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遂宁市高中2024届第四学期期末教学水平监测数学(理科)试题参考答案及评分意见一、选择题(5×12=60分)题号123456789101112答案ADBBCCDBCADB二、填空题(每小题5分,共20分)13.4014.51k−且2
k−15.316.3三、解答题17.【详解】(1)设椭圆的长轴长为()20aa,焦距为()20cc由条件可得210,24ac==.所以5,2ac==.................................................................
.2分所以22225421bac=−=−=........................................................................................3分当椭圆的焦点在x轴上时,标准方程为2212521xy+=;.........
......................................4分当椭圆的焦点在y轴上时,标准方程为2212521yx+=...................................................5分(2)当抛物线的焦点在x轴上时,可设所求
抛物线的标准方程为22(0)ypxp=−将点P的坐标代入抛物线的标准方程得1644pp==...........................................6分此时,所求抛物线的标准方程为28yx=−;...............................
.................................7分当抛物线的焦点在y轴上时,可设所求抛物线的标准方程为22(0)xmym=−,将点P的坐标代入抛物线的标准方程得48m=,解得12m=,.......
.........................8分此时,所求抛物线的标准方程为2xy=−.....................................................................9分综上所述
,所求抛物线的标准方程为28yx=−或2xy=−........................................10分18.【详解】(1)因为函数32()()fxaxbxx=+R的图象过点(1,2)P−,所以2ab−+=..1分又因为2()32fxaxbx=+,且()
fx点P处的切线恰好与直线30xy−=垂直,所以(1)323fab−=−=−,........................................................................................3分由2323abab−
+=−=−解得13ab==,所以32()3()fxxxx=+R.......................................5分(2)由(1)知2()36=3(2)fxxxxx=++,令()0fx,即3
(2)0xx+,解得<2x−或0x,令()0fx,即3(2)0xx+,解得20x−,..................................................7分所以()fx在(,2)−−单调递增,(2,0)−单调递减,(0,+)单调递增
,..............9分根据函数()fx在区间[,1]mm+上单调递增,则有12m+−或0m............................................................................................
......11分解得3m−或0m...............................................................................................
.......12分19.【详解】【详解】(1)由题知123451962303023904823,32055xy++++++++====()()()55211(2)(124)(1)(90)0702162732,10iiiiixxyyxx==−−=−−+−−+++=−=()()()(
)122117327320.988741.21054944niiinniiiixxyyrxxyy===−−===−−...............................5分因为0.75r,所以认为相关变量,xy有较强的相关性.
.............................................6分.(2)由(1)得()()()121732ˆˆˆ73.2,32073.23100.410niiiniixxyybaybxxx==−−====−=−=−....10分.回归方
程为ˆ73.2100.4,yx=+当6x=时ˆ539.6y=,即2023年该公司投入研发人数约540人...............................12分.20.【详解】(1)列联表如下:........................
........3分..2230(12549)0.40822.0721614219K−=,...............................................
..............5分所以没有85%的把握认为学生对“数学建模”选修课的兴趣度与性别有关;........6分(2)由题意可知X的取值可能为0,1,2,3,则3539C5(0)C42PX===,124539CC10(1)C2
1PX===,214539CC5(2)C14PX===,3439C1(3)C21PX===,故X的分布列为X0123P5421021514121510514()0123422114213EX=+++=.......................
...............................................12分21.【详解】(1)双曲线的焦点坐标为)0,1(),0,1(−,所以椭圆的焦点坐标为)0,1(),0,1(−1分
.感兴趣不感兴趣合计男生12416女生9514合计21930又椭圆中,21FPF面积最大值3221==bcS,故3=b.................................3分所以椭圆C的方程为:134
22=+yx;............................................................................4分(2)设),(yxR,由于直线过原点,则),(yxS−−,)0,(xE..
...........................................5分所以直线SE的斜率kkxykRSSE21212===.............................
....................................7分(3)由题设,可设直线l为(3)ykx=−且0k,联立椭圆方程,整理得:2222(34)2436120kxkxk+−+−=,则422(3457648)(31)0kkk=
+−−,所以21442040k=−,即151555k−且0k,所以222434MNkxxk+=+,2212(31)34MNkxxk−=+,.....................................................8
分若存在(,0)Tt使MTONTA=恒成立,则||||NMMNyyxtxt=−−,.......................9分由椭圆对称性,不妨令,MN在x轴上方且NMxx,显然MNxtx
,所以NMMNyytxxt=−−,即()0()()NMNNMMNMMNMNytyyxyxyytxtxtxtx+−−+==−−−−,.............10分所以()MNNMMNtyyxyxy+=+,即(3)(3)23()66NMMNM
NMNMNMNxxxxxxxxtxxxx−+−−+==+−+−11分综上,222222222224(31)7272247234342424182434436kkkkkkkkkkt−−−++−−−===−+,所以,存在4(,0)3T使MTONTA=恒
成立........................................................12分22.【详解】(1)求导aexfx−=)('................................................................
............1分①当0a时,)(xf在R上递增...........................................................................3分②当0a时,)(xf在)ln,(a
−上递减,在),(ln+a上递增.....................5分(2)①等价于()()()()elnelne0xxxhxxaxxxaxx=−+=−有两个零点,令extx=,则()1e0xtx=+,在0x时恒成立,所以extx=在0x时
单调递增,所以()()elnexxhxxax=−有两个零点,等价于()lngttat=−有两个零点..........6分因为()1atagttt−=−=,所以当0a时,()0gt,()gt单调递增,不可能有两个零点;当0a时,令()0gt,得ta,()gt单调递增,令()0
gt,得0ta,()gt单调递减,所以()minl(n)ggataaa==−,若()0ga,得0ea,此时()0gt恒成立,没有零点;若()0ga=,得ea=,此时()gt有一个零点;若()0
ga,得ea,因为()110g=,()ee0ga=−,2ee0()aaga=−,所以()gt在()1,e,()e,ea上各存在一个零点,符合题意,综上,a的取值范围为(e,)+......
........................................................8分(方法不唯一)②要证)(2lnln2121xxxx+−+即证:2lnln2211+++xxxx,即证()1212lneln2(
)exxxx+,由(2)中①知111extx=,222extx=,所以只需证12lnln2tt+.....................9分因为11lnatt=,22lnatt=,所以()2121lnlnatttt−=−,()2121lnlnatttt+=+,所以221121212122
121lnlnln(lnln)1tttttttttttttt+++=−=−−,只需证2211221ln21tttttt+−..10分设120tt,令21tmt=,则1m,所以只需证1ln21mmm−+即证4ln201mm+−+,令4()ln21hm
mm=+−+,1m,则22214(1)()0(1)(1)mmhmmmm−=−=++,()()10hmh=,即当1m时,4ln2011m+−+成立.................................
..........................11分所以12lnln2tt+,即)(2lnln2121xxxx+−+.................12分(方法不一)获得更多资源请扫码加入享学资源网微信公众号www.xiangxue100.com