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第1页共4页2023——2024学年度高2024届半期考试数学参考答案(理科)一、选择题题号123456789101112选项BDCDCAABACAB二、填空题13.135°14.2815.219116.57三.解答题:17(Ⅰ)bB
−=1cos4,根据正弦定理得BB−=2sin1cos4,即=−sin21cosBB)(,代入BB+=22sincos1,即−=−=−+2241cos1cos1cos1cosBBBB)()()(,由于B−1cos0,即−
=+41cos1cosBB)(,解得B=cos35.…………5分(Ⅱ)根据正弦定理得ACac+=+=sinsin221,即ac+=2,由(Ⅰ)知b=85.由余弦定理得=+−=+−=−22222cos1654165bacacBacacac)(,解得ac=920.…………
10分又因为B=cos35,所以B=sin45.ABCSacB==12sin950.…………12分18.解:(1)由条件知⊥⊥=FDDCFDADADDCD,,,面平⊥⊥FDABCDFDCM,.………………2分ADAMMBBCaDAMCBM=====
=,,90,===+=⊥DMMCaCDaDMCMCDCMDM22,,.222……4分面平⊥=⊥CMDMFDDMDCMFDM,,.………………5分(2)以D为原点,DADCDF、、为、、xyz轴的非负方向建立空间直角坐标系.(MaaFa,,0),(0,0,),,2,0)=0,2,),
CaFCaa(,0(−,,0)DMaa=(,()(=0,2,=0,2,1FNFCaaDNDFFNaa=−=+−,))(………6分设平面DMN的法向量为(,,,nxyz=1)由1=210nDMaxaynDNayaz=+=
+−=01)(得,取=z2,则=−=−yx1,1.(1,1,2.n=−−1)………………8分由(1)知,平面FDM的法向量为(,,0)MCaa=−………………9分由题意()()1CMcos,=CM2212nCMnn
==)(−+−aa33211221,…………10分解得2=.1……………12分19.解析:(Ⅰ)两人得分之和不大于35分,即两人得分均为17分,或两人中1人17分,1人18分,NDFCEABMzyx{#{QQABLYKQogCAAAAAAAgCEwUACkMQkA
CCAAoOAFAAsAABQRNABAA=}#}{#{QQABLYKQogCAAAAAAAgCEwUACkMQkACCAAoOAFAAsAABQRNABAA=}#}第3页共4页21.解:(1),,·······1分
∵的定义域为.①即时,在上递减,在上递增,,无极大值.·······2分②即时,在和上递增,在上递减,’,.·······3分③即时,在上递增,没有极值.·······4分④即时,在和上递增,在上递减,∴,.·······5分综上可知:时,,无极大值;时,,;时,没有极值;时,,.··6分(2)
设,,设,则,,,∴在上递增,∴的值域为,·······8分①当时,,为上的增函数,∴,适合条件.·······9分②当时,∵,∴不适合条件.·······10分③当时,对于,,令,,存在,使得时,,∴在上单调递减,∴,即在时,,∴不适合条件.综上,的取值范围为.······
·12分=−−+Fxxxaxax2ln2)(=+−−xFxxaxa222)()(=+−xxax21)()(Fx)(+0,)(≤−a20≥a0Fx)(0,1)(Fx)(+1,)(小极=−Fxa1)(Fx)(−a201−a20F
x)(−a20,+1,)(−a2,1大极=−FxFa2)(=−−−aaaa42ln2小极==−FxFa11)()(−=a21=−a2Fx)(+0,)(Fx)(
−a21−a2Fx)(0,1)(−+a2,Fx)(−a21,大极==−FxFa11)()(小极=−FxFa2)(=−−−aaaa42ln2≥a0小极=−Fxa1)(Fx)(
−a20大极=−FxFa2)(=−−−aaaa42ln2小极==−FxFa11)()(=−a2Fx)(−a2大极==−FxFa11)()(小极=−FxFa2)(=−−−
aaaa42ln2+=−xhxaxx2cossin)(≥x0)(()+=−+xhxax2cos12cos2)(=txcos−t1,1()+=+ttt2122)(()+=−+−tttt22214)()()(()≥+=−−tt2021
3)(t)(−1,1t)(−31,1≥a31≥hx0)(hx)(+0,≥=hxh00)()(≤a0=−ha22201a301x20−hxaxx3sin
)(=−Txaxx3sin)(=−Txax3cos)(x20,xx0,0)(Tx0)(Tx)(x0,0)(=TxT000)()(xx0,0)(hx0)(a+3,1{#{QQABLYKQogCAAAAAAAgC
EwUACkMQkACCAAoOAFAAsAABQRNABAA=}#}第4页共4页22.解:(1)消去参数t,得曲线C1的直角坐标方程为−=−yx2211)(,即−+=xy230.把==yxsincos代入=6sin2,曲线C2的直角坐标方程为+−
=xyy6022.…5分(2)圆心到直线AB的距离为()−==−+d1+25|0233|32圆上动点P到弦AB的距离的最大值为=+dr5+33解法1:弦长=−=−=rd55AB2233122222∴PA
B的面积S的最大值为=55225ABd=+31+5.1112318)(………10分解法2:设圆C2上动点+P(3cos,33sin),P到直线C1的距离===+−+−+−−−−d5555333
cos2(33sin)+36sin3cos335sin()3化C1的参数方程为=+=+ytxt521512代入+−=xyy6022得,+−=tt57022则+=−=−tttt5,721212则()=−=+−=−−=−ABtttttt5544(7)212
12121222∴PAB的面积S的最大值为=55225ABd=+31+5.1112318)(23.解:(1)+++=−++=−−−−xxfxfxxxxxx22,1()(4)|1||3|4,3122,3-------
-3分当−x3时,−−x228,解得−x5;当x1时,+x228,解得x3综上,原不等式的解集为(,5][3,)−−+------------------5分(2)因为ab||1,
||1,所以=−=−fababab()|1|1,=−=−aaafababb||()|||1|||令=−=−−−amfabafabbab()||()1||,-------------7分若ba,则=−−−=−+mabbaab1||(
1)(1),因为ab||1,||1,所以m0,所以afabafb()||();-------------9分若ba,则=−−−=+−mabbaab1||(1)(1),因为ab||1,||1,所以m0,所以afabafb
()||()综上所述,afabafb()||()------------10分{#{QQABLYKQogCAAAAAAAgCEwUACkMQkACCAAoOAFAAsAABQRNABAA=}#}获得更多资源请扫码加入享学资源网微信公众号w
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