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三峡名校联盟2022年秋季高2025届数学参考答案及评分细则一、单项选择题12345678BDBCCBBA二、多项选择题9101112ACADABDABC12.ABC解:由2336xy可得:2log36x,3log36y,对于A:363636111log3log2
log62xyxyyx,所以2xyxy,故选项A正确;对于B:2222log36log4log92log9x,222log8log9log16,即23log94,
所以22log95,6x,3333log36log9log42log4y,333loglog349log即31log42,所以32log43,4y,所以8xy,21
6xyxy,故选项B正确;对于C:22log3622log3x,33log3622log2y,所以2322142log3log242log3log3xy,令2log31,2t,则142xytt
在1,2t上单调递增,所以114242292xytt,故选项C正确;对于D:22log95,6x,32log43,4y,所以22525x,
2239y,所以2234xy,故选项D不正确,故选:ABC.三、填空题13:xe(答案不唯一例:)1(aax)14:1315:1620;41516:33四、解答题17.解:(1)22T.....2分(2)令.,2242Zkkx则.,8Zkkx....
.4分当.,8Zkkx函数有)(xf最大值21......6分(3)令Z42x。Zysin21在Zkkk],2222[,上单调递增。kxk224222,kx
k883.......8分22,x.0时当k883x.]8,83[)(的单增区间:函数xf.....10分18.解:(1)由题意,52)1(2222yxr,5525
2sinry.....2分212tanxy,.....4分554)2(552tansin......6分分)(8..........5551cos2rx)sin().tan()2sin()23cos()2
tan()27cos()2sin()(f)sin).(tan((sin)sin()tan()sin(coscos55......12分
注:第一问6分,第二问6分.第二问化简4分,6个三角函数值错一个扣1分,直到扣完。如果第一问求了55cos第二问可以不求.19.解:选①,21log2x,4log1log22x,410x,31x.3
1xxB.选②16211x,410222x,410x,31x.31xxB.......3分(1)当0a时,11xxA,ACR1,1xxx或,BACR
)(31xx.......6分(2)“xA”是“xB”的充分不必要条件,①A,.121aa2a.......8分②,A2a31211aa或31211aa.10a.综
上所述:2a或10a.......12分注:第二问没取等号扣1分,20.解:)3(log)(2axxxfa,)10(aa且。(1)当,4a)34(log)(24xxxf,令,0342xx,0)3)(1(xx.1,3xx或)34(lo
g)(24xxxf定义域:),(3),(1令342xxt,ty4log.342xxt在),(3单减,在),(1单增。ty4log在),(0单增.......2
分)34(log)(24xxxf单增区间:),(1.......3分)34(log)(24xxxf单减区间:),(3.......4分(2)若函数,的定义域为Rxfy)(恒成立,则032axx0122a,3232a,..
....7分又10aa且.321,10aa或.......8分(3)函数,,的值域为1)(xfytyalog令,32axxt4343)2(32222aaaxaxxt结合tyalog
单调性和图像。1a...10分此时32axxt值域,,aaa43201242aa,,0)2)(6(aa2,1aa.......12分21.解:(1)由题意可得250230,0210()203048048030,251xxxfxWxxxxxx
,即25030100,021648030,251xxxfxxxx,所以函数()fx的函数关系式为25030100,021648030,251xxxfxxxx.....
..5分(2)当02x时,25030100fxxx为开口向上的抛物线,对称轴为30325010x,所以当2x时2max2502302100240fxf,......7分当25x时,
1616164803048030130510301111fxxxxxxx1651030212701xx,......10分当且仅当1611xx即3x
时等号成立,此时min270fx,......11分综上所述:当投入的肥料费用为31030元时,单株水果树获得的利润最大为270元.......12分.22.解:(1)令.0yx0)0(),0()0()00(ffff.令,xy),()()(xfxfxxf
,0)()(xfxf)(xf是奇函数.......2分(2)令,21,xxxyx则21xxy.不妨设,21xx),()()(yfxfyxf),()()(2121xxfxfxf)()()(2121xxfxf
xf,0x时,有.0)(xf0)()(21xfxf,.)(上单调递增在Rxf......4分令21yx,则2)21(2)1(ff,令1yx,则4)1(2)2(ff,4)2(f.)2(4)()552525(,0222k
kfkkftttft都有,.)(上单调递增在Rxf2552525,022kktttt都有,......5分设,]311)1[(251)1(251)1(3)1(252555)(22tttttttttu)1(1w
tw令,.11)单调递增,在(ww,21ww51]311)1[(251)(tttu.......6分,252kk,032kk,0)2131)(2131(kk或,2131k.2131k......7
分(3)23)1(f,令1yx,则3)1(2)2(ff,3)2(f.3)2(f.03]2)()3())([(2mxgmxgf)0(]22)()3())([(2fmxgmxgf.)(上单调递增在Rxf022)()3
())((2mxgmxg......8分有三个不同的零点,,令txg)(022)3(2mtmt.12xt.21012,,交点个数为与xyty.210022)3(2,,的解的个数为m
tmt。必有两个不同解212,022)3(ttmtmt且),(101t,.1,02tttt或①舍去)方程,(,2,02,10122tttmt,......9分②.32,032353
4,022311122成立方程,tttmmmt......10分③02213(10220)3(022mmmm).134m综上所述:.134m......12分获得更多资源请扫码加入享学资源网微信公众号ww
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