1、一、选择题1若log2a0,()b1,则有()Aa1,b0 Ba1,b0C0a1,b0 D0a1,b02若不等式x2x0的解集为M,函数f(x)ln(1|x|)的定义域为N,则MN为()A0,1) B(0,1) C0,1 D(1,03已知函数yg(x)的图象与函数y3x的图象关于直线yx对称,则g(2)的值为()A9 B. C. Dlog324(2011宁德模拟)函数ylg|x1|的图象是()5设f(x)lg(a)是奇函数,则使f(x)0的x的取值范围是()A(1,0) B(0,1)C(,0) D(,0)(1,)二、填空题6设alog3,blog2,clog3,则a,b,c的大小关系是_7y(
2、log a)x在R上为减函数,则a_.8(2011大连模拟)已知函数f(x)满足:当x4时,f(x)()x;当x4时,f(x)f(x1)则f(2log23)_.三、解答题9(2010上海高考)已知0x,化简:lg(cos xtan x12sin2)lgcos(x)lg(1sin 2x)10设函数f(x)loga(1),其中0a1.(1)证明:f(x)是(a,)上的减函数;(2)解不等式f(x)1.11已知函数f(x)log4(4x1)2kx(kR)是偶函数(1)求k的值(2)若方程f(x)m有解,求m的取值范围答案及解析1.【解】由log2a0,得0a1,由()b1,知b0.【答案】D2.【解
3、】易得M0,1,N(1,1),MN0,1)【答案】A3.【解】易知g(x)log3x,g(2)log32.【答案】D4.【解】ylg|x1|选A.【答案】A5.【解】f(x)是奇函数,f(0)0,a1,f(x)lg,由f(x)0,得01,1x0.【答案】A6.【解】alog31,blog2(,1),clog3log32,abc.【答案】abc7.【解】使0loga1,得a1.【答案】(,1)8.【解】23422,1log232.32log234,f(2log23)f(3log23)f(log224),()log2242log2242log2.【答案】9.【解】0x,原式lg(sin xcos
4、x)lg(cos xsin x)lg(1sin 2x)lglg 0.10.【证明】(1)设0ax1x2,g(x)1,则g(x1)g(x2)110,g(x1)g(x2)又0a1,f(x1)f(x2)f(x)在(a,)上是减函数(2)loga(1)1,01a,1a1,又0a0,从而ax.不等式的解集为x|ax11.【解】(1)由函数f(x)是偶函数,可知f(x)f(x),log4(4x1)2kxlog4(4x1)2kx,log44kx,log44x4kx,x4kx,即(14k)x0,对一切xR恒成立,k.(2)由mf(x)log4(4x1)xlog4log4(2x),2x2,mlog42.故要使方程f(x)m有解,m的取值范围为,)