R数学少反思领悟系数和问题常用“赋值法”求解项的系数的最值问题赋值法是指对二项式中的未知元素赋值,从而求。2】已知近十二的展开式的二项式系二项展开式的各项系数和的方法,求解有关形威和比(8:一少”的展开而二项式系数和大型(2)在科目二与科目三的考试中,每次考试都有两次机会,若第一次没有通过,则可以进行第二次考试要求]1.考试,第二次考试不通过,则需要过10天后进行补考,根据常的模拟考试,小赵每次通过科国件的并、交与互二的概率为Q.7,每次通过科目三的概率为0,8,日每次是否通过互不影响.记小赵在科目二与科率的意义以及频率目三考试中需要补考的科目数为X,求X的分布列与数学期望,n(ad-bc)?[走进教材参考公式:X=(a+b)(c十dD(a+c)(b+d参考数据:Ca0.500.400.250.150.100.051.随机试验及其华x。0.4550.7801.3232.0722.7063.841(1)定义:对随利试验,简称试验20.(本小题满分12分)(2)特点:如图,在以P,A,B,C,D为顶点的五面体中,面ABCD为等腰梯形,AB∥CD,AB=2AD①试验可以在村2CD,面PAD⊥面PAB,PA⊥PB.②试验的所有可(1)求证:AD上PD;③每次试验总是0(2)若AD-PB=2,求直线PA与面PCD所成角的正弦值但事先不能确定D2.样本空间>考()S(1)随机试验E[典121.(本小题满分12分)点,常用w表示项式=1(a>b>0)的左、右焦点分别为F1,F2,若Q为椭圆上一点,满足QF十表示样本空间,」Q1,离心率为受限样本空间(1)求椭圆C的方程;事件的分类(1)随机事件((2)设P(1,0),过点P做两条直线l1,l2,直线(与椭圆C交于A,B两点,直线l2与椭圆C交于D,E两点,AB的中点为M,DE的中点为N,若直线4与直线4的斜率之积为3,且G(4,0),求我们将样证:M心与NG共线担2绵烟用大写字母A当A中某个样22.(本小题满分12分)(2)必然事件已知函数f(x)=lnx一ax..y小5Q作为自身的(1)讨论函数f(x)的单调性;验中总有一个(2)若g()=2,h(x)=f0)+g.称L为①若h(x)在定义域上单调递增,求实数a的取值范围;(3)不可能事件②若函数A(x)有两个极值点(x<,).证明:2h(x)+2na<2h(x)十a.空集O不包含生,我们称【2023高考冲刺试卷(二)·数学第4页(共4页)】
21.某同学用“五点法”面函数f(x)=4si(@x+)+B4>0,0>0,<号)在某一个周期内的函数图象列表并填入的部分数据如下表X1-3523X30x+002个22πAsin(@x+)+B050-50(1)求出f(x)的解析式,并写出上表中的x1:(2)将了()的图象向右移号个单位得到g)的图象,若总存在x0,2],使得3对如2受-5mg)2m+2成立,求实数m的取值范国
9在同一面直角坐标系中,二次函数y=m广:与反比例函数)-”的图象可能是二b020ABC中,∠AB=60点DE分别在边BCAB上且AD=ACBE=宽CADBE的值为0.5c二、填空题(本大题共4小题,每小题5分,满分20分)11.计算:(-2)°+1-2=1112计算:】公13.如图,AB是半圆0的直径,点C是AB上一点,BD分∠ABC,AB=6,BC=3,则图中阴影部分的面积是14.已知:抛物线y=x2-2ax与x轴交于点A,B(点B在x轴的正半轴)两点,且AB=4.(1)a的值为(2)若点P为抛物线上一点,PM小轴交直线)=3-4于点M,则PM的最小值为三、(本大题共2小题,每小题8分,满分16分)15.解方程:(2x+1(x-2)=-2.16,在如图所示的面直角坐标系中,△ABC各顶点坐标分别为A(-3,-1),B(-2,-3),C(-1,-2)(1)以点A为旋转中心,将△ABC绕点A逆时针旋转90°,作出旋转后得到的图形△AB,C1;(2)以点0为位似中心,在第一象限作出△ABC的位似△4,B,C,使△ABC与△A,B2C2的位似比为1:2.
经明,左边-中1-2=a-2”=8p1-2a+2a+1-24.1作用+】(网十1)方(师十1)n(a+1)港(程+1】(牌+行明左边一右边,即源等式或立。……………五.(本大题共2小题,每小是10分,满分20分】19.1)经明:直接(C.如谐1.CE是⊙0的切线,∠OCE=90:AC=AC,∠ABC=45'.∴.∠AOC=2∠ABC=9.∠AC+∠CE=I8',.AD∥EC。wnn+分(2)解:过点A作AF⊥EC生EC于点F,如西2∠AC=90',0M-(C.∠0MC=5.'∠BAC=75.∠hAMD=∠BAC-∠(MC=3oAD∥C.∠E-∠mD=30.∠E-90',∠AC=0°,0A-网边形(A℃是E方形,六AF-O八7分AD-6.2AF-TAD-3.在AMPE巾amE-能AE--10分团图220.解,在R△ACD中,¥∠ACD=90°,∠ADC=45,AC=CD=I47m2分在R△BDC中,an∠BDC-CD'BC=CD·tan33'=1H7X0.6595:55(m),6分AB=AC-BC=1H7-95.55=5l.4531.5(m).答:信号发射塔AB的高度约为5引.5m.10分六、(本题满分12分】21.(1)1036(2)280解,(1)本次构取的学生人数共有16÷40%=40(人),扇形烧计图中A所对应帛形圆心角的度数是30'×行=36.B等级的人数为40-(4十16+14)=6(人).
分耄3I报MATHEMATICS WEEKLY考答案人教版八年级·2022一2023学年·第43~50期主纳:张瑞资编:孟晓玲美编:花玉因为185出现了3次,出现的次数最多(3)山图象.知小军在30≤1≤45的时段内由对称性,知点(行.离学校的路程是:的一次函数.设函数解所以众数b是185.析式为s=ml+n(m0).设直线CM的解析式为y=ax+c将点C,M所以a=177.5,b=185.将点(30,4).(45,0)分别代人,得-a+c=0,(2)选乙.的坐标分别代人,得的mn6解得理由:乙的方差为日[2×(175-175)+2×15a+c=-1.n=12(180-175)+2×(170-175)2+1×(185-所以=-:+12(30≤1≤45解得175)+1×(165-175)]=37.5.令-+12=专,解得1=1空因为37.5<93.75,所以乙的成绩更稳定(3)①从均数和方差看,乙的成绩比甲的当时=音×9=3所以直线CM的函数解析式为y=-子x-成绩稳定:②从均数和中位数看,甲的成绩更好答:当小军和小虎迎面相遇时,他们离学校的路程是3千米由上-子子解相化品之23.(1)①3,522.(1)设租住三人间a间,双人间b间by=-2x+2②由①,得PC=CQ=5.根据题意,得23×200a+2×3006)=6300.所以点P(2,-2)所以PQ=PC+C灭=o.3a+2b=50.综上,点P的坐标为(经或(2,-2所以P?+PB=1+9=PQ故填PA?+PB=PO解得亿公=(2)(1)中结论成立,答:租住了三人间8间,双人间13间八年级下学期期末综合测试题(六)】理由:连接B(2)根据题意,得因为△ABC与△PCQ都是等腰直角三角形.-、1.D2.A3.A4.A5.B所以AC=BC,PC=QC,LACB=PCQ=90y=200x+300(50-x刃=-50x+7500(0≤6.C7.B8.A9.B10.A所以LACB+∠BCP=∠PCQ+LBCPx≤50,且x为整数).(3)因为-50<0,二、11.1212.7913.x=114.24即LACP=BCO.所以y随x的增大而减小15.1016.4或25所以△ACP≌△BCQ(SAS)所以PA=QB,∠CAP=LCBQ=45因为三人间共住x人,所以租住三人间李间,三、17.(1)原式=6万-号:(2)原式=-4+26。所以LABQ=∠ABC+∠CBQ=90°所以LPB0=90°.双人间0间:18.(1)点B(0,4)所以QB+PB=PQ,所以当:满足寺,502为整数,且寺最大,即(2)直线,的函数解析式为y=子x-2即PA2+PB=PO.19.(1)略.24.(1)在矩形ABCD中,AB∥DC,即AB∥DE.x=48时,住宿费用最低,(2)由已知,得S方=3'=9.所以LBAP=LE,LB=LBCE.此时y=-50×48+7500=5100<6300.因为P是BC的中点,所以BP=CP天6300元的住宿费不是最低:48人人因为SA=之AB·AF=之×3×1=号所以△ABP≌△ECP(AAS)住三人间,2人人住双人间的费用最低,最低所以Scw=Sw=多(2)①在矩形ABCD中,AD∥BC,费用为5100元所以S脑0m=9-2×号=6所以∠BPA=∠FAP.23.(1)因为四边形ABCD是正方形由折叠,得BPA=FPA所以LBAD=∠D=90°,AB=DA20.(1)过点A作AC1PQ于点C,则AC即为最短以ZAP=FPA所以FA=FP因为BFLAE,所以∠AMF=90°.距离。所以∠AFB+∠DAE=∠DEA+∠DAE=90°因为∠A0C=∠M0P,∠M0P=30°,所以∠AFB=∠DEA所以LAOC=30°.T∠AFB=∠DEA由折叠,得B'A=AB=6,PB=PB=4,B在△ABF和△DAE中,所以在Rt△AOC中,AC=号OA.LAB'P=∠ABF=90°LAB=DA.因为0A=1200米,所以AC=600米,即学校设FA=FP=x,则BF=x-4.所以△ABF≌△DAE(AAS).所以BF=AE.到公路PQ的最短距离是600米在Rt△AB'F中,由勾股定理,得(2)PQ=AE.证明略.(2)学校会受到广播噪音影响,FA2=BA2+BF.所以2=6+(x-4)(3)连接PE,因为四边形ABCD是正方形,理由:因为600<1000,解得x=号,即FA=男所以AB=AD=8.所以学校会受到广播噪音影响.(3)如图,设宜传车的广播噪音从点B处开始②由折叠,得AB=AB=6,BP=BP.因为PD=3,所以PA=AD-PD=8-3=5.因为POLAE,AN=NE,所以PA=PE=5.影响学校,到点B处结束影响,则影响学校的所以△PCB'的周长=CP+B'P+CB'=CB+因为D=90°,路段长为线段BB的长」CB'=8+CB在Rt△ACB中,AC+BC=AB由两点之间线段最短,可知当点B'恰好位于所以DE=√PE-PD=√S-3=4.因为AC=600米,AB=1000米,对角线AC上时,CB'+AB'最短,即CB最小.所以AE=√JAD+DE=√⑧+4=45连接AC,在Rt△ADC中,∠D=90°,所以BC=√AB-AC=800(米)所以PQ=AE=4N5,所以AC=√AD+DC=82+6=10.24,(1)设直线l,的函数解析式为y=kx+b.因为AB=AB',ACLBB根据题意,得化±6=0,解得=,2,所以BB'=2BC=1600(米)所以GB的最小值=AC-AB=10-6=4.因为宜讲车的速度是400米/分,所以学校受所以△PCB周长的最小值=8+CB=8+1b=2.1b=2.到影响的,总时长=1600÷400=4(分),4=12.所以直线l,的函数解析式为y=-2x+2B'Q③AB=2HG.(2)因为-2<0,所以y随x的增大而减小.理由:如图,由折叠,得∠1=2,AB=AB当x=-2时,y=-2x+2=6:BB'LAE.当x=4时,y=-2x+2=-6BM过点B'作BM∥DE,交AE于点M.所以当-2 九度测评叫2023年安徽中考第二次模拟考试数学(沪科版)试题解析与评分标准一、选择题(本大题共10小题,每小题4分,满分40分)1.-2023的相反数(B)1A.B.2023D.-202320232023【解析】:绝对值相等,正负号相反的两个数互为相反数.本题选B.2.下列计算不正确的是(C)A.a2.a2=a4B.(a2)3=a6C.(2a2)3=6a6D.a4÷(-a)2=a2【解析】:A.a2.a2=a4;B.(a2)3=a;C.(2a2)3=(2)3(a2)3=8a6≠6a;D.a4÷(-a)2=a4÷a2=a2∴A,B,D选项均正确;故本题选C.3553.魏晋南北朝时期,我国数学家祖冲之利用割圆术,求出圆周率π约为113,其与元的误差小于0.00000027.其中0.00000027用科学记数法可表示为(A)A.2.7×10-7B.0.27×106C.2.7×106D.2.7×107【解析】:绝对值较小的数,用科学记数法表示:a×10",其中1≤d<10,n指从左边起,第一个不为零的数前面零(包括小数点前面零)的个数,所以本题选A.4.如图,将一个正方体沿图示四条棱的中点切掉一部分,则该几何体的俯视图是(C)【解析】:自几何体的上方向下投射,在水投影面得到的视图称为俯视图看不到,且存在的线用虚线,所以本题选C5.下列分解因式正确的是(C)A.a2-ab+a=a(a-b)B.a'b-2ab+b=b(a2-2a+1)数学试题答案第1页(共13页) 0当∠PBA最大或最小时,PB与圆M相切,连接MP、BM,可知PM⊥PB,|BM=V(0-5)2+(2-5)}2=V34,MP=4,由勾股定理可得BP=VBM-MPP=3V2,CD选项正确,故选:ACD.【点睛】结论点睛:若直线1与半径为r的圆C相离,圆心C到直线1的距离为d,则圆C上一点P到直线l的距离的取值范围是[d-r,d+r].10.如图,由M到N的电路中有4个元件,分别标为元件1,元件2,元件3,元件4,电流能通过元件1,元件2的概率都是p,电流能通过元件3,元件4的概率都是0.9,电流能否通过各元件相互独立.已知元件1,元件2中至少有一个能通过电流的概率为0.96,则()元件1元件3元件2元件44A.卫=5B.元件1和元件2恰有个能通的概车为名C.元件3和元件4都通的概率是0.81D.电流能在M与W之间通过的概率为0.9504【答案】ACD【分析】根据独立事件的概率乘法公式以及互斥事件的概率的加法公式,可得答案。【详解】对于A,由题意,可得C2p(1-p)+p2=0.96,整理可得p2-2p+0.96=0,则(-1.2p-08)=0,则p=0.8=专,故A正确:25,故B错误对于B,C2p(1-p)=C×0.8×1-0.8)=0.32=8,对于C,0.9×0.9=0.81,故C正确:对于D,元件3,元件4中至少有一个能通过电流的概率为C2×0.9×(1-0.9)+C2×0.92=0.99,试卷第6页,共21页 12.4所以a-1=0.提示:所以a=1,即被遮住的一次项系数为1.7.原式=3(a2-4)=3a(a+2)(a-2).20.(1)山题意,得(x+4x+4y2)+(y2-4y+8.(4r-x+1j-3x)=-12x+2r-3x4)=0.所以(x+2y)2+(y-2)2=0.9.闪为m+5n=2,所以/e+2=0,y-2=0.所以2×32”=2"×2=2+=2”=4解得x=4,10.由解密规则.可得y=2.当a=2.6=4时,m=2+2×4+4×4=所以x=(-4)=16.(2)由题意,得(a-124+36)+(U2-86+40,n=(46-2m)÷4h=6-20=4-3×16)=0.所以(a-6)2+(b-4)2=0.2=3.11.f÷(2m=[2m)°-2×(2m'+4×(2)月÷所以任-8(-2a)=(32a-16a+16a)÷(-2a)=-16a'+解得亿车8a-8.因为a,b,c是△ABC的三边长,Hc为最长12.丙为m2+m2+10=6m-2n,边,所以6≤c<10.所以m2-6+9+n+2n+1=0,又因为c为偶数,即(m-3)2+(n+1)2=0.所以c的值为6或8.所以m-3=0,且n+1=0.五、21.(1)M=(3.x2-4x-20)-3x(x-3)=3x2-所以m=3,n=-1.4x-20-3x2+9x=5.x-20.所以m-n=4.P=(3x2-4x-20)+(x+2)2=3x2-4x-20+三、13.(1)原式=a-46x2+4x+4=4x2-16.(2)原式=-(a2-4b+4)=-a2+4ab-4b.(2)P=4x2-16=4(x2-4)=4(x+2)(x-2).14.(1)原式=a(6+a-2)=(a-)(3)对丁P=4x2-16,(2)原式=(x-7)因为4x2≥0,15.改小长方形①的长为x、宽为y所以整式P行最小值,口?x=0时,整式P由题意,可得(x+y)2-3xy=22,(3x+Y)(x+的最小值为-16.3y)-7y=96.22.(1)是.整理.可得x2+y-y=22,①(2)因为x+y与x2是P的个方差分解,x2+y2+y=32.②所以P=(x2+y)2-(x2)2=x+2xy+y-x=将②-①,得2y=10.2xy+y.解得y=5.(3)当k=-5时.N为“明礼崇德数”.故小长方形①④的面积为5.理山:囚为N=x2-y2+4x-6y+k=(x2+4x+16.原式=(x2-y2+xy+22-x2+2xy-y2)÷y=4)-(2+6+9)+k+5=(x+2)2-(y+3)2+3xy÷y=3x.k+5,1x=-1时,原式=3×(-1)=-3.所以当k+5=0时,V=(x+2)2-(y+3)2为17.因为a+b-8+(ab-12)=0,“明礼崇德数”,此时k=-5.所以a+b-8=0,b-12=0.故当=-5时,N为“明礼崇德数”所以a+b=8.ab=12.六、23.(1)因为正方形的面积可表示为(a+b+c)2,所以c8-a6=a+-2n且正方形的面积=a2++c2+2h+2e:+22-ab2c.所以(a+b+c)2=a2++c2+2ab+2be+-(a+6)-2b22ac.=号-2×12=8(2)H(1),可知2+b+c2=(a+b+c)2-2·(ab+bc+ac)=112-2×38=121-76=45.四、18.(1)A=x”+4x+4+x”-1-3=2x2+4x(2)因为x2=4.(3)因为长方形的面积=3a2+7ab+4b=所以x=±2,3a2+3ab+46+4ab=3a(a+b)+46(b+当x=2时,A=2×4+4×2=16:a)=(a+b)(3a+4b).hx=-2时,A=2×4+4×(-2)=0所以该长方形的长为(3a+46).综上,4的值为16或0.(4)因为长方形的向积=a+zab+yb2=(25a+19.(1)原式=x-x3+3x3-3x2+2x2-2x=x+6b)(18u+45b)=4502+1125ab+108b+2a3-x2-2x.270h2=450m2+1233ab+270b2,所以x=450.(2)设被遮住的一次项系数为a,y=270,z=1233.则(x2+ax+2)(x2-x)=x-x3+ax2-ax2+所以x+y+z+198=450+270+1233+1=2x2-2x=x+(a-1)x3+(2-a)x2-2x1954.因为答案中不含三次项,故填1954 理由如下:如图2,延长CE交AB丁H,E..GCD图2由旋转可得:CD=DE,BD=AD,,∠ADC=∠ADB=90°,.∠CDE=∠ADB',又:CDADDE=DB=1,∴.△ADB'∽△CDE,∴.∠DAB=∠DCE,∠DCE+∠DGC=90,∴.∠DAB'+∠AGH=90°,.∠AHC=90°,.CE⊥AB';(3)如图3,过点D作DH⊥AB于点H,B图3·△BED绕点D顺时针旋转30°,.∠BDB=30°,BD=BD=AD,.∠ADB=120°,∠DAB=∠AB'D=30°,DH⊥AB,.AD=2DH,AH=√3DH=BH 全国100所名校高三AB测试示范卷札记.f(x)在(6,十∞)上单调递增.②当a=0时,f(x)=x,显然f(x)在(6,十∞)上单调递增,③当00时,(x)=x十如,由对勾函数的性质知f(x)在(2√a,十)上单调递增,则2√a≤6,故0a≤9.∴.综上可知,实数a的取值范围是{aa≤≤9}.f(x)在(6,十∞)上单调递增的充要条件是“a≤≤9”【24G3AB(新教材老高考)·数学-必考-N】 - A.2W2C.32D.4W2答案】C【详解】由题意,在△4BC中,S=,asin4+esinC=4 asin Csin B,由正弦扇理,sin=sin B=sinCS=zaesin B+e=4acsinB6,BF,BH,FHa b c13如下图所示,在△BFH中,由余弦定理,FH=FB2+HB2-2FB·HB.cos∠FBH,又∠FBH=3n」Fl=FB+HB-2FB.HB cosB=2ta)+4ae sinB=2FH =32.二、选择题:本题共4小题,每小题5分,共20分.在每小题给出的选项中,有多项符合题目要求.全部选对的得5分,有选错的得0分,部分选对的得2分9.已知+F)展开式中的第三项的系数为45,则A.n=9B.展开式中所有系数和为1024C.二项式系数最大的项为中间项D.含x的项是第7项【答案】BCD10.2022年11月17日,工业和信息化部成功举办第十七届中国芯”集成电路产业大会.此次大会以“强芯固基以质为本”为主题,旨在培育壮大我国集成电路产业,夯实产业基础、营造良好产业生态某芯片研发单位在“A芯片”上研发费用占本单位总研发费用的百分比y如表所示.已知)=40%,于是分别用p=30%和p=40%得到了两条回归直线方程:y=bx+a,y=b,x+a,,对应的相关系数分别为5、5,百分比y对应的方差分别为S、S?,则下列结论正确的是立y-可年份20182019202020212022附:b=à=少-b航年份代码x1234520%p40%50%9A.s>s2B.1>3C.i>6,D.a>a,【答案】ABC11.设A(-2,0),圆B:(x-2)2+y2=4(B为圆心),P为圆B上任意一点,线段AP的中点为Q,过点Q作线段AP的垂线与直线BP相交于点R.当点P在圆B上运动时,点Q的轨迹为曲线C,点R的轨迹为曲线C2,则下列说法正确的有()A.曲线C的方程为x2+y2=1B.当点Q在圆B上时,点的横坐标为4C.曲线C,的方程为x2-上=1D.C与C,无公共点3【答案】ABC12.若正实数a,b满足a>b,且na.Inb>0,则下列不等式一定成立的是()2020级高三年级下学期第五次模拟考试数学试卷3/11 选择性必修四Unit1参考答案及部分解析参考答案1-5 ABCCA6-10 CACBA11-15 BBAAB16-20 CBCBA21-25 DBBCA26-30 BDBAD31-35 CADBC36-40 DGBCF41-45 BCABD46-50 ACDBA51-55 CDDAC56.to make57.effective58.as59.Similarly60,are61.satisfaction62.be given63.there64.whom65.aspects写作第一节One possible version:Good morning everyone!It is my great honor to be here and share with you my thoughts aboutmy dream and futureWe all have some sort of ambitions or dreams.My dream is to become a world-class chef,whonot only makes delicious and creative dishes,but also promotes Chinese culture and buildsbridges of cultural exchanges by cooking as food always casts light on people's way of life as wellas their cultural values.I hold to my belief that as long as I strive hard for my dream,a rosyfuture can be promised.Thank you!第二节 大一轮复学案数学考点二正弦、余弦定理的简单应用多元分析(2)若CD=2√2,E为线段AD上靠近D的三角度1判断三角形的形状等分点,求CE的长例1(2021新高考Ⅱ,18,12分)在△ABC中,角A,B,C所对的边分别为a,b,c,且满足b=a+1,c=a+2.(1)若2sinC=3sinA,求△ABC的面积;(2)是否存在正整数a,使得△ABC为钝角三角形?若存在,求a;若不存在,说明理由方法感悟多个三角形背景下解三角形问题的思路(1)把所提供的面图形拆分成若千个三角形,然后在各个三角形内利用正弦、余弦定理求解。(2)寻找各个三角形之间的联系,交叉使用公共条件,求出结果解题时,有时要用到面几何中的一些知识点,如相似三角形的边角关系、行四边形的性质,要把这些知识与正弦、余弦定理有机结合,才能顺利解决方法感悟问题!1.判断三角形形状的两种常用途径迁移应用角通过正弦定理、余弦定理化角为1.(2023河北衡水模拟)在△ABC中,已知边,利用代数恒等变换得出边与边边判断途径之间的关系,再进行判断sinA+sinC_b+e,且满足①a(sinA-sinB)=sin B通过正弦定理、余弦定理化边为(c-b)(sin C+sin B);2bcos A+acos B=角,利用三角恒等变换得出三角形csin C中的一个条件,试判断△ABC的形状,角内角之间的关系,再进行判断并写出推理过程,2.判断三角形形状时的注意点在判断三角形的形状时,一定要注意三角形的解是否唯一,并注意挖掘隐含条件.另外,在变形过程中,要注意角A,B,C的范围对三角函数值的影响,在等式变形时,一般两边不要约去公因式,应移项、提取公因式,以免漏解。角度2正弦、余弦定理在面几何中的应用例2(2022安徽宣城模拟)如图,在△ABC中,AB=√3,∠ABC=45°,∠ACB=60°,点D在边BC的延长线上(1)求△ABC的面积;.94· 大一轮复学案数学迁移应用2an+511数列{a,}是首项为1,公差为6的等差8.5解析a1=0,a+1=√3+aa所以16-8a.212数列,an=1+(n-1)×6=6n-5,,∴.a2-3a52a.+552·51a*14数列{a,的前n项和S,=1+6n-5)xm16-8a.4an2-5,43+32511-3x√3-2=-3,4=1)=3n2-2na-2考点二所以数列是首项为-2,公比为3-35bn+i=0,.数列{a}是以3为周期1+W3x√5dn-4例2解析(1)证明:由题设得5-的周期数列,且a,+a2+a,=0,则S24=a1+子的等比数列,2b1-2,a2=V3.2-2故bSb1Cn+19证明因为7。。气,所以6,24即b1-b.=2所以5,解得a。因此{b,}是等差数列≠1,cn≠0,21(2)由b1=55=2得b1=23两边同时取倒数可得1-1=上-1,整2-1+52"+4因此6,空2于是5号b1-n+3里可得-(-0,所以数列故bn=12+13,nEN..2又5=号,所以3,{侣}为递装数列n+1第二节等差数列及其前n项和10.解析(1)若a=-7,则a,=1+2n-gne1知识梳理因此a1=S-5=(n+2)(n+1a+b3N)同一个常数2a1+(n-1)dna,+又a,=S,=,所以a的通项公式为an(n-1)d3结合函数)=1+的单调性,可知2,n=1,1>a1>a2>a3>a4,a5>a6>a2>…>an>1(n∈课前自测1N').1.×V/VV(n(n+1),n≥2.所以数列{a,}中的最大项为a,a5=1+2.D3.A4.B例3解析(1)由已知得,4a2+1=3+a2,15.3或4解析令an=0,得n=4,所以S24a,a+1=3ata,解得a,=3,a=32X5-g2,最小项为a,a,=1+2x4-9取得最小值时,n=3或4.=0.易错提醒易忽视a=0的项而致错(2)证明:由已知得,a1-4a,-3an-116.2解析2S=3S2+6,.2(a1+a2+a3)111112=3(a1+a2)+6,{a,}为等差数列,6a(2)a.=1+=1+已知对+2(n-1)2-a=3a1+3a2+6,.3(a2-a1)=3d=6,解得d则2a2a.2302a12·=2.4an-1任意的neN·,a,≤a恒成立,结合函数考点一4an-114an-1例1(1)B2(3a,-1)-(4a.-1D)2a.-1=20-1解析(1)由题可知1f(n)=1+-。的单调性,可知5<2-<2-2a+2d=4,26-72,a1=6,9x8.d=18d=-1.9a1+又六1{a(1是以1为6,解得-102n-6,整理得(n-1)(n-6)>0,当n≥2时,S1=(n-1)2a1,所以a.=S。解得n<1或n>6,Sn1=n2a1-(n-1)2a1=(2n-1)a1,经检验,数别是以11又n为正整数,故n的最小值为7.当n=1时,也满足题意,a1+1为首项,迁移应用所以a.=(2n-1)a1,neN',子为公比的等比数列,a-11an+1=31.1011解析由a.+a1=n①,得a1+当n≥2时,a-a.1=(2n-1)a1-(2n-3)aa2=n+1②,②-①得a2-a,=1,所以a2,=2a,(常数),(”43”-(-1)a4,a6,…是首项为0,公差为1的等差数.{a}是等差数列.3”+(-1)m2a.+5列所以a=4+(g24-小x1=101考点三例4(1)10(2)0例2解析由已知得a1680由方2.3n2-2n解析数列{2m-1}的项为1,解析(1)由a1+2a,=15,得3a5=15,解程总得不动点分子153,5,7,9,11,13,…,数列{3n-2}的项为1,得a,=5,所以a2+a=2a,=10.4,7,10,13,…,(2)根据题意可得a1+ag=2a,=π,2a1+·456· 第十一章三角形11.3多边形及其内角和11.3.1多边形2考建议用时:20分钟教材改编题6.下列关于正多边形的说法错误的是()A.各个内角都相等◆基础B.各条边都相等知识点1多边形及其相关概念C.各个外角都相等1.下列图形属于多边形的是D.各条对角线都相等综合7.如图,把周长为36的正三角形ABC纸板,裁AB2.(教材P20图改编)下列面图形中,不属去三个小正三角形(阴影部分)得到正六边形DEFGHI,则正六边形的边长是多少?于凸多边形的是知识点2多边形的对角线考第7题图3.(教材P21第1题改编2考)一题多变3.1将四边形改为六边形8.一题多设问从正几边形的一个顶点出发从六边形的一个顶点出发,可作的对角线的条数为(可以作条对角线。A.2B.3C.4D.5(1)该多边形是正边形;3.2将已知与结论互换求多边形边数(2)将该多边形剪去一个角后,它可能是从一个多边形的顶点出发,可作9条对角边形;线,则该多边形是(3)若该正多边形的边长为5,求多边形的A.十边形B.十一边形周长C.十二边形D.十三边形(4)画出该正多边形的大致图形,并在图中4.(教材P28第4题改编)从一个n边形的同画出其全部的对角线,并直接写出对角线一顶点出发,分别连接和它不相邻的各顶条数点,若把这个n边形分成8个三角形,则n的值为知识点3正多边形27考5.下列图形一定是正多边形的是A.直角三角形B.等腰三角形C.圆D.正方形13 2023州新尚函数'()×测研考试的象的一个低点二、填空顺:本题共2小题,每小服6分,共12分00全国@⊙所名校高三AB测试示范卷·数学7.2红+1≤3”是“子<”的一条件(横线上填,充要,充分不心要必要不充分纸不第三套滚动内容+十一元二次函数、方程与不等式(B卷)充分也不必要),(40分钟100分)8已知二次函数y,若八-)=0,且2r<),则/0-奢情分析,讯每修门线三、解答顺:本顺共3小M,共52分,解答应写出文字说明、证明过程成演算步康,高考对接点一元二次画数、才程为不¥式是高者家者点0.(17分)学疑难点方但不等式的及用已知a>0,b>0,且a+b=2.溶动内容集合、儿分必要条件、全称量词内存在量训级看章课程氧课外脑解标典型情境题3、10下维复课件证明,(1)a+∥>≥21一、进择题:本题共6小题,每小题6分,共36分(2h+号>1.若集合A=(x1x-21<1),B=(x2-5.x+4>0,则下列结论正确的是A.A∩B=ABAUB-RC.ACBD.AC CB2.已知a,b,c∈R,若a>b,则下列不等式一定成立的是A.a+bb-ca&<8cD.(b-a)2>03.已知x>0,y>0,若x+y+3y=16,则xy的最大值为A.1B2C22D.44.若正数xy满足42+4xy+2y2=2,则2x+y的取值范围为o克B(12)C(w2.2)D.(0,2)5.已知a,b为正实数,且ab+2a+b=6,则A.ab的最大值为4-、2B2a+b的最小值为√2+2C.a+b的最小值为4、2-3D。中+6十2的最小值为号6.(多选题)若Vx∈(0,+∞),不等式ax+3x2≤abr+3b(b>0)恒成立,则A.a>0B.a'b=9C.a2+4b的最小值为12D.a2+ab+3a+b的最小值为6-2√3题序1256苔案·5·【24·G3AB(新高考)·数学(三)一必考一N】 Researchers collected waste samples (over a第period of three years.They walked about 12"I am concerned about products that are likely tokilometers each day,looking for waste as well as第二部secretly collect personal information about peoplewithout their awareness.While we have becomeother signs of elephants,including footprints andused to people using smartphones to take images in部broken trees.They tested the waste samples forDNA.public places,photographing or filming peopleDuring their counting efforts,the researchersthrough a camera located in sunglasses can morelooked for fresh waste.Sometimes,they would findeasily happen without being obvious.Chief Wearables Officer for EssilorLuxottica,elephant waste that was too old to be used asevidence.When they found a sample,they put it in aa global leader in the eyecare and eyewear industry读small glass bottle.They sent the bottles to a读Rocco Basilico said the goal was that peoplelaboratory in Libreville,Gabon's capital.recorded moments through their own eyes as theyThe samples had to be dealt with first tohappened,so they can be present rather thanremove organisms(有机体)that could affect results..searching for a photo.Stephanie Bourgeois was one of the writers of aFacebook said it would issue guidelines for the use第published study about the elephant count.She said第of the glasses,because "we need to educate peoplethe DNA helped the scientists make a guess at howin advance on how to use Ray-Ban Stories smartmany different elephants lived in the area that theglasses safely and responsibly,both for their own部samples came from.They learned that in Gabon,部protection and that of others around them"But Dr Belinda Barnet from Swinburnethere were about 95,000 forest elephants.Earlierguesses were much lower,at 50,000 to 60,000.University of Technology said Facebook's smartEven with the new information,theglasses represented“a Pandora'sbox(潘多拉的魔International Union for Conservation of Nature盒)of privacy issues'”.Its safeguards(安全条例)believes the population of forest elephants in阅读seemed designed to protect people using the glasses读Central Africa has greatly shrunk.It says thebut not the people in front of them."They don'tnumbers have been reduced by 86 percent over thelook like cameras and if someone walks up to youlast 30 years.holding their camera out,you'd be careful,but withthese you're not going to know about it."(C28.Why was the waste of elephants collected?(O32.What is Angelene Falk's concern about the第A.To study the organisms in it.第new smart glasses?B.To study the forest elephants'diet.A.They are hardly allowed to be used in部C.To learn of the population of forestpublic places.elephants.B.They may have the same function asD.To know about the elephants'healthconditions.分smartphones.C.They may invade people's privacy(D)29.What did the scientists probably do whenD.They can replace cameras one day.collecting elephant waste?(D)33.What did Facebook mainly focus on while读A.They tested the waste on site.designing the smart glasses?B.They put all waste in one bottle.读A.Their safety.B.Their popularityC.They stored every piece they found.C.Their affordability.D.They gave up the waste that was too old.D.Their convenience.(A34.What is Dr Belinda Barnet's attitude towards第(B)30.How did the scientists probably feel when第the smart glasses'safeguards?learning of the result of the research?A.Passive.B.Curious.C.GratefulD.Careless部分A.Angry.B.Surprised.C.Worried.D.Proud.部(B)35.What is the best title for the text?A)31.What does the underlined word“shrunk”inA.How can people use Facebook's smartglasses wisely?the last paragraph mean?B.Do Facebook's smart glasses invade圜A.Dropped.B.Spread.people's privacy?C.Moved.D.Grown读C.How can people protect their privacy inpublic places?D.Will smart glasses replace traditionalg原cameras in the future?D第二节第Facebook's new video-recording sunglasses,阅读下面短文,从短文后的选项中选出可以填入空白处created in partnership with Ray-Ban,promise to第的最佳选项。选项中有两项为多余选项。record photos and videos to be shared on socialIt makes the world go around.It causes increased heartbeat.It makespeople feel excited,energetic and warm.Sometimes it also teaches lessonsDmedia.But their design has been questioned by分and causes pain.36 That's right-we're talking about love!privacy experts,including the Office of the分37Most people feel love for members of their family,such as theAustralian Information Commissioner(OAIC),aslove between parents and children,brothers and sisters,couples or loversThey may feel this same feeling toward friends or even petsthere is little in their design that reminds othersA.Love comes in many forms.B.What actions make you feel loved?读that the glasses are equipped with two cameras and读C.Of course,words work just fine.too!people's privacy can be invaded(侵犯).D.Can you guess what we are talking about?E.The love between couples is quite different from that between friendsAustralian Information Commissioner andE That's because loveart of what humansneed inorder tolivPrivacy Commissioner Angelene Falk said,G.Thus,spending time wth oved make people live onger 选项D错误故选:BC.三、填空题13.1014.V615.(-0,0)U(1,+o∞)16.【答案】【解析】首先证明一个结论:在三棱锥S-ABC中,棱SA,SB,SC上取点A,B,C,则4s-S4-sBSGVs-ABCSASB·SC设SB与面SAC所成角为O,则489_g-4_321.1.4.sCsin 0.SB'sin ASC S4SBSCVs-ABCVB-SAC.54.SC.sin0.SB.sin ZASC M.SB..SC现业解答本题:设P5=x,PFx,p0,Vp-版cDx4X2S1PB34则V,-AEr=x·yV,-AB1=3x,Vo-ur=2223,av==23,ae=g+g=m+w=2g-6+刃,则x+y=3y,3y-110≤x≤10≤y≤1则;sys1,mx+功乱*号 【分析问题】由勾股定理,可以通过构造直角三角形的方法,来分别表示长度为V1+x2和V1+(1-x)2的线段,将代数求和转化为线段求和问题.【解决问题】D(1)如图,我们可以构造边长为1的正方形ABCD,P为BC边上的动点.设BP=x,则PC=1-x.则V1+x2+V1+(1-x)2=线段+线段(2)在(1)的条件下,已知0 22.(本题满分12分)已知集合A={2≤x≤5},B={xm+1≤x≤2m-1},且B≠0.21h-17,m+17m72(1)若命题“Vx∈B,xeA”是真命题,求m的取值范围;(2)若命题x∈A,x∈B”是真命题,求m的取值范围.“:U)BCAm+7-2ZLm232m寸52m-1m9)°共)蓝(2)/XeAX4B时一言只中其个四 ABCDE所成角的余孩值为吾.故选A号的国与侧西BC,B的交线,交线为的放国,5.连接AC、AD1,:AB∥D交线长为2xX号×=匹,D不亚确,故选ABC1D1且AB=C1D1,则四边244形ABC1D1为行四边形,7.命题①,由于两条行线中的一条直线与一个面垂.异面直线DC和BC1所成直,则另一条直线也与该面垂直,故①为真命题;命的角为∠ADC.AG=题②,m,n可能异面,故②为假命题;命题③,可能nCAD1=DC,则△ACD为正α,故③为假命题;命题④,由线面垂直、线面行的性三角形,即2ADC=号,A质以及面面垂直的判定知④为真命题;命题⑤,由m不正确;连接B1C,在正方形∥n,m⊥a,得n⊥a,又a∥B,∴.n⊥B,故⑤为真命题.综上,正确命题的序号为①④⑤.BB1C1C中,BC1⊥BC,8.将图1中的△AA1B和△A1BC放置于同一-个面AB⊥面BB1C1C,B1CCB内,如图2所示,则PA十PC≥AC.直三棱柱面BBCC,∴AB⊥B1CAB∩BC=B,则BC⊥ABC-A1B1C1中,BC=2AA1=2,AB=AC=√3,.在面ABC1D,.直线BC与Rt△A1AB中,∠ABA1=30°,A1B=2.同理,在面ABC1D1所成的角为Rt△A1AC中,A1C=2,∴∠ABC=60°,∴.在图2中,∠ABC=∠ABA1+∠A,BC=90°,.AC=AB2+∠CBC=牙,B正确;根据等体积转换可知Vo-AcD,BC=7,.PA十PC的最小值是√7.2号×1X1,则A-停,C正喷:三被柱AA,D-BB,G的外接球即为正方体ABCD-A1BCD,的外接球,则外接球的半径即为正方体ABCD-A1BCD体对角线的图1图2一年,即R=号,D正确故选BD9.在正方体ABCD-A1B1CD6.如图,延长BA,B1M交于D1中,连接BC1,FD1,AD1,点O,连接OC,AM∥如图,对角面ABC1D1为矩BB,.△OAM∽形,点E、F分别是棱BC,△OBB1,又M为AA,的OCC1的中点,则EF∥BC∥中点,.OM=MB1,AO=ADL,而EF=号AD,即BA=AC,.BC LOC,.面AEF截正方体所得截面为梯形AEFD1,显然过点OC=√5,A正确;连接B1C交BC1于点N,,四边形C1与面AEFD1行的面交面BCC1B1、面B1BCC1为矩形,∴.N是B1C的中点,连接MN,则ADDA,分别于BC1,MN,因此MN∥BC,连MC1,MN为△BOC的中位线,.MN∥OC,又MNC面BMNC1、面AEFD1与面ACC1A1分别交于面BMC,OC丈面BMC,∴.直线OC∥面BMC,MC,AF,因此MC1∥AF,而AM∥FC,即四边形B正确;取B1C1的中点P。,连接A1P,则A1P。⊥B1C1,又由CC1⊥面A1B,C,A1P。C面A1BC,AMCF为行四边形,于是AM=FC=合,即点MA1Po⊥CC1,又B1C1,CCC面B1BCC1,B1C∩为AA的中点,同里N为AD中点,MN-,:动CC1=C1,可得A1P。⊥面B1BCC1,又BCC面B1BCC,故A1P⊥BC1,过点P。作PPo⊥BC,垂足点P始终满足PC1∥面AEF,于是PCC面为P,连接A1P,A1P。⊥BC,PP。⊥BC,AP∩BMNC,又P在侧面ADD1A1上,∴.点P的轨迹是PP。=Po,A1Po,PP。C面A1PP,.BC⊥面线段MN,轨迹长为号:以点D为原点建立空间直商A1PP。,又A1PC面A1PP,.A1P⊥BC1,C不正确;A1P。⊥面B1BCC1,.D中所求交线即为坐标系,则M1,0,),N号,01D,A1,00,F0,面BCCB内以P为圆心,年径为√)-(停)1,,则=(-20,含.-(00,含.a-40 题报第⑥期第15章数据的收集与表示自我评估参考答案答案速览(3)通过观察统计图,得顾客满意度高,洗衣液的销售量-、1.C2.A3.A4.C5.B6.B7.D8.D9.C就会上升,顾客满意度低,洗衣液的销售量就会降低,10.D21.解:(1)2000解析:700÷35%=2000(人),二、11.0.412.313.514.252°15.1016.①②④三、解答题见“答案详解”(2)400解析:2000×20%=400(人).(3)在扇形统计图中,各部答案详解分扇形圆心角的度数分别为:道路交17.解:(1)108÷0.54=200(人).环境保护通20%道路交通:360×20%=72°;35%其他答:调查的总人数为200人房屋建设:360°×15%=54°;房屋建5%设15%(2)m=200×0.15=30,n=18÷200=0.09.环境保护:360°×35%=126°;绿化25%18.解:(1)40100解析:调查总人数为80÷20%=400(人),绿化:360°×25%=90°;所以a=400×10%=40,b=400-80-40-120-60=100.其他:360°×5%=18°.(2)E所在扇形的百分比为60÷400×100%=15%.用扇形统计图表示如图所示D所在扇形的圆心角度数为120÷400×360°=108°.22.解:(1)抽取总人数为7÷35%=20(人),其中偏胖人数19.解:(1)由题意,得六个班的获奖总人数为15×6=90(人),为20-2-7-3=8(人).所以三班获奖人数为90-14-16-17-15-15=13(人).补全条形统计图略补全折线统计图略,(2)9解析:小张的体重为27×1.70=78.03(kg)(2)由题意,得二班的参赛人数为16:32%=50(人)若要使自己的BMI值达到正常,则小张的体重需小于24×因为6个班每班参赛人数相同,所以七年级参赛总人数为1.702=69.36(kg).6×50=300(人).所以他的体重至少需要减掉78.03-69.36≈9(kg).20.解:(1)120四102二(3)答案不唯一,如坚持锻炼身体;合理饮食,营养均衡(2)甲乙 四解容惠术题共6小愿,共0分.解答应写出文字说明、证明过程欧演算步骤。州*涧分16分)发】h.7 b382.已知{0.}为等差数列,么}是比为正数的等比数列,4三6=24=26-1,6=24+2(①)求数列{a,}和6,}的通项公式:(2(2)设数列{o,}满足c,=记{cn}的前n项和为S,求S223a log2b了八奇0<0o+o)ie=门e当。)小翰@明18.(本小题满分12分)如图,已知行六面体ABCD-ABC,D中,所有棱长均为2,底面ABCD是正方形,21.(本侧面ADD4是矩形,点P为DC的中点,且PD=PC.兴本已知(I)求证:DD,⊥面ABCD:且双曲线(2)求面CPB与面DPB夹角的余弦值.(1)求(2)若有近线上,过线斜率的范19,(本小题满分12分)9:30火42为大+1己知函数f(x)=+bx+1a,be)在x=1处取得极值0()求a,b:0)g2b(0Qatb-12)着过点(仙,m)存在三条直线与曲线y=∫)相切,求实数m的取值范围.正由题了f:2以3-3数学试题内第4页,共6页数学试题 獬得a=5,b=1.(3分)所以E的方程为-=1.e。....e(4分)》,x3-y=1,(Ⅱ)由消去y整理,得2x2-12x+15=0,y=x-2,设A(x1,出1-2),B(为2,x-2),则出1+名=6,x1名=215不妨设出>名,计算可得飞,=3+5名,2%=36所以1AB1=√1+121x1-2I=25.......................(6分)由条件,可知直线AD的方程为y=-(x-x,)+x1-2,与双曲线方程号-=1联立,消去y整理,得2x-12(-1)x+12-24x+15=0,由根与系数的关系得xD=(x1+xD)-x1=5x1-6,同理xc=5x2-6.…(8分)》所以1AD1+1BC1=2(x-x,)+2(xc-x2)=2(4x,-6)+万(4x2-6)=42(x,+x2)-122=122.…(10分)所以四边形ABCD的面积为AD1十BC×AB1=2,2×25.=12,6.…(12分)2220.命题意图本题考查数列的通项公式与求和,以及数列不等式的证明.解析(I)当n=1时,S1=a1=4a1-6,从而a1=2,…(1分)当n=2时,S1+S2=2a1+a2=4a2-8,从而a2=4.…(2分)》当n≥2时,由S,+S2+…+Sn=4an-2n-4,得S,+S2+…+S,-1=4a-1-2(n-1)-4,两式相减得S。=4a。-4a-1-2,从而S+1=4a+1-4a。-2,…(3分)所以an+1=4a+1-8an+4an-1,整理得3(a+1-2an)=2(an-2an-1).…(4分)又a2-2a1=0,从而an+1-2an=0,即an+1=2a。,…(5分)所以{an}是首项为2,公比为2的等比数列,其通项公式为a分=2.(7分)(Ⅱ)由(I)知bn=log2an=log22”=nn…(8分)当n=1时,不等式显然成立;……(9分)当2时<产2+)(10分)所以安+安*+安+空+…+<1+(兮》+兮》++(女】1=1+2(兮2n+)<1+号=3综上可知,原不等式成立.(12分)21.命题意图本题考查二项分布的分布列和期望,以及概率的计算,解析(I)由题意可知X~B(3,号),(1分)6 Tt5数M:Well,I'd like to offer you the position.Do you stillM,Let me see that.Wow!The Grand Canyon look likewant it?such a cool place.W:Thank you,but I've accepted another job already.W:Arizona is a pretty cool state though it's actually hot.M:Oh,that's OK.It's the desert.5下,自,Tet6p分的白个同动M:Well,what other fun places are there in Arizona?M:What industry are you in?W:A lot of people go to Sedona to seeitred rock TheyW:In advertising.I'm an account manager at MCE.Whatare amazing.about you?s清程点g0指米M:People go there to look at rocks?M:I work in the IT industry.I'm a market manager forW:And to explore.You can hike or take a jeep tour.NK network.M:That sounds fun.W:That's great.I have several clients that areW:Or you can take a balloon ride and see the rocks fromabove,which is what I like most.technology companies.Let me know if you needText 9advertising services in the future.M:Will do.I believe we will have many opportunities forM:Hi there,welcome to Styleshop.Can I help you withanything today?cooperation.W:Let's get some more appetizers.The main course 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sings very well.第二部分1-5 DCBAC 6-10 BCDAD11-15 DABCA16-20 BDADC第三部分21-25 TFTFT26-30 BBADC31-35 ACBBC 36-40 CBBBD41-45 EDGAB第四部分第一节46.service47.them48.second49.worst50.reporter第二节51.all kinds of52.As long as53.is like54.bring out55.look different第三节Dear Fiona.4/5 A.Her eagerness to learn more about her students.
B.Her students'unwillingness to face their emotions.
C.A desire from students to share their dreams.
D.The necessity of exhibiting her students'achievements.
31.What can be the best title for the text?
A.A class for sharing mental problems
B.An effective tool for improving teaching
C.Magic post-it notes from stressful students
D.A teacher's method for addressing students'
mental
health



