【文档说明】2023届山东省青岛市高三第三次适应性检测 数学答案.pdf,共(6)页,324.303 KB,由小赞的店铺上传
转载请保留链接:https://www.doc5u.com/view-e1c61419ac3d30e15ff5ae424d8f5e45.html
以下为本文档部分文字说明:
数学参考答案第1页(共5页)数学参考答案及评分标2023年高三年级第三次适应性检测准一、单项选择题:本题共8小题,每小题5分,共40分。1--8:CBADBCAD二、多项选择题:本题共4小题,每小题5分,共20分。9.BD10.
AC11.BCD12.ABD三、填空题:本题共4个小题,每小题5分,共20分。13.22143yx;14.3π4;15.28;16.1.四、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)解:(1)因为CcaB
ctan)2(sin2,所以CCcaBccossin)2(sin2··················1分所以CCACBCsin)sinsin2(cossinsin2,因为)π,0(C,0sinC,所以CACBsinsin2cos
sin2···························2分因为πCBA,所以CCBCBCCBCBsinsincos2cossin2sin)sin(2cossin2,所以CCBsinsi
ncos2,···········································································4分所以21cosB,又因为)π,0(B,所以3πB··
··············································5分(2)设xa,则xc3,由条件知)(21BCBABD·····································6分所以13413)cos2(41)(41||22222
xBaccaBCBABD························7分所以2x···································································································8分
所以22227cos2xBaccab,72b··················································9分所以周长728724xcbal·······························
·····················10分18.(12分)解:(1)取11CB的中点1O,连结11OA,因为ABAC,ABCCBA111为三棱台,4211BAAB,所以2π,21111111CABCABA,所以1111CBOA,211OA·············
········2分因为平面11BCCB平面ABC,平面//ABC平面111CBA,所以平面11BCCB平面111CBA,平面11BBCC平面111CBA11CB,所以11OA平面11BCCB······
·········································································3分由条件知梯形11BBCC的面积231)2422(21S
·································4分数学参考答案第2页(共5页)所以四棱锥111BBCCA的体积222331V·····························
············5分(2)取BC的中点O,连结AO,因为ACAB,所以AOBC,因为等腰梯形11BCCB中,OO,1分别为上下底面BCCB,11的中点所以1OOBC,因为平面11BCCB平面ABC,平面11BBCC平面ABCBC,所以1OO平面
ABC,以O为原点,分别以1,,OAOBOO所在直线为x轴,y轴,z轴建系如图,············6分则(22,0,0),(0,22,0),(0,22,0),ABC)1,2,0(1B,令1BBmBE)10(m,则),222
,0(mmE···········································7分设平面ACE的法向量为(,,)nxyz,因为(22,22,0)CA,),224,0(mmCE,则22220n
CAxy,0)224(mzymCEn,令mx,可得)224,,(mmmn··················································
········8分因为1OO平面ABC,所以)1,0,0(1OO为平面ABC的一个法向量···················9分记二面角EACB的平面角为,1027)224(2224cos
22mmm·······10分即0262mm,解得21m或32m(舍)···········································11分所以存在点E为BB1的中点,使得二面角EACB的余弦值为1027··········
······12分19.(12分)解:(1)因为nnnnaS3)1(1,所以nnnaS9122,nnnaS931212·········4分两式相减得,2212293nnnnaaa,所以2122293nnnnbaa,·············6分(2)
因为123,,aaa成等差数列,所以3122aaa,又因为321aa,9321aaa,所以0,3,6321aaa···························8分由nnnnaS3)1(1
可得,12113)1(nnnnaS,(1)n两式相减得,1121(1)(1)23nnnnnnaaa···········································9分当
22nk,2k且Nk时,22223kka,此时2122212221232333kkkkkkSa,2k································10分所以,2116,19,2nnnSn··············
··························································12分1OABC1A1B1COExyz数学参考答案第3页(共5页)20.(12分)解:(1)由题知:||4||PAPB,即32
4||||PAPB·······························2分所以曲线C是以)0,3(),0,3(BA为焦点,长轴长42a的椭圆························3分所以曲线C的方程为1422yx··········
···························································4分(2)设),(00yxQ,因为点),(00yxQ在椭圆C上,所以142020yx······················5分因为直
线txl:与圆Q相切于点M,所以||||0txQM··································6分2020)3(||yxQB····································
···········································7分假设存在,则||||)3(||02020txmQMmyxQB,即2022020)()3(txmyx,即2
202202200202332tmtxmxmyxx,因为142020yx,所以412020xy,所以04)322()43(2202202tmxtmxm恒成立·················
····················9分所以0432m,03222tm,0422tm············································10分解得334t,23m,所以存在23m及定直线334:xl
,满足条件············································12分21.(12分)解:(1)由题知:X的可能取值为1,0,1;················································
······1分321(1)(1)(1)4312PX;32325(0)(1)(1)434312PX;321(1)432PX··································································
················4分所以X的分布列为:X101P11251212所以1515()1011212212EX······································
··················6分(2)假设答题n轮,记nP表示“没有出现连续三轮每轮得1分”的概率,数学参考答案第4页(共5页)由题知:341234171131,1,1(),13()28216PPPP···········
····················7分经分析知:nP第n轮第1n轮第2n轮112nP没有得1分214nP得1分没有得1分318nP得1分得1分没有得1分所以123111(4)248nnnnPPPPn··································
·························9分解得111,,248abc··············································································10分
因为123111248nnnnPPPP,112111248nnnnPPPP,所以112111248nnnnnPPPPP12312111111()224848nnnnnPPPPP
31016nP所以1(4)nnPPn,且1234PPPP,可得12345PPPPP所以答题轮数越多(轮数不少于3),出现“连续三轮每轮得1分”的概率越大·······12分22.(12分)解:(1
)由题得:sin()exxcfx,cossin()exxxcfx·······························2分因为(0)10fc,得1c····················
···················································3分(2)因为sin1()1xbxfxa,所以sin10xabx······························
·······4分令()sin1xFxabx,()lncosxFxaabx,①若01a,则π(π)10Fa,不合题意··················································5分②若1a,1°当0b时,则()1sin0xFx
abx,适合········································6分2°当0lnba时,则()lncoslnln0xxFxaabxaabab,数学参考答案第5页(共5页)所以,()F
x在[0,π]单调递增,()(0)0FxF,适合····························7分3°当lnba,令()()gxFx,则2()(ln)sin0xgxaabx,所以()Fx在[0,π]上单
调递增,π(0)ln0,(π)ln0FabFaab,所以存在0(0,π)x使得0()0Fx,且()Fx在0(0,)x上单调递减,所以,当0(0,)xx时,()(0)0FxF;不合题意综上,lnba且1a·························
························································9分所以eelnabaa,令()eln(1)haaaa···············
····························10分则ee()1ahaaa,令()0ha,解得ea,当1ea时,()0ha,()ha在(1,e)上单调递减;当ea时,()0ha,()ha在
(e,)上单调递增;所以()(e)elnee0hah,所以eab···················································12分获得更多资源请扫码加入享学资源网微信公众号www.xiangxue100.com