21.(12分)已知线段MN的长度为3,其端点M,N分别在x轴与y轴上滑动,动点P满足N2=2PM(1)求动点P的轨迹C的方程:(2)当点M坐标为35】2,0,且点P在第一象限时,设动直线1与C相交于A,B两点,且两直线PM、PB的斜率互为相反数,求直线1的斜率22.(12分)已知函数f)=eΓx+2(1)求f(x)的单调性;(2)证明fx)≥+虹2【A-023】数学试卷第4页(共4页)
17.(本小题10.0分)计算:已知角a的络边经过点P(m2),且e0sa=,求:(1)实数m的值;(2)求cos2a-sin2a+2 sinacosa的值.18(本小题120)分已知桌合A={似y=1 m.xe[.c]},B=片,2,8,C=2m+1xm+(1)求AOB;(2)若BOC=C,求实数m的取值范围.19.(本小题12.0分)已知函数f(x)=log.(5-2x)+log.(x+1),其中0
第四部分写作(共两节,满分35分)第一节短文改错(共10小题;每小题1分,满分10分)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。每处错误仅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(八)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。Last month,our school launched a campaign which intention was to promoteenvironmental protection.The campaign last for one week.Firstly,there was a photo displayto show the seriously pollution caused by human activities.Secondly,there was a lecture on学many small step that we could take in our daily life protect the environment.For example,熔taking the bus and using the bike-sharing system would be a good way.Last but not the least,子we students were encouraging to decorate our classrooms with recycled materials.Throughthe campaign,they have benefited a lot.We realize that it is our responsible to leave a better,cleaner and healthier planet for future generations.烟第二节书面表达(满分25分)你校将举行英语演讲比赛。请你以“Be a Person with Good Manners'”为题写一篇演讲稿够参赛,内容包括:1.阐明礼貌的重要性;閭2.谈谈如何养成有礼貌的好惯。注意:1.词数100左右;2.可以适当增加细节,以使行文连贯。【高三英语第10页(共10页)】·22-02-361C· 信【观察思考】第一个图案中,用了6个球珠,有2个正方形;解第二个图案中,用了9个球珠,有5个正方形;6第三个图案中,用了12个球珠,有8个正方形;10CE 4……【问题解决】PD"CBoA(1)第四个图案中,用了个球珠,有」个正方形;(2)如果用了252个球珠,那么图案中有多少个正方形18.如图,建筑物BC直立于水地面,在其顶端C处测得气球P的仰角P为37°,CP=30m:地面上的点A与建筑物BC相距60m,在点A处测得气球P的仰角为53°.求气球P到地面的距离.(参考数据!re \ssin53°=0.8,cos3°=0.6,tan53°=43七0)PA617722.第18题图五、(本大题共2小题,每小题10分,满分20分)19.如图,直线y=一x+4与坐标轴交于A,B两点,点M(2,m)在直线AB上,点N与点M关于y轴对称.I)当点N在反比例函数y一的图像上时,求的值:8(0,4)(2)当线段MN被反比例函数y=的图像分成两部分,且这两部分长度√MM2,m的比为1:3时,求k的值第19题图20.如图,在四边形ABCD中,∠A=∠D=90°,AD=AB,以BC为直径的半⊙O与AD相切于点E.(1)求证:∠BCE=∠DCE;(2)若CD=√2,求DE的长第20题图六、(本题满分12分)21.甲、乙两个人准备自驾汽车沿一条旅游线路游览.他们收集到以下信息:(不完整)信息一,这条旅游线路上依次分布着A,B,C,D,E,F六个景点,其中A,B.C都被游客评为最美景点,信息二,沿途相邻两个景点间的里程数、汽车的油耗如下表所示:A→BB→CC→DD>EE→F里程(km)40105b油耗(L/km)0.060.080.070.070.062023年“万友”中考模拟卷·数学(一)试题卷第3页,共4页 参考答案点拨:列方程组解应用题7.解:设有x辆车,人数为y人,上月买4斤萝卜2斤排骨共花了34元y=3(x-2),由题意,得今天买4斤萝卜,2斤排骨共花了42元y=2x+9.变式练x=15,解这个方程组,得解:符合安全规定,理由如下:y=39.设均每分钟一道正门可以通过x名学生,一道侧答:有15辆车,39人.门可以通过y名学生,由题意,得8.解:设购买1个温馨提示牌需要x元,1个垃圾箱[x+y=240,需要y元,3x+2×3y=1020.4x+3y=360,依题意,得x=140,y-x=50.解这个方程组,得y=100.x=30,解这个方程组,得∴.5分钟可以通过的学生人数为5×(1一20%)×y=80.(140×2+100×2)=1920(名),答:购买1个温馨提示牌需要30元,1个垃圾箱这栋大楼最多有学生50×8×4=1600(名).需要80元..1920>1600,B组.建造的这4道门符合安全规定.9.D思路点拨:解这个题的实质是列方程组解应用题,思路点拨:设现在儿子的年龄是x岁,现在父亲的关键是抓两个等量关系.先求出每道门每分钟通过y=3x,年龄是y岁,则可列方程组解方的学生人数,再求出5分钟内4道门通过的学生y-7=5(x-7).人数x=14,程组,得设m年后父亲的年龄是儿子的方法总结y=42.2.等量年龄的2倍.则2(14+m)=42+m,解该方程随堂演练即可.A组10.解:设购进甲种节能灯x只,乙种节能灯y只,1.C2.B3.Ax+y=100,由题意,得30x+40y=3300.4.695.246.解:设安排x人加工桌子,y人加工椅子,由题x=70,解这个方程组得意,得y=30.∴.70(45-30)+30(50-40)=70×15+30×(x+y=28,4×3x=2010=1350(元).y.答:该商场售完100只节能灯后,能获利x=10,1350元.解这个方程组,得y=18.思路点拨:先列方程组求出甲、乙两种节能灯的答:安排10人加工桌子,18人加工椅子只数,再求其获利.·19· 周周自测先锋卷(33)测试范围:第十八章18.2-、1.C2.D3.C4.B5.A6.D7.C8.19.C10.C提示:7.连接AC交BD于点O因为四边形AECF是菱形,所以AC⊥BD,AO=OC,OE=OF.又因为E,F为线段BD的三等分 (ii)当-0,符合题意:②当a<0时,因x>0,则e->0,则e'->alnr-a,即c>+lnr-I)a,设m计n-小,则m意生过所以m(x)在(0,1)上单调递减,在(1,+∞)上单调递增.所以m(x)≥m(1)=0,所以,当a<0时,e>0≥+lnr-1)a,即lf(x)l>alnx-a成立,即a<0合题意:③当a>0时,由(1)可知,hx)一a=xe-a,在(0,+∞)上单调递增.又h(0)-a=-a<0,h(a)-a=a(ea-l)>0,所以3xo∈(0,a),使h(xo)-a=xoexo-a=0,iD当x∈(0,o时,xe-a<0,即e-<0,设g)=g-e--alnx+-a>0,则g)=一是一e一-<0,所以g在0,x0上单调递减,所以x∈(0,xo)时,gx)>gxo)=-alnxo-+a:i)当x∈(xo,+∞)时,xe-a>0,即e-8>0,设w)=e-:-alnx+a>0,因为t6=e*+是-是=on-感,Y2令p(x)=x2ex+a-ax,x∈(x,+o),则p'(x)=(x2+2x)ex-a,又令n(x)=(x2+2x)ex-a,x∈(xo,+∞),则n'(x)=(x2+4x+2)ex>0,得n(x)在(xo,+∞)上单调递增.有p'(x)=n(x)≥n(xo)=(x+2x)e*o-a=axo+a>0,得p(x)在(xo,+∞)上单调递增,有p(x)≥p(xo)=x行exo+a-axo=a>0.则t'()=四>0,得t(x)在(x,+∞)上单调递增.则x∈(xo,+∞)时,t(x)≥t(xo)=-alnx0+a.又x∈(0,xo)时,g(x)>g(x)=-alnx0+a,得当a>0时,lf(xl>almx-a时,-alnxo+a>0→0 22.解:(1)f'(x)==1-x-a-0-0'-ae,x<).1分e*1-x (1-x)e*①当a≤0时,f'(x)>0,此时,f(x)在(-o,1)单调递增:.2分②当a>0时,令g(x)=(1-x)2-ae,可以判断g(x)在(-o,1)是减少的注意到:g(-a-1)=(a+2)2-aea-l>(a+2)2-a>0g(I)=-ae<0则必存在∈(-o,l)使得g(x)=0,即(1-x)2-ae。=04分且当x∈(-0,x)时,g(x)>0,于是f'(x)>0,此时f(x)在(-0,x)单调递增:当x∈(x,)时,g(x)<0,于是f'(x)<0,此时f(x)在(x,l)单调递减:…5分(2)当a>0时,令h(x)=f'(x),则:h)=红-16-2》-ae<0于是:了在(-o,)是减少的(x-1)2ex7分对于给定的x2∈(-0,0),令p(x)=f(x+x2)-f(x)-f(x2),2∈(-0,0)则p'(x)=f'(x+x2)-f'(x)因为x+x2 0时,对于给定的x2∈(-o,0),令p(x)=f(x+x2)-f(x)-f(x2),x2∈(-0,0)则p=fx+x)-f(田=1--五-a-1-xae+51-x-x2e*1-x5-e+,11)>0第5页因此p(x)在(-0,0)是增加的于是,p(x)
所以Sn=n.10分18.(本小题满分12分)解:(I)依题意得sinB=sinC+cosCSnC-cosC.2分cosB所以sin Bsin C-sin BcosC=cos Bsin C+cos BcosC,所以sin(B+C)+cos(B+C)=0,4分所以tan(B+C)=-1即tanA=l,5分又因为0
17如国有正方形ACD中,对角线AC,BD相交于点O,点B,F是封角线AC上的两点:且四、(本大超飘2小期,每小角8分,满分16分】AE=CF连接DE,DF,BE,BF求证,四边形DEBF是菱形【解新】证明,:在正方形ABCD中,对扇线AC,BD相交于点O(3分)BDLAC.OB-OD.OA-0CAE-CF,.OA-AE=OC-CF,即OE=OF∴,四边形DEBF是行四边形。又'BD⊥EF,∴,四边形DEBF是菱形.4”(8分18如图,在矩形ABCD中,点E在边BC上点F在BC的延长线上,且BE=CF,求延:∠BAE=∠CDF【解析】证明:,四边形APCD是矩形,∴.AB=CD,∠ABC=∠DCB=90'∴∠ABC=∠DCF=g0.(3分)在△ABE和△DCF中,(AB=DC,∠ABC=∠DCF,BE=CF,∴.△ABE≌△DCF(SAS),∠BAE=∠CDF.…(8分)五、(本大题共2小题,每小题10分,满分20分)19.如图,在△ABC中,∠ACB=90°,D是BC的中点,DE⊥BC,CE∥AD.若AC=2,CE=4,【(1)求证:四边形ACED是行四边形;(2)求BC的长【解析】(I)证明:·∠ACB=90°,DELBC,.AC∥DE又:CE∥AD,.四边形ACED是行四边形.(5分)(2)解::四边形ACED是行四边形,..DE=AC=2.在Rt△CDE中,由勾股定理得CD=√CE-DE=√-=23.,D是BC的中点,.BC=2CD=4√3.…(10分)20.如图,在行四边形ABCD中,CELAD于点E,点F在BC上,且BF=DE.(1)求证:四边形AFCE是矩形;(2)连接EF,若EF∥DC,DE=2,CE=4,求行四边形ABCD的面积【解析】(1)证明:四边形ABCD是行四边形,.AD∥BC,AD=BC.BF=DE,..AD-DE=BC-BF,AE=CF.又,AE∥CF,∴.四边形AFCE是行四边形,CE⊥AD,,∠AEC=90°,.行四边形AFCE是矩形:…(5分(2)解::四边形ABCD是行四边形,【2023年安激中考一轮复卷第动页〔共秘页)】 △A00△AB所以是-品则二=2博r=产2图维的体N√2+Rr【高三数学·参考答案第1页(共7页)】·23-467C·3A=号·栏2=晋h一-2+产2十≥等当且仅当=4时,等号成立9.BD【解析】本题考查圆的方程,考查直观想象的核心素养.由已知得圆C1的圆心C(0,0),半径r1=3,圆C2的圆心C2(3,4),半径r2=4,C1C2|=√(3-0)2+(4-0)2=5,r2-n1 k=1心+ey,…8分令1=ee1,],e+e=h0)=1+},45∈l,2]4<4,)-M)=4+么+宁-4-00.周为1<4s6期4-601->0.tt,因此h)-h)<0,即h) 16.已知菱形ABCD的边长为1,∠ADC=子,将△ADC沿AC翻折,当三棱锥D-ABC表面积最大时,其内切球表面积为四、解答题:本题共6小题,共70分。解答应写出文字说明、证明过程或演算步骤。17.(10分)在△ABC中,角A,B,C的对边分别为a,b,c,已知(b-V3c)sinB+csinC=asinA.(1)求角A的大小:(2)若3D=AC,∠DBC=受,c=6,求△ABC的面积.18.(12分)设数列{an}的前n项和为Sn,且满足Sn=2an+3.(1)求数列{an}的通项公式:(2)证明:数列{an}中的任意不同的三项均不能构成等差数列.19.(12分)在四棱锥P-ABCD中,面PAD⊥面ABCD,ABIICD,AB=2,AD=DC=CB=1,PA=PD=2.(1)设面PAB与面PCD的交线为l,求证:I∥面ABCD;(2)点E在棱PB上,直线AE与面ABCD所成角为若,求点E到面PCD的距离.数学试卷第4页(共6页) 另一个交点在(©,+∞)内,若y=b与y=f(x)和y=g(x)共有三个不同的交点,则其中一个交点为两条曲线y=f(x)和y=g(x)的公共点,记其横坐标为x,令f(x2)=g(x)=f(nx2),则x2∈(1,e),lnx2∈(0,1),记y=b与y=f(x),y=g(x)的三个交点的横坐标从左到右依次为,x2,x4,且满足E<1< - (Text 1)M:Good evening,I booked a room under the name of Tom Smith.I'm ready to check in now.W:OK,I've found it.Checking out on the 27th before 12 noon.Sir,here's your key.Your room is on the 7thfloor and on the left,Room 781.(Text 2)M:Hey,where are you going?W:I left my dictionary in the reading room.I'm going to find it.M:Hurry up!The dorm door is closing.(Text 3)W:Is the football match on now,John?M:No,it begins at 9:00 after the puzzle show.There is a film starting now.(Text 4)W:Excuse me.Do you happen to have change for five pounds?M:I've just used all my change for daily supplies.(Text 5)M:Mum,where shall I put the bowl?W:Here,give it to me.It goes in this cupboard!What's the butter doing in the cupboard?M:I bet Dad put it there.Now give it to me.I'll put it in the fridge.第一节到此结束。第二节听下面5段对话或独白。每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项。听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题将给出5秒钟的作答时间。每段对话或独白读两遍。听下面一段对话,回答第6和第7两个小题。现在,你有10秒钟的时间阅读这两个小题。(Text 6)W:Hi,Jack!What's the matter??Wake up!M:I stayed up late last night.My friend had a party.I only slept for about four hours.W:Why didn't you stay in bed this morning?M:I have to meet my study group in the library.We'll have a big test next week.W:A big test?I have read a report.It says that if you don't get enough sleep after you study,you may forget30%of what you've studied!听下面一段对话,回答第8和第9两个小题。现在,你有10秒钟的时间阅读这两个小题。(Text 7)W:So,are you still living with your parents?M:Yes,but I wish I had my own apartment.W:Why?Don't you like living at home?M:No.My parents are always asking me to be home before midnight.I wish they'd stop worrying about me.W:Yeah,parents are always like that.M:And they expect me to help around the house.I hate housework.I wish life weren't so difficult.W:So,why don't you move out?M:I wish I could,but I don't have much money and I don't want to work hard.Where else can I get free roomand food?W:Hey,you should depend on yourself.【高三英语·参考答案第2页(共4页)】·23-323C· 【答案】A【解析】1422-312-7+1【分析】因为5,所以构造函数()=lmx-2(x-1)x+1(x>0),利用导数别断单调性,可得,令8=-5血,e宁,利用导数别撕单调,可得a>c7143127【详解】因为所以设+x>0,)=2x+----y/(x)=Inx-2(x-1)(x+1)2x(x+1)2≥0.所以f)在(0,+o)上为增函数,722-0I所以3>10=051+7>07171ln->0 In-所以,所以53,即53,所以b>a.令8(0=x-sinx,xeo2x0,g(x)=1-cosx≥0,所以8g(x)=x-sinx在上为增函数,所以3宁>80=01sin>01、11sin,所以33,即33,所以a>c,综上所述:b>a>c.故选:Af()=lnr-2x-1)【点睛】关键点点睛:构造函x+1(x>0),g(x)=x-sinx.xe10.7),利用导数判断单调性,根据单调性比较大小是解题关键二、多项选择题(本大题共4小题,每小题5分,共20分在每小题给出的四个选项中,有多项符合题目要求,全部选对的得5分,选对但不全的得2分,有选错的得0分)9.若a>b,则()第5页/共25页 解得x∈[-2+2kπ,2km],k∈Z6分②f(a+8g)=2sina+1=号,sin-年51因为a∈(0,),所以cosa=V1-sin2a-3,..8分因为B∈(0,受),所以a-B=(-号),所以cos(a-)=V1-sin2(a-历=是5.10分所以sin(2a-B)=sin[(a-B)+a]=sin(a-β)cosa+cos(a-B)sinc=-×+品×=-6512分20.某地区为了解市民的心理健康状况,随机抽取了位市民进行心理健康问卷调查,将所得评分(百分制)按国家制定的心理测评评价标准整理,得到频率分布直方图.已知调查评分在[70,80)中的市民有200人.心理测评评价标准调查评分[0,40)[40,50)[50,60)[60,70)「70,80)[80,90)90.100心理等级E◇C(1)求n的值及频率分布直方图中t的值:(2)该地区主管部门设定预案:若市民心理健康指数的均值不低于075,则只需发放心理指导资料,否则需要举办心理健康大讲堂.根据调查数据,判断该市是否需要举办心理健康大讲堂,并说明理由.(每组的每个数据用该组区间的中点值代替,心理健康指数=调查评分÷100)(3)在抽取的心理等级为D的市民中,按照调查评分的分组,分为2层,通过分层随机抽样抽取3人进行心理疏导.据以往数据统计,经心理疏导后,调查评分在[40,50)的市民的心理等级转为B的概率为4,调查评分在50,60)的市民的心理等级转为B的概率为3,假设经心理疏导后的等级转化情况相互独立,求在抽取的3人中,经心理疏导后恰有一人的心理等◆频率级转为B的概率;组氍0.035【答案】(1)由已知条件可得n=200=1000,1分0.02×100.025又因为每组的小矩形的面积之和为1.0.020所以(0.035+0.025+0.02+0.004+8t)×10=1,解得t=0.002;.3分0.004405060708090100分第9页,共12页频率分布直方图 所以g(x)=3x2+6.x在[1,十0∞)上的最小值为g(1)=9,…10分所以a≤9,故a的取值范围为(一∞,9].…12分(方法二)因为f(.x)在[1,十o∞)上单调递增,所以f(x)=3.x2+6.x-a≥0对x∈[1,十o∞)恒成立。…7分因为f(x)=3x2十6x一a在[1,十o∞)上单调递增,…9分所以f(x)在[1,十o∞)上的最小值为∫(1)=9-a,…10分所以9-a≥0,…11分即a≤9,故a的取值范围为(一0∞,9].…12分20.解:(1)设该三棱柱形实木块的高为hcm,则由该三棱柱形实木块的所有棱长之和为60cm,【高三数学·参考答案第3页(共5页)】·24-20C·得6.x十3h=60,即2x十h=20,…2分则h=20-2x.…3分由8061o4分所以V=h=g2(20-2)=(10r2-)0 - 21(本题满分12分)双曲线C君若=1(a>0,620)的左原点为A,焦距为4,过右焦点F作垂直于实轴的直线交C于B,D两点,且△BD是直角三角形.定志(1)求双曲线C的方程;之1krk-之%,k,2(2)M、N是C右支上的两动点,设直线AM、AN的斜率分别为k1,k2,若点k,=一2,求点A到直线MN的距离d的取值范围,吹化)2c1)C2k,k,-2没lw:y”、%1+2(x11)1×川可功3(2m刊y+n1yt2可@2轴→ny+6mny+n)DA入0:Bn-1)lm)-I2m'n (nt/)+2nttm')发m,y)NX,)n2(6n2-6)-m'(2n+/2njtm'(m4mt6>/,为:应暖小消3m215,k》n-53m-22.(本题满分12分)已知函数f(x)=ax2+lnx.(1)讨论函数f(x)的单调区间;(2)当>0时,f)>2x+x+1-e+nx恒成立,求实数a的取值范围。f:0xx,X>2)X)0,fx)2x3txf村~e'flnx恒月:26x+时'tn*zx'tX+l-efn①久0Aixtxt-efN,f)0X'Xf)在(o,加)L单增)餐h:4*对e,)KmrXAx)(x0>09(x):3x43-(xt3)e"70x)无,m,L草傍NX-1xt切附对:-1x+Y)R<0)3")右,+Bacs 2af2+19o1.9电必以还流小<9)左10,1w)上 or pedestrianised(使,Wht de Rachel cal n poled?people see,they genA.Make dresses using new material.just see the car's higB.Share skills about making clothes.飞8 What doC.Donate whatever they no longer use.A.Making it intoD.Care for and respect the children in need.B.Getting a drivi7.What qualities can we learn from Rachel O'Neill?C.Being involvecB.Diligence and sincerity.A.Fairness and honesty.D.Owing a homeD.Determination and modestyC.Kindness and devotion.实2 What leA.Some socialGetting a driving license was once a universal passage into adulthood.But now a growing mi-C.Environmentnority of young people ignore or actively oppose it,into their 20s and beyond.That starts to createmore support for anticar policies in cities around the world to pass anti-car laws,changing plan-A10.What doe.thening rules to favour pedestrians over drivers.After a century in which the car remade the richA.Agrees witD11.What does thworld,the tide begins to swing the other wayBy 1997,43%of America's 16-year-olds had driving licenses.But the proportion has beenA.People arefalling for every age group under 40.Even those who have them are driving less.A similar trend isB.Banningseen in Europe.One study of five European capitals found the number of driving trips made byC.It's hardworking people was down substantially since a peak in the 1990s.D.Anti-carNo one is entirely sure why young adults are proving resistant to owning a car.The growth ofthe internet is one obvious possibility-the more you can shop online,or stream films at home,A recentthe less need there is to drive into town.The rise of taxi apps like Uber has contributed as well.(ZSL)showsDriving generally is more expensive.Other reasons seem more cultural.One big motivator is wor-The Liviries about climate change.port tracks thThe falling popularity of cars among the under-40s chimes with the mood among city plan-population heners and urbanists.In America,New York has banned cars from Central Park and some streets.Inarea(or thethe past few years,dozens of American cities have removed rles that force developerstoprovideThe rea cerin amount of free parking around their buildings.These inclucAs the example in Oxford shows,political opposition could put the brakes on the growth offound in 31ni-rparts of Erope where nti-c police have been in place,theyap-Thispear to have worked.Ciulio note that almost nowhere in the world that has removed a bigroadfrom 1970精品押题卷·英语五第4页(共10页) 截屏已完成点击查看che,子。之家、特®⑦ 【答案】ABD【解析】(x)=Ix)【分析)构造函数x,利用导数运算公式求出函数()的解析式,由此可得函数f(x)的解析式,再血导数与函数的单调性,极值及最值的关系判断各选项.【详解】设8()g()=r(f-nx+1x,则所以8(x)=xInr+C(C为常数),所以f()=g(x)=x2nx+Cx又f(0)=0,所以C=0,所以f(x)=rInx,f()=x(2lnx+1)0sx<当VE时,(x)水0,f()单调递减,1x>当时,)>0,()单调递增,1x=所以(x)在E处取得极小值,111因为1<<2,所以2E所在上有极小值可知A,B都正确g(x)=xInx g'(x)=Inx+10 数学周刊参考答案第3期人教八年级3版因为s+8,所以m+6m+8mi+6m+5(m246m+9,(3)原式=(9xy3-27xy2)÷9x2y2=y-3x.17.(8分)解:根据题意,得(5ax3ax)÷(x30x)=15ax2:化简得m+6m=1.所以S,=m2+6m+9=1+9=10.第十四章整式的乘法与因式分解(14.1.4)同步诊断30所以至少应该明买7块这样的塑料扣板。一、选择题(每小题4分,共32分)1.A2.D3.A4.B5.D6.C7.A8.D当a4时4-8二、填空题(每小题4分,共24分)所以当a=4时,购买的扣板为8块.9.a2610.g11.9ab212.(ab-2a-2b+4)18.(12分)解:(1)a2+3ab+2b(2)拼成的图形如图所示.13.-2414.-3aa2三、解答题(共44分)15.(每小题4分,共12分)解:(1)原式=a.(-2ab)=-2ab;(2)原式=-3x4-6x3+9x2;(3)原式=3a2-ab+3ab-b2-(4u2+2ab-2ab-b2)=3a2+2ab-b2因为2(2a+b)(a+b)=4a2+6ab+2b2=60,a+b=5,所以2a+b=4a2+b2=-a2+2ab.60÷2÷5=6.16.(每小题4分,共12分)解:(1)原式=36ab÷3b=12ab:(3)因为(4a+7b)(6a+5b)=24a2+62ab+35b2,所以x=24,y=(2)原式=3x2-4x35,=62.所以x+y+z=24+35+62=121. 05101520323P105102020所以X的数学期望E(X)=0×3+5×2+10×+15×3+20x-25=6253」211051020204所以使用电辅式太阳能热水器一天节省的电量为20-6.25=13.75(千瓦时).20.如图,在△ABC中,点D在边AB上,BD=2AD,∠ACD=45°,∠BCD=90°DB(1)求证:BC=√2AC;(2)若CD=3求SABC【答案】(1)证明见解析2【解析】【分析】(I)由正弦定理得到AC=√2AD·Sin∠ADC,再由锐角三角函数得到BC=BD·sin∠BDC,最后由诱导公式计算可得:(2)设CA=x,根据面向量的线性运算得到CD=2CA+CB,再根据数量积的运算律及定义得到方程求出x,最后由面积公式计算可得【小问1详解】在△ACD中,∠ACD=45°,由正弦定理可得ACADsin∠ADC sin∠ACD'AD·sin∠ADC所以AC=AD.sin.∠ADC=2-=√2 AD.sin∠ADC'sin∠ACD在△BCD中,∠BCD=90°.则BC=BD·sin∠BDC,由于∠BDC+∠ADC=π,BD=2AD,所以BC=BD·sin∠BDC=2AD·sin(π-∠ADC)=2 ADsin∠ADC=√2AC,即BC=V2AC.第15页/共19页 l®田O845%☐☐109:45〈辽宁丹东高三上(11月)数学试题+答案.pdf按秘密级事项管理丹东市2024届高三总复阶段测试数学试题参考答案一、选择题1.C2.A3.D4.B5.D6.B7.B8.A二、选择题9.BD10.BCD11.ACD12.ABC三、填空题三13.414.36·16四、解答题17.【改编自B版教材选择性必修三P98页例2】(1)解:因为f(x)的定义域为R,所以∫'(x)=x2-m,当m≤0时,f'(x)≥0,则f(x)在R上递增,当m>0,解不等式x2-m>0,得x<-√m或x>√m,,此时fx)递增,解不等式x2-m<0,得-√m 10.【解折】因为f)=-名,定义域为xeR,f-=:2--2=f,所以为偶x2+2(-x)2+2x2+2函数,所以f(x)的图象关于y轴对称,故A错误,B正确;令t=x2+2(t>2),当x∈(0,+o)时,1=术+2单调递增,当x在(o0)时,1=+2单调递减,而)=1-,在2切)单调递增,所以由复合函数单调性可知f(x)在(0,+o)单调递增,又f(x)为偶函数,所以f(x)在(-o,0)单调递减,故C错误:因为y='片1-兰,由>2,有0<<2,所以-2-4<0;故-131-2<1,即y∈[-1,I),故D正确,故选:B,D.11.【解析】由题意可知,函数过点(1,1)和点(3,4),代入函数关系式:y=kd(k∈R,且k≠0;a>0,(ka=14”解得K),函数送系武为y×2=2·由2-2=2不是常数,且a≠),得a=2知浮萍每个月的面积不等,故A错误;当x=6时,y=2=32,浮萍的面积超过了30m2,故B正确;令y=2时,2=2-1→4=2,令y=64时,64=2-1→12=7得:42-4=5;所以C正确,令y=4得:4=3:令y=6得:12=log212;令y=9得:4=log218,∴.4+4=3+log218=log2144=21og212=212,故D正确.故选:BCD.12.【解析】对于A:若y=f(x)是偶函数,则f-x)=f(x),若1f(x)-f(x,)川≥g(x)-g(x)川对任意x、x2∈R恒成立,令x=x,x2=-x,则|f(x)-f-x)川≥g(x)-g(-x)川,因为f(-x)=fx),所以|g(x)-g(-x)川≤0,所以g(x)=g(-x),所以函数y=g(x)也是偶函数,故A正确。对于B:若y=f(x)有最大值和最小值,因为|f(x)-f(x)川≥g(x)-g(x)川,则(x)-f(x)川最小值≥g(x)-g(x,)川最大值,所以y=8(x)不一定有最大值或最小值,故B不正确。对于C:设x graph probably mean?
A.Deny.
B.Prove.
C.Understand.
D.Examine.
27.What is the bad effect of offering children too much?
A.Parents possibly get mentally tired.
B.Children are unable to make full use of them.
C.Children will less likely succeed in the future.
D.Parents are likely to ask too much of their children.



