;
(2)若
是方程
的两个实数根,且
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef2eb4185432994d8037ef5b05a6009a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
(1)解关于x的不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/018857ec6e498113b3b12a730d9313da.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce7ae90d808f05e86ea063238e4b2f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ffbd6d46c75b7454cc1259ed8d818ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b921b1d9cbc9bad8cc999e13e747517f.png)
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9 . 某运动服装品牌店将购买次数超过五次的会员称为星级会员,其他会员称为普通会员
该店随机抽取男、女会员各
名进行调研统计,其中抽到男性星级会员
名,女性星级会员
名.
(1)完成下面的
列联表,并依据小概率值
的独立性检验,是否可以认为星级会员与性别有关![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82bbee662e242611afdbdae4b8a36a7c.png)
附:
,其中
.
(2)该运动服装品牌店在今年店庆时将举办会员消费返利活动,活动有如下两种方案.
方案一:店内商品一律九折优惠;
方案二:会员可参加摸奖游戏,游戏规则如下:从一个装有
个白球、
个红球
个球除颜色外其他均相同
的箱子里,有放回地摸三次球,每次只能摸一个球
若三次都没有摸到红球,则无优惠
若三次摸到
个红球,则获得九折优惠
若三次摸到
个红球,则获得八折优惠
若三次摸到
个红球,则获得七折优惠.
哪种方案对会员更有利
请说明理由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0efba7147f5b9ced8bc4a72f0a9fb8af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06fc7811f9525e8b8c833746d6af5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b72ac611ae66b86761e080761d9aabc.png)
(1)完成下面的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead9d6ff51996f3ebace6f212e11a9e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82bbee662e242611afdbdae4b8a36a7c.png)
男性会员 | 女性会员 | 合计 | |
星级会员 | |||
普通会员 | |||
合计 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2187714e660234f0b72f2b47d3ea685a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
方案一:店内商品一律九折优惠;
方案二:会员可参加摸奖游戏,游戏规则如下:从一个装有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e4f1701733f0a47f8991c0c277f8f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac8c94316312f093ebfc80b872a83c25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ca6fa9955690cec01db601e3abce0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ca6fa9955690cec01db601e3abce0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ca6fa9955690cec01db601e3abce0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
哪种方案对会员更有利
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82bbee662e242611afdbdae4b8a36a7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
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10 . 如图,在
中,
,
为
的中点,
与
交于
点
设
,
.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97202521b8a0fafa6cd5bef52620a8c6.png)
(2)试用
表示
;
(3)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8945281a44657d65731ee7bebffa0ac5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7b9d8a08fc52c31cc1a7f527d18b55c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f386f5b56b07b96f2600da1be15414a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97202521b8a0fafa6cd5bef52620a8c6.png)
(2)试用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b172cf8d898883d82e973f28c3c3a3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2caf2e65bebc1523f8e89b59a90f2ab.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231ca1d2eef7dc64d75d713ea3335c21.png)
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