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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22294313231
29194acacb++=,整理得2221143bccaa=++........................................9分故2222211343acacccaa+-=++,解得3
4ac=.............................................................................................12分19.(1)证明:连接AO......
.......................................................................................1分O为BC中点,ABC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PAOBOPABVV
1133AOBPABSPOSd155AOBPABSPOdS115315hd点M到平面PAB的距离为1515…………………………………………………………12分20.(1)解:max()1()1()0,()1(
)0,()1()(1)xxxfxexfxexfxfxxfxfxfxfe=-¢=¢<>¢><\==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()(,1maxaeaaF
xFax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02l
n)(eeeet又eaea101…………………………………………………………………………11分综上所述,a的取值范围是)1,0(e………………………………………………………………12分2
1.(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,1222122843
41243kmxxkmxxkì-+=ïï+í-ï×=ï+î,··················································································6分()()222222644434121
9248144kmkmkmD=-+-=-+,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()()()12121212121212122242224kxxkxx
mxxmkxmkxmkkxxxxxx++++++++=+=+++++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222192481441441440kmkD=-+=+>,符合题意.所以FPQ△的周长为48a=.························································
···············12分22.解:(1)由22cos62得22cos226.22222222222(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:0122m
m,1,22121mmmm,……………………………………………………8分6424)(2122121mmmmmmAB.……………………………………10分23.解:(1)化简得:1
2)(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,18a18
a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