【文档说明】吉林省吉林市2022-2023学年高三下学期2月第二次调研测试 数学 答案.pdf,共(8)页,447.187 KB,由管理员店铺上传
转载请保留链接:https://www.doc5u.com/view-277c72c1cfbd7216451e812642fb67a8.html
以下为本文档部分文字说明:
高三数学试题答案第1页(共8页)吉林市普通中学2022—2023学年度高中毕业年级第二次调研考试数学试题参考答案一、单项选择题:本大题共8小题,每小题5分,共40分.12345678DCADDDBC二、多项选择题:本
大题共4小题,共20分.全部选对的得5分,部分选对的得2分,有选错的得0分.三、填空题:本大题共4个小题,每小题5分,共20分.13.,4114.715.2697;1a16.)2,0[1
1题解析:解析:23288)(xxxxxf.令0)(xf,则2x;令0)(xf,则2x且0x;)(xf的增区间为:),(2,减区间为:),),(,(200.对于A选项:6)2(
f且)(xg有三个零点,6a,即A选项正确;对于B选项:当0x时,016)82()82()()(22xxxxxxfxf,)()(xfxf.)()(31xfxf,)()()(331xfxfxf.)(xf
在),(0上单调递减,31xx,即031xx,即B选项错误;对于C选项:令2)0()(2)(2)(,,xxfxfxg.0)4(12)(4)(2)(2)(2222xx
xxfxfxg,)(xg在2)0(,上递减,即0)0()(gxg.202x,0)()(4)(2222xfxfxg,)()(422xfxf.)()(32xfxf,)()(432xf
xf.又)(xf在),(2上单调递增,324xx,432xx即,C选项正确;对于D选项:)()(21xfxf,2221218282xxxx,即082212121))((xxxxx
x.21xx,212116xxxx.)()()()(21221212212124164xxxxxxxxxx令021txxt,,则331022212224232216416tttttxx)()()(,故D选项正确
.[另解:由)()()(321xfxfxf,可得0163131xxxx,故B错;323216xxxx,由基本不等式可得C对.]15题解析:(1)由斐波那契数nF除以4的余数按原顺序构成的数列}{na,是以6为最小正周期的数列,所以2697133782023
321aaaa9101112ADBDACDABC高三数学试题答案第2页(共8页)(2)由斐波那契数nF的递推关系可知:2n时12nnnFFF,且121FF,aF2024所以1)()()(22024202320243423202221a
FFFFFFFFFFF.(也可直接由性质12321nnaaaaa得出结论)15题说明:本题源自人教A版选择性必修第二册P10—P11页阅读与思考部分内容.斐波那契数列}{na满足:11a,12a
,21n-nnaaa2)(*n,Nn,该数列通项公式为:])251()251[(51nnna(用无理数表示有理数的典型代表)常考性质:(1)12232221nnnaaaaaa,即112nnnkkaaa.(2)n-naaaaa212531
,即nnkkaa2112.(3)1122642nnaaaaa,即11212nnkkaa.(4)12321nnaaaaa,即121nnkkaa.(5)ka4
为3的倍数.四、解答题17.【解析】(Ⅰ)设在男生、女生中分别抽取m名和n名,则15001009001500900nm,解得:40,60nm.·····························
································································2分记抽取的总样本的平均数为,根据按比例分配分层随机抽样总样本平均数与各层样本平均数的关系,可得:)(142.15100402.1310060
cm所以,抽取的总样本的平均数为cm14.·······································································5分(Ⅱ)男生样本的平均数为2
.13x,样本方差为36.1321s;女生样本的平均数为2.15y,样本方差为561722.s;由(Ⅰ)知,总样本的平均数为14.记总样本的样本方差为2s,则16]})142.15(56.17[40])142.13
(36.13[60{1001222s························9分所以,估计高三年级全体学生的坐位体前屈成绩的方差为16.·········································10分(注:本次考试给出了分层随
机抽样的方差公式,但是此公式需要记忆,请老师在教学中强调并指导学生完成公式的推导.)18.【解析】(Ⅰ)(法一)利用余弦定理因为6coscosBcCb,由余弦定理,得622222222aa
cbcacabcbab··································································4分(法二)利用正弦定理因为6coscosBcCb,由正弦定理,得
6)(2BcosCsinCcosBsinR6)(2CBsinR62AsinR即6a················································································
············4分(Ⅱ)选择①:2646sinsinCcsinBbsinAa所以Bsinb26,Csinc26.················································
····················5分所以)(4sinsin218sinsin218bcsinA21SABCBBCB高三数学试题答案第3页(共8页)BcosBBBBBsBB2992sin9sin18co
ssin18sin22co22sin2182)(94229)(Bsin···················································································9分因为ABC是锐角
三角形所以2020CB又BC43,所以243020BB,所以24B.···············10分所以43424B,所以142sin22)(B.·····················
···················11分所以2942299)(Bsin.所以929S18ABC··············································
····································12分(注:利用余弦定理,解出929bc,仅得出ABCS的最大值,给9分)选择②因为10cb,则bc10因为ABC是锐角三角形,所以
02co02co02co222222222abcbasCacbcasBbcacbsA,即010b360b103603610222222222222222
)()()(bcbabbcabbacb所以534516b········································································7分因为bbabcbasCco31652222,所以
bbbCcosCsin23)8)(2(41所以bbbbabsinCSABC3)8)(2(4321161042bb,)(534516b···················································10分由二
次函数16102xxy的性质可得,当5x时,函数取最大值9;当516x时,25144y.所以12548ABCS··································································
··························12分法二:ABC中,610BCABAC,所以点A的轨迹为以B,C为焦点,10为长轴长的椭圆的一部分.以BC中点为坐标原点,BC所在直线为x轴建立平面直角坐标系.可得A点所在的椭圆为:116252
2yx,如图································································6分不妨设A在x轴上方,坐标为),(00yxAbcacbsAco2222bcbccb23
622)(1322bc264bcbc02571253214322)(cb,高三数学试题答案第4页(共8页)当且仅当cb时,即A点在短轴端点2A时,取得最小值,此时角A最大是锐角,此时40y,12210yaSABC···········
··················································································8分当AB与x轴垂直时,即A点在图中1A时,角B为直角,此时5160y,548210yaSABC当AC与x轴垂直时,即A点
在图中3A时,角C为直角,此时5160y,548210yaSABC······························································
······························································10分综上,A位于除去端点的弧31AA上时,满足ABC是锐角三角形.021yaSABC,)(45160y····················
························································11分所以12548ABCS同理可得A在x轴下方时,12548ABCS,综上,12548ABCS········
·················································································12分19.【解析】法一(几何法)(Ⅰ)因为四边形ABCD为菱形,所以BDAC,因为FCFA
,且O为AC中点,所以OFAC,·····················································2分OOFBD,BDEFOF,BD平面所以AC平面BDEF······
·····················································································5分(Ⅱ)因为四边形BDEF为矩形,连
接OE,12BF,BD,且O为BD中点,所以22EF,EOFO,222EFFOEO,所以FOEO.由(1)可知OACEO,ACFO,所以FO平面AEC又EA平面AEC,所以EAFO.过O作AEOG,连
接GF,又OOFOG,所以EA平面OFGGF平面OFG,所以GFEA,则OGF为二面角CAEF的平面角·················································
···················8分在EOARt中,OAOEEAOG,56EAOAOEOG在FOGRt中,5425622OFOGFG·················································10分则
46FGOGOGFcos所以二面角CAEF的余弦值为46.··································································12分法二(向量法)(Ⅰ)问同上(Ⅱ
)由(Ⅰ)可知:AC平面BDEF,ED平面BDEF,所以EDAC.因为四边形BDEF为矩形,所以BDED,且OACBD,所以ED平面ABCD因为60DAB,取AB中点M,连DM,则CDDM.以D为坐标原点,DM,DC,DE
所在直线分别为x,y,z轴,建立空间直角坐标系·······································································································
······················6分高三数学试题答案第5页(共8页))(000,,D,)(013,,A,)(100,,E,)(020,,C,)(113,,F)(113,,AE,)(120,,AF,)(033,,AC设平面AEF的一个法向量为)(1111z,y,xn
则0011AFnAEn得0203zyzyx取3y,则36x,z得)(6331,,n···································
·······························································8分设平面AEF的一个法向量)(2222z,y,xn则0022ACnAEn得03303yxzyx取3x,则21z,y得)
(2132,,n···································································································10分设
二面角CAEF为,由图可知二面角为锐角则464133693122121nnnncos所以二面角CAEF的余弦值为46··············································
·······················12分法三由(Ⅰ)可知:AC平面BDEF,ED平面BDEF,所以EDAC.因为四边形BDEF为矩形,所以BDED,且OACBD,所以ED平面ABCD取EF中点
N,以O为坐标原点,OA,OB,ON所在直线分别为x,y,z轴建立空间直角坐标系,如图所示·······························································································
···6分)(000,,O,)(003,,A,)(110,,E,)(003,,C,)110(,,F)(113,,AE,)(113,,AF,)(0032,,AC设平面AEF的一个法向量)(1111z,y,xn则0011AFnAEn得
0303zyxzyx取3x,则03y,z得)(3031,,n·········································································
························8分设平面AEC法向量为)(2222z,y,xn则0022ACnAEn得03203xzyx取1z,则01x,y得)(110
2,,n·································································································10分设二面角C
AEF为,由图可知二面角为锐角高三数学试题答案第6页(共8页)则4629332121nnnncos所以二面角CAEF的余弦值为46·····································································12
分20.【解析】(Ⅰ)31a311S又数列nSn为以2为公差的等差数列nSn12n即nnSn22································································
···················3分2n时,14)1()1(22221nnnnnSSannn1n时,31a符合上式数列}{na的通项公式为14nan.·····································
····································6分(Ⅱ))341141(2)1()34)(14()14()1()2()1(1nnnnnaaabnnn
nnnn···························8分9244]38131[21)]381181()151111()11171()7131([212nnnnnTn数列}{nb的前n2项和92442nnTn
·····························································12分(注:写成6161612nTn,本次考试不扣分,但教学中请强调结果最简化)21.【解析】解:(Ⅰ)由已知可得:2212)(22xyx,整理化简可得:
3322yx,即1322yx所以动点M的轨迹方程为:1322yx·····················································4分(Ⅱ)方案一:由OQOP可设直线OP的方程为kxy,直线OQ的方程为x
ky1·······················5分由3322yxkxy,可得22223333kkykx2,所以2222233(1k)kyxOP同理可得122233
(1k)kOQ,又由02|OP|且02|OQ|可得3312k······················7分法一:所以32)3(1133112222kkkOPOQ2·····························
····································8分所以)11)((23222222OPOQOQOPOQOP所以6)12(223)(223222222OPOQOQOPOQOP········
································10分当且仅当3OQOP时等号成立所以22OQOP的最小值为6···········································································
12分法二:所以1))(3(3)6(113)3(13)3(12222222222kkkkkkkOQOP······································8分令4)341(2tkt,高三数学试题答案第7页(共8页)则1)211
16(61616364))(3(46222222tttttttOQOP·························10分所以当211t时,即1k时,22OQOP有最小值为6.···········
······························12分法三:310332)3103(23103)12(61))(3(3)6(1242242424222222kk
kkkkkkkkkkOQOP103332222kk······································································
······8分设)331(1)(xxxxf222111)(xxxxf令310)(xxf令1310)(xxf)(xf在)131(,递减,在)31(,递增············································
·······························10分)31()3()()1(ffxff即310)(2xf即10)1(3622kk所以622OQOP即22OQOP的最小值为6···········································
········12分法四:因为0130322k,k所以6)2133()6(11))(3(3)6(113)3(13)3(1222222222222222kkkkkkkkkkOQOP····10分当且仅当13322kk时,即1k时,
22OQOP有最小值为6.··························12分方案二:当直线m的斜率不存在时,设直线m的方程为0xx则)(),(0000y,xQy,xP2323023)33(20202020202020y,
xxxxyxOQOP6)(2202022yxOQOP··················································································5分当直线m的斜率存在时,设直线m的方程为tkx
y设其与动点M的轨迹相交于)(11y,xP,)(22y,xQ所以tkxyyx3322联立得:0)-0(332)(32222kt-ktx-xk·····························6分其中
0-32k,03)12(3))(4(34Δ222222kttktk①由韦达定理可得:22132kktxx,2213kt-xx23········································
···········7分由OQOP可知:02121yyxxOQOP所以03332)()(1))((222221212121kkttxxktxxktkxtkxxx
OQOP2所以33222kt②,·························································································8分由①②可得222222212222)(33)12()(1)1kktkxxk(PQ
OQOP所以)96166(1969)106(242242422kkkkkkkOQOP······································10分当0
k时,66166(12222)k9kOQOP当0k时,622OQOP高三数学试题答案第8页(共8页)所以22OQOP的最小值为6···········································································
····12分22.【解析】解:(Ⅰ)函数)(xf的定义域是)0(,,0)11(112)(22xxxxf,)(xf在)0(,上单调递减.·································································
··················4分(Ⅱ)12)(xxlnxg,定义域是)0(,,则xxxxg212)(,令0)(x'g,则20x;令0)(x'g,则2x.)(xg在2)0(,上单调递增,在)(2,上单调递减.················
·····································5分0(1)g,.lng,lng0324(4)0232(3)(3,4),0x使0)(0xg,即1200xxln.
当01xx时,0)(xg;当10x或0xx时,0)(xg···································7分0))((2nmxxxg当01xx时,02nmxx;当10
x或0xx时,02nmxx.1和0x是方程02nmxx的两个不等实数根.042nm,由韦达定理mx01,.nx01,xn,xm001.nm1·············································
·························8分法一nm111211121112112nnenlnnnenlnnnenlnnnm又由1200xxln1200xex又0xn21nen原式1)(112
nfnnnln(其中(3,4)0xn).········································10分由(Ⅰ)知)(xf在区间(3,4)上单调递减且..lnf,.lnf050411241(4)35035321(3)01])([nf.
即011122nnenlnm.···············································································12分法二由1nmnm1
11211121112112nnenlnnnenlnnnenlnnnm又由1200xxln1200xex又0xn21nen,12nnln原式nnnn1111
···················································································10分)31,41(1(3,4)0nxn01n即011122nnenlnm.··
·············································································12分