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1参考答案1.【答案】C【解答】解:集合2{|4}{|04}Axxxxx,4{|340}{|}3Bxxxx,44{|4}(,4]33ABxx.故选:C.2.【答案】A【解答】解:由已知可得复数34(34)(12)11211212(12)(12)555iii
iziiii,所以复数z的实部为115,故A正确,复数z的共轭复数11255iz,虚部为25,其在复平面内对应的点112(,)55在第一象限,故B错误,C错误,22112||()()55
5z,故D错误,故选:A.3.【答案】D【解答】解:数列{}na是等差数列,数列{}nb是等比数列,且7943aa,26108bbb,313879423aaaaa,可得38132aaa
,368b,则62b,可得481413bb,381348213aaabb.故选:D.4.【答案】C【解答】解:函数sin21cosxyx,可知函数是奇函数,排除选项B,当3x时,32()31312f,排除A,x时
,()0f,排除D.故选:C.5.【答案】A【解答】解:由题意,可知:5log21a,110.5122221log0.25log5log425bloglog.0.20.51c,b最大,a、c都小于1.521l
og25alog,10.25551110.5()222c.而522log5log422,521152log.ac,acb.故选:A.6.【答案】D【解答】解:过E作//EFBC,交AB于F,设A到BC的距离为h,则12ABESEFh,
12ADCSCDh,由已知得12EFCDBD,{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}2故E为AD的中点,11211()()22323BEBABDBABCBABC
,ACBCBA,故11()()23BEACBABCBCBA
2222211111113332362362BABCBABC34.故选:D.7.【解答】解:由题意得111sin120sin60sin60222acac,即acac,得111ac,得4(4)(a
cac1144)525459cacaacacac,当且仅当4caac,即2ca时,取等号,故选:B.8.【答案】B【解答】解:作出函数()fx的图象如图所示,当0y时,()fxy只有一个根,当01y时,()fxy
有二个根,当12y时,()fxy有三个根,当2y时,()fxy有二个根,令()tfx,1()()32Ftftt的零点即为1()32ftt的根,作出两函数()yft与132yt可知两函数有两交点1t,2t,且101t,212t,所以函数1()[()]3()2Fxf
fxfx的零点个数是5个.故选:B.二.多选题(共4小题)9.【答案】AB【解答】解:对于A,220aaaa,1a或0a,1a是2aa的充分不必要条件,故A正确,对于B,0m,2x,20x,函数2
22222mmyxxmxx,当且仅当22mxx,即2xm时,等号成立,226m,解得4m,故B正确,对于C,当2a,1b时,则11ab,故C错误,对于D,当0b
时,满足//ab,//bc,但//ac不一定成立,故D错误,故选:AB.{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}310.【答案】BCD【解答】解:对
于选项2212:()3333AAEADDEADDCADACADADAC,故选项A不正确;对于选项B:易证明D
EFBFA∽,所以23DFDEBFAB,所以2235DFFBDB,故选项B正确;对于选项:2CAEBD,即2()()23ADABADAB
,所以2212233ADABADAB,所以1214233ABAD,解得1ABAD,cosAB,11212
||||ABADADABAD,因为AB,[0AD,],所以AB,3AD,故选项C正确.对于选项332:()()()555DFBFCDBFDD
CABADBDAB32()[()]55ABADADABAB332()()555ABADABAD,2296325
25ABABADAD93627425252525,故选项D正确.故选:BCD.11.【答案】AB【解答】解:由题设可得:14(1)43nann,(143)(21)2nnnSnn,21nSn
n,数列nSn的前10项和为10(119)13191002,故选项A正确;又若1a,3a,ma成等比数列,则231maaa,即2943m,解得21m,故选项B正确;111111()(43)(41)4434
1nnaannnn,111111111111()(1)415594341441niiiaannn,由111625niiiaa可得:6n,故选项C错误;又210mnaaaa,由等差数列的性质知
:12mn,m,*nN,1161116116125()()(17)(21617)12121212nmnmmnmnmn,当且仅当125485mn时取““,等号取不到,即1162512mn,故
选项D错误,故选:AB.{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}412.【答案】BCD【解答】解:2()lnxfxx,故()fx在(0,1)递
增,(1,)递减,其图像如下:易得若()2fxm有两个不同解,则021m,则102m,故A错误,当0k时,ykx与()yfx显然有且仅有1个交点,当0k时,则()yfx与ykx相切时,有且仅有1个交点,设切点为0(x,0)y,
切线方程为0002001()lnxlnxyxxxx,将原点代入:则100200020011()2lnxlnxxlnxxexx,2ek,故0k或2ek,则B正确;1xxe恒成立,()fx在(1,)上单调递减,111()()xxxxlnxxlne
fxfexee,故C正确;31218134221221122212222222lnlnlnelnlnelneeee,即比较(22)f与f(e)大小,又因为22e,()fx在(1,)递减,故(22)()ffe,D正确,故
选:BCD.三.填空题(共4小题)13.【答案】35.【解答】解:终边过点(1,2)P,2215cos512,2253sin(2)cos22cos12()1255.故答案为:35.14.【答案
】255.【解答】解:向量(1,2)m,(2,)n,若mn,则220mn,1,2(0,5)mn,2mn与m的夹角余弦值为(2)25|2|||5mnmmnm,故答案为:25
5.{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}515.【答案】212.【解答】解:()sin()fxAx,由图像知1A,142T,284,由五点作图法可知
,104,4,()sin()44fxx,f(1)0,f(2)22,f(3)1,f(4)22,f(5)0,f(6)22,f(7)1,f(8)22,f(1)f(2)f(3)f(8
)0,又222025286,f(1)f(2)f(3)(2022)2520ff(1)f(2)f(3)f(6)212,故答案为:212.16.【答案】3248nn
.【解答】解:12(1)(2)nnnnnnaEFECaEB,12(1)(2)nnnnnnECaEFaEB,又B,nF,C三点共线,12(1)(2)1n
naa,132(3)nnaa,又134a,{3}na是以首项为4,公比为2的等比数列,113422nnna,123nna,又nnBCBF
,()nnnnnnECEBEFEB,(1)nnnnnnECEFEB,又12(1)(2)nnnnnnECaEFaEB
,12(1)12nnnnaa,又123nna,122(123)24nnn,38(12)424812nnnTnn.故答案为:3248nn.四.解答题(共6小题)17.【解答】解:(
1)2coscoscosbBaCcA,由正弦定理sinsinsinabcABC,得2sincossincossincosBBACCA,即2sincossincossincosBBACCA
,即2sincossin()sinBBACB.0B,sin0B.2cos1B,即2cos2B,{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=
}#}6又0B,4B.(2)ACD中,5AD,7AC,3DC,2222225371cos22532ADDCACADCADDC.0ADC,23ADC.在ABD中,5AD,4B,3ADBADC,由正
弦定理sinsinADABBADB,得52322AB,562AB.18.【答案】(1)5{|12xxk,}kZ.(2)17.【解答】解:(1)因为3(2cos,)2ax,(sin(),1)3bx,()fxab,23133313()2cossi
n()2cos(sincos)sincos3cossin2cos2sin(2)322222223fxxxxxxxxxxxxsin(2)13x当时()fx取最大值1此时2232
xk,kZ,即512xk,kZ时,()fx取最大值1,所以当()fx取最大值时对应的x的取值集合为5{|12xxk,}kZ.(2)因为052[,]123x,所以02[32x,]
,又004()sin(2)53fxx,所以203cos(2)1(2)335xsinx,0445tan(2)3335x,所以00004tan(2)11133tan(2)tan[(2)]4123471tan(2
)1()33xxxx.19.【答案】(1)证明见解答;(2)1212nnnT.【解答】解:(1)证明:nS为{}na的前n项和,又13nnaSn,1(1)3nnaSn,(2)n,11nnnaaa,
112(1)nnaa,(2)n,又13a,2125aa,2112(1)aa,112(1)nnaa,*()nN,又112a,{1}na是以2为首项,2为公比的等比数列;{#{QQABRQ4
QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}7(2)由(1)可得21nna,又13nnaSn,11322nnnSann,12nnnb,23112222nnnT,34121
12122222nnnnnT,2312111122222nnnnT2211(1)1242122212nnnnn,1212nnnT.20.【
答案】(1)1(4,7)4.(2)332.【解答】解:(1)因为2223()2sinabcbcA,故22223(2cos)2sinabababCbcA,整理得到:23cos2sinabCbcA,即3cossinaCcA,故3sincossi
nsinACCA,而A为三角形内角,故sin0A,所以3cossinCC,故tan3C,而C为锐角三角形内角,故3C,23AB,可得22sincosAB222sin()cos3BB2231(cossin)cos22BBB222313cossincossincos4
42BBBBB22713cossincossin442BBBB331cos2sin244BB31sin(2)23B,因为三角形为锐角三角形,故022032BB
,故62B,故242333B,故33sin(2)232B,故2217sincos44AB,可得22sincosAB的取值范围为1(4,7)4.(2)由题设可得2BDDA
,故2()CDCBCACD,整理得到:1233CDCBCA,故222144999CDCBCACBCA,即22144
149992abab,整理得到:223642426ababababab,{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#
}8当且仅当23a,3b时等号成立,故()6maxab,故三角形面积的最大值为13336222.21.【答案】(1)nan,12nnb;(2)(1,5).【解答】解:(1)22nnSan①,当1n时,2111212Saa
,解得11a,21121nnSan②,②①得221121nnnaaa,所以221(1)nnaa,因为11a,{}na是递增数列,所以1na,所以11nnaa,即11nnaa,所以数列{}na是
首项为1,公差为1的等差数列,所以1(1)1nann,因为111ba,424428ba,2*21,nnnbbbnN,所以数列{}nb是首项为1的等比数列,所以341bbq,即38q,可得2q
,所以1112nnnbbq.(2)由题意可知,(1)2nnnS,12nnb,由已知,2167,83,nnnnnbncSlogbn为奇数为偶数,可得1672,2123,nnnncnnnn为奇数
为偶数,设{}nc的前2n项和中,奇数项的和为nP,偶数项的和为nQ,所以13521nnPcccc,2462nnQcccc,当n为奇数时,111(67)222(21)(23)2321nnnnncnnnn,所以2042642220135
2122222222424()()()()15195139414341141nnnnnnPccccnnnn,当n为偶数时,ncn,{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBB
AEMAAAwBFABAA=}#}9所以2462(22)2462(1)2nnnnQccccnnn,由24(1)41nnnTn,得44(1)1(1)4141nnn
nnnn,即(1)1(1)nnn,当n为偶数时,21nn对一切偶数成立,所以5,当n为奇数时,21nn对一切奇数成立,所以此时1,故对一切*nN恒成立,则15
,所以的取值范围是(1,5).22.【答案】(1)证明详情见解答.(2)证明详情见解答.(3)证明详情见解答.【解答】解:(1)证明:由条件可得()cossincosxxfxexexx,设()()gxfx,则()cossinsincossinsin(12)xxx
xxgxexexexexxxe,因为[0x,]2,所以()0gx,所以()gx单调递减,又(0)0g,所以()0gx,即()0fx所以()fx单调递减,又(0)0f,所以()0fx.(2)证明:由(1)当(0,5)x时,令()0gx
得x,2,3,4,所以当(0,)x时,()gx单调递减,当(,2)x时,()gx单调递增,当(2,3)x时,()gx单调递减,当(3,4)x时,()gx单调递增,当(4,5)
x时,()gx单调递减,又(0)0g,()110gee,2(2)10ge,3(3)10ge,4(4)10ge,5(5)10ge,所以存在(,2)a
,(2,3)b,(3,4)c,(4,5)d使得g(a)g(b)g(c)g(d)0,(0,)xa,()()0fxgx,()fx单调递减,(,)xab,()()0fxgx
,()fx单调递增,(,)xbc,()()0fxgx,()fx单调递减,(,)xcd,()()0fxgx,()fx单调递增,(,5)xd,()()0fxgx,()fx单调递减,又f(a)(0)0f,f(b)(2)0f,f(c)(3)0f
,f(d)(4)0f,(5)0f,所以1(,)xab,2(,)xbc,3(,)xcd,4(,5)xd,使得1234()()()()0fxfxfxfx,所以()fx在(0,5)上有4个
零点.{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}10(3)证明:由(2)知,1(,2)xa,又3()02f,所以132x,3
(,4)xc,又7()02f,所以372x,所以要证1423xxxx,即证422xx,即证422xx,因为4313(4)10322fe,(4)202f,所以4(43x,4)2
,又2213(2)10322fe,(2)202f,所以2(23x,2)2,所以42(23x,2)2,又因为(23x,2)2,()fx单调递减,又2233131(2)03222fee
,所以()0fx,所以()fx在(23x,2)2上单调递减,所以只需证42(2)()fxfx,又442244444(2)cos(2)sin(2)1cossin1xxfxexxexx
,又4()0fx,所以4244cossin10xexx,所以44442244442(2)coscoscos()0()xxxxfxexexxeefx,所以422xx,所以422xx
,综上所述,1423xxxx.{#{QQABRQ4QggCAAAAAAQgCAwHyCgIQkAACCIoOBBAEMAAAwBFABAA=}#}