【文档说明】青海省西宁市2021-2022学年高一上学期期中考试数学试题答案.pdf,共(2)页,356.552 KB,由小赞的店铺上传
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一、选择题题号123456789101112答案CCBCCBCCBCDD二、填空题13.414.215.①②16.f(x)=x34三、解答题(解答题的解法不唯一,以下是参考解答)17.(10分)解:由题意知A={-6,-5,-4,-3,-2,-1,0,1,2,
3,4,5,6}.(1)易知B∩C={3},故A∪(B∩C)={-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6}.(2)∵B∪C={1,2,3,4,5,6},∴∁A(B∪C)={-6,-5,-4,-3,-2,
-1,0},∴A∩[∁A(B∪C)]={-6,-5,-4,-3,-2,-1,0}18(12分)(log23+log53)(log35+log95)lg2+=(lg3lg2+lg3lg5)(lg5lg3+lg5lg9)∙lg2+1=lg3(lg2+lg5)lg2∙lg5∙lg5(lg3+lg9)
lg3∙lg9∙lg2+1=lg3+2lg32lg3+1=32+1=52.19.(12分)由已知对任意实数x,y都有f(xy)=f(x)+f(y).(1)令x=y=0,得f(0)=f(0)+f(0),∴f(0)=0.令x=y=1,得
f(1)=f(1)+f(1),∴f(1)=0.(2)令x=y=2,得f(4)=f(2)+f(2)=2f(2)=2a.令x=y=3,得f(9)=f(3)+f(3)=2f(3)=2b.令x=4,y=9,得f(36)=f(4×9)=f(4)+f(9)=2a
+2b.20.当a>1时,loga(2m)<loga(m+1)⇒2m>m+1⇒m>1,又{2m>0m+1>0,即m>0,所以m>1.当0<a<1时,loga(2m)<loga(m+1)⇒2m<m+1⇒m<1又{2m>0m+
1>0,即m>0,所以0<m<1.21.(1)∵f(x)是定义域为的奇函数,∴f(0)=0,即f(0)=223=0,解得=3或=1,又∵>0,∴=3f(x)=(2)猜想f(x)在上单调递增,证明:在定义域R上,设
x<x2,则f(x)f(x2)=+=()(1+),∵x<x2,即<,∴<0,1+>0,可得f(x)f(x2)<0,∵x<x2时,f(x)<f(x2),∴f(x)在上单调递增.22.(12分)(1)解x的取值需满足2x-1
≠0,则x≠0,即f(x)的定义域是(-∞,0)∪(0,+∞).(2)解由(1)知,f(x)的定义域是(-∞,0)∪(0,+∞).∵f(-x)=2--+2=2-2+2=222-,∴f(x)+f(-x)=2-+2+222-=-22-+1=0.∴f(-x)=-f(x).∴f(
x)是奇函数.