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在平面直角坐标系xOy中，直线l的参数方程为（t为参数），曲线C的参数方程为（θ为参数），以坐标原点为极点，x轴非负半轴为极轴建立极坐标系． （Ⅰ）求C的极坐标方程； （Ⅱ）设点M （2，1），...
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高三下学期数学《》真题及答案
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在平面直角坐标系xOy中若直线l1:s为参数和直线l2:t为参数平行求常数a的值.
选修4﹣4坐标系与参数方程在直角坐标系xOy中直线l的参数方程为t为参数.在极坐标系与直角坐标系xO
在平面直角坐标系xOy中直线l的参数方程为t为参数曲线C.的参数方程为θ为参数.试求直线l和曲线C.
在平面直角坐标系xOy中已知直线l的参数方程为t为参数圆C.的参数方程为θ为参数.若点P.是圆C.上
在直角坐标系xOy中直线l的参数方程为t为参数在以O.为极点x轴的非负半轴为极轴建立的极坐标系中曲线
在平面直角坐标系xOy中直线l的参数方程为k为参数以原点O.为极点以x轴正半轴为极轴与直角坐标系xO
[选修4-4坐标系与参数方程]在直角坐标系xOy中直线l的参数方程为t为参数在极坐标系与直角坐标系x
在平面直角坐标系xOy中以O.为原点以x轴正半轴建立极坐标系曲线C.的极坐标方程为ρ2﹣4ρsinθ
选修4—4坐标系与参数方程在平面直角坐标系xOy中已知曲线C.的参数方程为.以直角坐标系原点O.为极
在平面直角坐标系xOy中已知直线l的参数方程为t为参数圆C.的参数方程为θ为参数.若点P.是圆C.上
在平面直角坐标系xOy中直线l的参数方程为t为参数.以坐标原点为极点x轴正半轴为极轴建立极坐标系圆C
在平面直角坐标系xoy中圆C.的参数方程为t为参数.在极坐标系与平面直角坐标系xoy取相同的长度单位
在平面直角坐标系xOy中直线l的参数方程为t为参数曲线C.的参数方程为θ为参数.试求直线l和曲线C.
选修4—4坐标系与参数方程在平面直角坐标系xOy中已知曲线C.的参数方程为.以直角坐标系原点O.为极
在平面直角坐标系xOy中直线l的参数方程为t为参数曲线C.的参数方程为θ为参数.试求直线l和曲线C.
在直角坐标系xOy中直线l的参数方程为t为参数在极坐标系与直角坐标系xOy取相同的长度单位且以原点O
选修4﹣4坐标系与参数方程在直角坐标系xOy中直线l的参数方程为t为参数.在极坐标系与直角坐标系xO
在平面直角坐标系xOy中直线l的参数方程为t为参数P.Q.分别为直线l与x轴y轴的交点线段PQ的中点
在平面直角坐标系xOy中直线l的参数方程为t为参数曲线C.的参数方程为θ为参数试求直线l与曲线C.的
在平面直角坐标系xoy中已知直线l的参数方程为参数t∈R.同时在以坐标原点为极点x轴的正半轴为极轴建
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已知函数fx=|x+2|+|x﹣2|x∈R． 1若关于x的不等式fx﹣a≥0的解集为R求实数a的取值范围 2若实数ab∈[﹣22]求证|a+b|≤|2+ab|．
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实数a＞b＞0成立的充分不必要条件是
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已知i为虚数单位则复数=
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已知实数xy满足则Z＝的最小值是
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下面定义一个同学数学成绩优秀的标志为“连续5次考试成绩均不低于120分”．现有甲乙丙三位同学连续5次数学考试成绩的记录数据记录数据都是正整数 ①甲同学5个数据的中位数为127众数为120 ②乙同学5个数据的中位数为125总体均值为127 ③丙同学5个数据的中位数为135总体均值为128总体方差为19.8 则可以判定数学成绩优秀同学为
已知F1F2是双曲C=1a＞0b＞0的左右焦点B是虚轴的端点直线F1B与C的两条渐近线分别交于点PQ线段PQ的垂直平分线与x轴交于点M2c0则C的离心率是
党的十八大以来__从全面建成小康社会全局出发把扶贫工作摆在治国理政的突出位置全面打响脱贫攻坚战2018年6月中__国务院关于打赢脱贫攻坚战三年行动的指导意见发布对精准脱贫这一攻坚战做出了新的部署2019年3月十三届全国人大二次会议召开3月7日国务院扶贫办刘永富回答记者问时表示“我国脱贫攻坚取得显著成就贫困人口从2012年的9899万人减少到2018年的1660万人连续6年平均每年减贫1300多万人．并表示“今年再努力一年攻坚克难再减少贫困人口1000万人以上再摘帽300个县左右．” 根据某市所在地区的收入水平消费水平等情况拟将家庭年收入低于1.2万元的家庭确定为“贫困户”该市扶贫办为了打好精准脱贫攻坚战在所辖某县的100万户家庭中随机抽取200户家庭对其2018年的全年收入进行调查抽查结果如下频率分布直方图 1求这200户家庭的全年收人的样本平均值和方差s2同一组中的数据用该组区间的中点值作代表 2由直方图可以认为这200户家庭收入Z近似服从正态分布Nμσ2其中μ近似为样本平均数σ2近似为样本方差s2． i利用该正态分布求PZ＜1.2 ii若从该县100万户中随机抽取100户记X为这100户家庭中“贫困户的数量利用i的结果求EX 附若Z～Nμσ2则Pμ﹣σ＜Z＜μ+σ=0.683Pμ﹣2σ＜Z＜μ+2σ=0.954．
已知集合M＝{y|y＝|x|﹣x}N＝{x|y＝lnx2﹣x}则M∩N＝
已知数列{an}是等比数列若ma且公比q则实数m的取值范围是
Itwasthebiggestnightofmylife一openingnight.Hoursof1anddailyrehearsalshadgoneintothisproduction.Ihadrecitedmylineathousandtimes2thatmyonesentencewouldbethehighlightoftheshow. Asa7﹣year﹣oldboyIwas3toperforminanactualmusical.ThenightbeforeIhad4mycostumeonthebed:awhiteshirtbluejeans?andmyhandmadenecklace. My5wasgoingtobespeciallydone.Mylipswouldbeinbeautifulred.Iwas6preparedtobetheshiningstarinmyclass'sperformanceofthemusicalOneBigHappyFamily. Alittletimebeforetheplaythebackstagewascomplete7.MyfriendandIdressedinourcostumesweregiggling.Childrenwererunningaroundmadly.Somewere8aboutforgettinglines;othersweresingingvarioussongsoutoftune.Itwasabiggroupof9secondgradersabouttomaketheirfirstperformance. Soonthebigmomentcameandweallfiledontothestage10theaudienceofparentsandrelatives.The11beganandmysecondgradeclassstartedsingingwithsweetseven﹣year﹣oldvoices.Isangmylittleheart12hopingtomaketheshowasperfectasI'd13. Myturntospeak!Thekidstandingnexttomehandedoverthemicrophonetome.AsIstartedtospeakInoticedsomethinghadgonehorribly14一themicrophonewasnotturnedon.Thebloodrushedtomyfaceimmediately.15Iturneditoverandswitchedthedeviceon.AftersayingmylineasquicklyaspossibleIhandedthemicrophoneoffandIjustfeltthatIhad16. Everybodyisexcellent!''theteacher17usinthebackstage.I'msorryMissAlex.Isaidtoher.18tobesorryaboutHoney.ShesmiledtomeNoteverysurpriseinourlifeisalwayssopleasant.Youdidagoodjob! Ifeltso19inaminuteandIcanhardlywaittotellmydadandmumthestoryoftheunpleasant20. 1A.experiments B.preparations C.descriptions D.introductions 2A.informed B.confirmed C.amazed D.convinced 3A.eager B.grateful C.scared D.accustomed 4A.laidout B.hungup C.turnedout D.madeup 5A.head B.heart C.hair D.feet 6A.deliberately B.thoroughly C.possibly D.nervously 7A.party B.silence C.tension D.chaos 8A.panicking B.arguing C.greeting D.thinking 9A.relaxed B.timid C.excited D.confused 10A.leaving B.facing C.playing D.greeting 11A.show B.line C.rehearsal D.practice 12A.in B.down C.of D.out 13A.found B.imagined C.declared D.calculated 14A.blank B.wrong C.numb D.mad 15A.Impatient B.Enthusiastic C.Embarrassed D.Determined 16A.pickedup B.mixedup C.cheeredup D.messedup 17A.admired B.criticized C.praised D.taught 18A.Everything B.Something C.Nothing D.Anything 19A.proud B.relieved C.puzzled D.interested 20A.surprise B.lesson C.program D.performance
设a=b=2c=log32则
定义在R上的偶函数fx对任意的实数x有fx+1=﹣fx当x∈[﹣10时fx=﹣x2．若函数gx=fx﹣logax在x∈0+∞上有且仅有三个零点则a的取值范围为．
若实数xy满足则z=x﹣2y的最大值为．
假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文.文中共有10处语言错误每句中最多有两处.错误涉及一个单词的增加删除或修改. 增加:在缺词处加一个漏字符号∧并在其下面写出该加的词. 删除:把多余的词用斜线\划掉. 修改:在错的词下划一横线并在该词下面写出修改后的词. 注意:1.每处错误及其修改均仅限一词; 2.只允许修改10处多者从第11处起不计分. Laughingisoneoflife'smostsimplepleasure.Itisfree.Youcandoitanywhere.Liketheflulaughtercanspreadeasyamongpeople.Oftenwhenwehearsomeonelaughingincrowdedroomorapackedtrainwestartlaughingtoo﹣evenifwehavenoideahow. Infactmentalhealthcanaffectonphysicalhealth.ThereforeLaughteristhebestmedicinedoesnotmeanthatIshouldnottakemedicinewhenyou'resick.Itsimplymeansthathaveapositiveoutlookmighthelpeaseyourtroublesbutmakeyoucheerful.Besidesmakingotherslaughwithyouisalsoanactwhatisjoyfulandkind.
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