2019年高考数学(理)真题和模拟题分项汇编2 函数的概念与基本初等函数I (解析版)

Ia，b20.2，c0.32．a．cbcabacbB．D．bcaBalog0.2log10,b0.2221,0220.300c0c0.20.21,即cb则a．．log2blog0.20.50.2，cabc,,a，50.5．a．bcbcaabcB．D．cabA1log2log5a，255blog0.2log0.252，0.50.5121，cc01cba..−B3baa−33D│Ca2,b1abln()0abA；19333B；由取21ab2b|1||2|aD；x3bC.y．ab33a3b35E−=mm1（−mEk2E21kk2−ABD−5Emm1，2E212m1.45,m26.7令则，21E22mm(1E55212E.1E2.xx在[,]xx2．B．2D．Dsin(x)(x)xxf(x)f(x)()fxcos(x)(x)2xx2π1πf()242ππ21,(π)0D又fππ2π21()22．2x36,6y在22xx．B．．D．B2x32(x)32x3f(x)f(x)f(x)()fxy22x22x22xxxx．3243；又f2244263f7，2266．11ylog(x)y，ax2aD10a1yyaxax121yx(D2a11ya当ayxax121yx(）.2aa.年1月3L24LM１，R２M2MMM(Rr)L2.r121r(Rr)2r2R3r345设．．3r(1)2RMMMRB．D．RR222M113MMR2233MM11D【解析】由MrrR，RMrM(Rr)121，(Rr)R322MMM)121，)R222R2R2M1543[(1)]3，即212)2(1)2MM2，33M1MrR.233M10,+fxR132．f3f（2f（2）234123．f3f（2f（2）3245132．f（2f（2f））2334123．f（2f（2f3234C1fx(log)f(log4)fR．4332332233log4log31,1222log422，02333fx又∴2332(log4)f2f2f，314322f2f2flog.即33．(x)f(x1)2f(x)x(0,1]fR8f(x)x(x1)x(,m]f(x)m9．9B．73,,,,4．5D．823Bfx2fx)f(x)2f(x1)，．1(0,1]()(1)[,0]fxxx∵x∴x；4121f(x)2f(xx1)(xx，；∴xx1f(x)2f(x4(x2)(x3)[，，6897383x4(x2)(x3)x1x2当，，87x(,m]f(x)m.937,则m.3x8.9x,x0a,bRf(x)yf(x)b11x(a1)xax,x032323B<D>C0x则b，当b3+b3，yx2(a1)x，当1b则b当>10得7令0得2.b3b2＞∴＜0且，＜＞，则>．当0xbb376xx2y▲.【答案】[1,7].x76xx0即x6x701x7，22[.(x)0()efxf(ln2)8afx若8．3f(x)0()efxx，ln2(0,1)f(ln2)8，，ealn28，eln23ln2，aa3a3．eefxa为常数）．若）为奇函数，则；xx若（．fxRa1,0()0fxaaa.fxeefxfx,eeeex即x，xxxxa1ee0x即xx10a1.则afxee()ee0在Rx是Rfxaxxxe即a在R2xe02x0，又a,0a..2R()3tR|ft2)ft)fxaxx15a，3a43923Rftft|(2)()t，23|at2)t2)att33，23|2att422，222att422，332即43att42，34tt4t1)11a0由22.34.a3|a(t2)(t2)att|332.3x．1xx．608010130.xy120120y80%当y当yyx80%y70%8yx7y,xy即，8y8x15.min10.(x),g(x)f(x)g(x)，fR(x2),0x1k(x)x(0,2]f(x)1(x1)2()2f.当，gx1,1x22(x)g(x)xf有8k▲.12,34(x)g(x)，f1(x)(1x2,3x4,5x6,7x8)f(x)1(x2g的2f(x)g(x)有22x(x)g(x)xf有8与g(x)k(xx2则f(x)1(x,x2|k|21由y2k0kk(，k2141(k，312∴，k341112f(x)g(x)，.8k在34(x)g(x)，f.(x)23xfx是））B）D）B(x)23xfx(2)260f(1)230，，f且f，21..(0,)1x3|x|yy．y．yB．D．|x|xB1yxy2x||，，y|x|1yx(0,)y|x|.y|x|.12log1,0xxf3fx24,x0xf329BDBlog1,0xxfx2，4,x0xf(3)flog3log443．∴222．4．B0D21A.．.(x)(x3xf223．(,(,)B．23(,)D．(4,)．2A3x4，fxx22则x23x40(x4)(x1)0x4或x1，13fxx4或x1，logxfxyx2x34由y当x23(,)34yx2x2fxfx,1x3x42.2.1(x)()13fRf，401(x)(x)mm当x．f2B0D21C1f(x)f()1R，40(x)(x)m且xf，211fm2m1∴，424∴m1．．.．．B．D．在是D.在在是在14.x4fx41x．D．D(x)xx444fxf(x)f(x)，，414141xxxf(x)By9256255(3),f(4),ff，f70C在x.fxfxy是15．fxxfxB．xeeeexxxxxeeee．fxD．fxxxxxxC0（A（；xfxfxx当0（B中0fx，xfxxeexxeexxDfx，x．，，．B．D．．C，，，∴，，又在.16.恒．B．D．．C令，在，，，故.．.；或2,xax(x)5fx,xaf(x)数a,0,1．．B．D．1,0,D2,xaxf(x)x,xa17f(x)．af(x)f(x为5y,Rfxfxfx10xx1f121.若xx2122112．B．)12．)D．((8,)Afxfx0xx1yfx当x1()21xx1221(xyf(x)当x1yf(x)1fxf1f(1，logx102当x211flogx1flogxf(x1xx2；22222logx12当x2fx1fxf(3)x3x8,2x8，2221812fx1.2．.f(x),,y，DI，xxDxx，I1212f(x)f(x)(f(x)f(x))(xx)0(0)f(x)f(x)若若21y是Dxx212121f(x)f(x)(f(x)f(x))(xx)0(0)21y是D.xx2121212(x2)f(x)在，上f(0)03)0ffx22(，)(2)(2)．．B．D．332222(，)()()3333Df(x2)f(x)x2f得(0)0f(4)0，2f(x)f(x)又在在23x2x0即3)03)fxf得23x4，fx2；3x223x2x0即3)0xf3)23x0xfxf当得，322(，)()f3x)0.33.在区间[0fxR19yfx1faf2且x1aa21410,B．,．414．D．4,,4Cfxyfx11xyfx[0fxf|a|f2|loga2，2212loga2a，4即2414,4即.a．.且B．．．D．A.又.20有．.1,x0x2Bfxx，2,x0x1gxxx2bagbfa2b237,．．B．D．22373,42,22A1,x0x2fxx，2,x0x1fx2x1fx22；0x1x2111xfx0xx2，当xxxx1xx1x.，..f(x)(x)flog(x)211(,0)22x10(20，x121x0.21(,0)2f(x)则..5为．，..则.()fxxf(x)f(2ax)bf(x)，abxx1＋ab2f(x)