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高三文科数学参考答案第1页共4页2023年高考桂林、崇左市联合调研考试文科数学参考答案1~12:CBBDABDCAADA13.-214.2.815.14416.42317.解:(1)由题中表格可得2×2列联表如下:……………2分由题意得:K2=;···········
·············································5分所以没有95%的把握认为“阅读爱好者”与性别有关.·················································6分(2)根据检测得分不低于80分的人称为“阅读达人”,
则这100名学生中的男生“阅读达人”中,按分层抽样的方式抽取,90,80内抽取3人:设为a,b,c,100,90内抽取2人:设为A,B,则基本事件:abc,abA,abB,acA,acB,aAB,bcA,bcB,bAB,cAB,共10种;…………
…8分至少有1人得分在100,90内的事件:abA,abB,acA,acB,aAB,bcA,bcB,bAB,cAB,共9种;10分所以这三人中至少有1人得分在100,90内的概率为109.…………………………12分18.解:(1)据已知及正弦
定理得()332bacacba--=+,....................1分整理得22223bacac=+-.......................................3分又
据余弦定理2222cosbacacB=+-得1cos3B=...........................................................................
........5分(2)2ADDC=因为所以1233BDBABC=+........................................6分223231BCBABD+=故,所以2
229431323129194acacb++=,整理得2221143bccaa=++........................................9分故2222211343aca
cccaa+-=++,解得34ac=.........................................................................................
....12分19.(1)证明:连接AO.............................................................................................1分O为BC中点,A
BC为等边三角形AOBC.............................................................................................2分阅读爱好者非阅读爱好者合
计男生451055女生301545合计7525100高三文科数学参考答案第2页共4页点P在底面ABC上的投影为点OPO面ABC.................................................................
...............................................3分POBC..........................................................................................
...................................4分由BCAO,BCPO,AOPOO,AO面APO,PO面APO得BC面APO...................................................................
.............................................5分AM面APOBCAM……………………………………………………………………………6分(2)设点M到平面PAB的距离为h,点O到面PAB的距离为d12PMMO,13hdBO为PB在
底面ABC上的投影PBO为PB与面ABC所成角,3PBO2PBRtAOP中,226APAOPO∵BA=BP=2∴B到PA的距离为21026222=-....................
.........................................................9分152PABS又32AOBS..................................................................
..................................................................10分由PAOBOPABVV1133AOBPABSPOSd155AOBPABSPOdS
115315hd点M到平面PAB的距离为1515…………………………………………………………12分20.(1)解:max()1()1()0,()1()0,()1()(1)xxxfxexfxexfxfxxfxf
xfxfe=-¢=¢<>¢><\==由题知:当时,单调递增;当时,单调递减;··························································4分高三文科数学参考答案第3页共4页(2)设1ln1)()(
)(axxexxgxfxFaxaxaxaxxeexaxaxeaxxF))(1(11)('………………………………………………………6分当0a时,0)('xF函数)(xF在),0(上单调递增,不合题意…………………………………………
……………7分当0a时,axxFaxxF10)(,100)(''所以函数)(xF在)10(a,上单调递增,在),1(a上单调递减所以x趋近0时,t趋近;x趋近时,t趋近21ln1)1()(,1maxaeaaFxFax时当方程1)()(xgxf有
两个不同的实根所以021ln1aea…………………………………………………………………………9分设2ln)(xexxt,易知函数)(xt在),(0上单调递增02ln)(eeeet又eaea101……………………………………………………………………
……11分综上所述,a的取值范围是)1,0(e………………………………………………………………12分21.(1)解:依题意可得2112243baab解得2,3ab所以椭圆E的方程为22143xy………………
…………4分(2)设直线()()1122:,,,,lykxmPxyQxy=+,················································5分由()22222,43841203412ykxmkxkmxmxyì=+ïÞ+++-=í+=ïî得,12221228
4341243kmxxkmxxkì-+=ïï+í-ï×=ï+î,··············································································
····6分()()2222226444341219248144kmkmkmD=-+-=-+,又11212112,222ykxmkxmkkxxx++===+++,来源:高三答案公众号高三文科数学参考答案第4页共4页故()()()12121212121212122242224kxxkxxm
xxmkxmkxmkkxxxxxx++++++++=+=+++++2222228241681612412161612kmkkmkmkmmmkmk---++=--++223644mkmkmk-=-+,····························
·····················································8分由0321=++kkkk,得0321=++)(kkk,得22320mkmk-+=,故()()202mkmkmk--=Þ=或mk=,·····················
································9分①当2mk=时,直线():22lykxkkx=+=+,过定点()2,0A-,与已知不符,舍去;········································
··································································10分②当mk=时,直线():1lykxkkx=+=+,过定点()1,0-,即直线l过左焦点,此时222192481441441
440kmkD=-+=+>,符合题意.所以FPQ△的周长为48a=.·······································································12分22.解:(1)由22cos62得22cos226.22
222222222(cossin)2()622636xyxyxyxy.所以曲线C的直角坐标方程为16222yx.……………………………………5分(2)设直线l的参数方程为mymx221221(m为参数),将l的参数方程代入
曲线C的普通方程,整理得:0122mm,1,22121mmmm,……………………………………………………8分6424)(2122121mmmmmmAB.……………………………
………10分23.解:(1)化简得:12)(axaxxf.当3a时,2)5()3(53)(xxxxxf,当53x时等号成立,所以)(xf的最小值为2;…………………………………………5分(2)由基本不等式:8)3212()212(2123
mmmmmmmm,当且仅当mm212,即4m时,等号成立.又因为1)12()(12)(aaxaxaxaxxf,当且仅当210xaxa时,等号成立.…………………………………………8分所以,18a18a
或18a9a或7a…………………………………………………………………………10分注:第17—23题提供的解法供阅卷时评分参考,考生其它解法可相应给分。来源:高三答案公众号