您所在的当前位置：高中数学试题 >

均值不等式

> △ABC满足，∠BAC=30°，设M是△ABC内的一点(不在边界上)，定义f(M)=(x,y,z)，其中分别表示△MBC，△MCA,△MAB的面积，若，则的最小值为__________________

问题：

发布时间：2024-09-10

△ABC满足，∠BAC=30°，设M是△ABC内的一点(不在边界上)，定义f(M)=(x,y,z)，其中分别表示△MBC，△MCA,△MAB的面积，若，则的最小值为__________________

参考答案：

提问用户：90***JAb

可能感兴趣的题目：

1 完形填空 Blind from birth,I have never had the opportunity to see myself and have been completely dependent on the image I create in the eyes of others. There are those who __ 1__ that since I can"t see,I obviously also cannot __ 2__.Very often people will talk with me at the top of their lungs.Conversely to this,people will also often __ 3__ ,assuming that since my eyes don"t work,my ears don"t either.For example,when I go to the airport and ask the ticket agent for __ 4__to the plane,he or she will always pick up the phone and call a ground hostess in a very low voice."Hi,Jane,we"ve got a 76 here." I have concluded that the word " __ 5__ " is not used because they are unwilling to inform me of my condition of which I may not have been previously __ 6__. On the other hand,others know that of course I can hear,but believe that I can"t talk.Once I became ill and was hospitalized.Immediately after I was __ 7__ ,I was wheeled down to the X－ray room.Just at the door sat an elderly woman(judging from her voice) asking the orderly(护工) who had been wheeling me:" What is your name?" "What"s your name?" The orderly __ 8__ to me."Harold Krents",I replied."Harold Krents",he repeated."When was he born?" "When were you born?"…This continued for about five minutes before I finally interrupted,"Look,this is absolutely __ 9__.OK,I can"t see,but it"s become pretty__ 10__ to both of you that I don"t need an interpreter(翻译). " "He says he doesn"t need an interpreter," the orderly reported to the woman. The __ 11__ misconception of all is the view that because I can"t see,I can"t __ 12__.I was turned down by over forty law firms, __ 13__ my qualifications included a cum laude degree from Harvard Law School.The __ 14__to find jobs,the continuous __ 15__of being told that it was impossible for a blind person to__ 16__law,the rejection letter,not based on my lack of __ 17__but rather on my disability, will always remain one of the most upsetting experiences of my life. __ 18__,the Department of Labor issued laws that demand equal __ 19__ opportunities for the disabled.The business community"s response has been __ 20__.The attitude towards the disabled is beginning to change. ( )1. A. assume ( )2. A. hear ( )3. A. shout ( )4. A. welcome ( )5. A. passenger ( )6. A. afraid ( )7. A. invited ( )8. A. asked ( )9. A. cheerful ( )10. A. clear ( )11. A. earliest ( )12. A. think ( )13. A. as if ( )14. A. attempt ( )15. A. disappointment ( )16. A. disobey ( )17. A. confidence ( )18. A. Regretfully ( )19. A. medication ( )20. A. enthusiastic B. observe B. talk B. laugh B. permission B. blind B. aware B. released B. responded B. ridiculous B. easy B. slightest B. study B. even though B. opportunity B. relief B. challenge B. luck B. Deliberately B. employment B. passive C. approve C. feel C. whisper C. advice C. trouble C. curious C. included C. repeated C. charming C. confusing C. latest C. work C. now that C. mistake C. envy C. practice C. ability C. Exactly C. learning C. negative D. propose D. care D. cry D. assistance D. situation D. desperate D. admitted D. exchanged D. disgusting D. doubtful D. toughest D. understand D. in case D. success D. effort D. make D. ambition D. Fortunately D. traveling D. uncertain
2 第二节读写任务(共l小题，满分25分) 阅读下面的短文，然后按照要求写一篇150词左右的英语短文。 Friendship with oneself is all important, because without it one cannot be friends with anyone else in the world. We often focus on building relationships with others that we forget the essential first step: being friends of ourselves. That is the crucial first step if we are to have good relationships with others. How can we have good relationships with others if we don’t even have good relationship with ourselves? Here are some tips: 1. Forgive yourself You may have made those mistakes in the past, but is there anything you can do about them? I don’t think so, except learning from them. It’s true that you are not perfect, but neither is everybody else. It’s normal to make mistakes, so do yourself a favor by giving yourself forgiveness. 2. Focus on your strengths Instead of focusing on your weaknesses, focus on your strengths. You always have some strengths which give you a unique combination nobody else have. Recognize your strengths and build your life around them. 3. Stop comparing yourself with others You are unique. You can never be like other people, and neither can other people be like you. The way you measure your success is not determined by other people and what they achieve. Instead, it is determined by your own life purpose. You have everything you need to achieve your life purpose, so it’s useless to compare yourself with others. [写作内容] 假设你的同学总觉得自己学习不如别人，因而产生自卑心理，请你写根据上面所提供的材料写一篇短文,用E-mail 发给他(她)： 1．以约30个词概括文章大意，说明首先要对善待自己的观点； 2．以约120个词表达你对他(她)的建议和希望，并包括如下要点： (1) 分析他(她) 产生自卑心理的原因； (2) 找出他(她)的优势； (3) 提出合理建议。 [写作要求] 1．作文中可使用自己的亲身经历或虚构的故事，也可以参照阅读材料的内容但不得直接引用原文中的句子； 2．文中不能出现真实姓名和学校名称； 3．文章开头和结尾已写好。 [评分标准] 概括准确，语言规范，内容合适，篇章连贯。 Dear Li Ping, I’m glad that you trust me so much and tell me your true feeling, now I’ve read an article which says that _____________________________________________________________________With the best wishes! Yours truly， Wang Yan
3 依据元素周期表及元素周期律，下列推断正确的是 [ ] A．H 3BO 3的酸性比H 2CO 3的强 B．Mg(OH) 2的碱性比Be(OH) 2的强 C．HCl、HBr、HI的热稳定性逐渐增强 D．若M +和R 2-的核外电子层结构相同，则原子序数：R>M
4 创建于清康熙八年（1669年）的北京同仁堂是中药行业著名老字号。1954年同仁堂响应国家号召，顺利实现了公私合营。公私合营出现在 A．土地改革运动时期 B．三大改造时期 C．文革时期 D．改革开放时期
5 下列各句中没有语病的一句是 A．无量藏泉是来自香格里拉的健康好水，是全球唯一的天然小分子活水，这种水有6大神奇功效：能护肤，能改善前列腺炎，能解酒、加强排毒，能改善通风，能降低血粘度等。 B．数学发展的这幅素描，尽管简略，但却表明数学的生命力正是根植于养育她的文明的社会生活之中。 C．天还没亮，敌人的先头部队就已经来到了村口，眼看一场灾难就要发生，由于一只小狗的惊叫，才使得20多人及时逃生。 D．根据现有法律规定，对于诉讼欺诈行为一般只给予训诫、罚款、和拘留的措施，这让那些制假、售假者有了可乘之机。
6 如图甲所示，在两极板a、b之间有一静止的电子，当在a、b之间加上如图乙所示的变化电压时（开始时a板带正电），电子的运动情况是（不计重力，板间距离足够大）（　　） A．电子一直向a板运动 B．电子一直向b板运动 C．电子在两板间做周期性往返运动 D．电子先向a板运动，再返回一直向b板运动
7 Some of the students have already learned enough French to________a conversation with a native French speaker. [ ] A．carry on B．keep on C．go on D．hold on
8 已知函数若，使得成立，则实数的取值范围是 A． B． C． D．或
9 下列物质性质变化规律正确的是 [ ] A．金属Na、Mg、Al的硬度依次降低 B．HI、HBr、HCl、HF的沸点依次降低 C．干冰、钠、冰的熔点依次降低 D．O、F、H的原子半径依次减小
10 甲乙两队参加奥运知识竞赛，每队3人，每人回答一个问题，答对者为本队赢得一分，答错得零分。假设甲队中每人答对的概率均为，乙队中3人答对的概率分别为且各人正确与否相互之间没有影响.用ε表示甲队的总得分. （Ⅰ）求随机变量ε分布列； (Ⅱ)用 A表示“甲、乙两个队总得分之和等于3”这一事件，用 B表示“甲队总得分大于乙队总得分”这一事件，求 P( AB).

△ABC满足 ，∠BAC=30°，设M是△ABC内的一点(不在边界上)，定义f(M)=(x,y,z)，其中 分别表示△MBC，△MCA,△MAB的面积，若 ，则 的最小值为__________________

可能感兴趣的题目：

△ABC满足，∠BAC=30°，设M是△ABC内的一点(不在边界上)，定义f(M)=(x,y,z)，其中分别表示△MBC，△MCA,△MAB的面积，若，则的最小值为__________________