山西省大同市2017-2018学年高一数学上学期期中试题(扫描版)2017~2018学年度第一学期期中试卷答案1~5BADBC6~10ADCAD11~12BC13.14.15415.1,11616.③④17.解:①由已知:ⅰ.B时,21aa即1a……………………………………………………2分ⅱ.B时212213aaaa12a……………………………………………5分综合ⅰ、ⅱ知,2a…………………………………………………………………6分②由ABABAⅰ.B21aa1a………………………………………………8分ⅱ.B21321-2aaaa或1132aaa或即:3a………………………………………………………………………………11分综合ⅰ、ⅱ知,3a或1a………………………………………………………12分18.解:由已知,xR①1111()()1111xxxxxxxxxxaaaaafxfxaaaaa()fx是奇函数……………………………………………………………………………4分②由1122()1111xxxxxaayfxaaa……………………………………………8分,1xRa0xa11xa1011xa2201xa21111xa1,1y…………………………………………………………………………………12分19.解:①由已知:(1)25(2)462fbcbfc324bcbc21bc2()21fxxx…………………………………………………………………………4分②任取1x、2x0,1,令12xx12121211121212121212122211()()(21)(21)21212fxfxxxxxxxxxxxxxxxxxxxxx……………8分1x、2x0,1且12xx,1201xx120xx1210xx12121212()(1)()()20xxxxfxfxxx即12()()fxfx2()21fxxx在0,1上单调递减…………………………………………………12分20.解:①.由已知:53053mm为偶数5353mm为偶数mN1m2()fxx…………………4分②.由①21()log()2agxxax在2,5为增函数ⅰ.1a时,logayu在(0,)u上单调递增,212uxax在2,5上单调递增24(2)40aua4a14a………………………………8分ⅱ.01a时,logayu在(0,)u上单调递减,212,52uxax在上单调递减545(5)2502aaua…………………………………………………10分综合ⅰ和ⅱ知,14a……………………………………………………………………12分(实验班)解:由已知:令43041xx则2(4)4()(4)(4)fxfxxx21()(712)4fxxx……………………………………………………………………2分令32x142x521(4)4()2xfxfx5211()42xfx………………………………………………………………………4分即2521(712)(43)4()11(32)42xxxxfxx易知43x时,min116y……………………………………………………………6分32x时,min14y……………………………………………………………8分故:11424tt………………………………………………………………………………9分2204ttt(2)(1)0(0)tttt201tt或…………………………………………………………………………10分