【文档说明】内蒙古通辽市开鲁县第一中学2020-2021学年高一上学期第一次月考数学试题(理)+扫描版含答案.docx,共(7)页,761.926 KB,由小赞的店铺上传
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高一月考试题答案2020.10一、选择题1.A2.A3.C4.B5.C6.A7.D8.C9.B10.D11.B12.C二、填空题13.43314.1615.16.(4,0−;三、解答题17.(1)22
310xx−+−等价于22310xx−+等价于()()2110xx−−,解得:1x或12x,所以不等式的解集为()1,1,2−+;(2)(2)∵1123xx+−,∴11023xx+−−,∴4023xx−+−,即4032x
x−−.此不等式等价于()3402xx−−且x-32≠0,解得32x或4x,∴原不等式的解集为32xx或4x.18.(1)()()61xx+−(2)()()611xx−+(3)()()()()2222281262
xxxxxxxx+−++=+−+−(3)(2)(2)(1)xxxx=+−+−.(4)(1)(3)(2)xxx−+−19.根据一元二次方程根与系数的关系,得12123,1xxxx+=−=−.(1)∵2221212122xxxxxx−=+−2a−()2212124(3)
4(1)13xxxx=+−=−−−=∴1213xx−=.(2)()()2222121212222222121212211(3)2(1)11(1)xxxxxxxxxxxx+−+−−−+====−.(3)()()()()
23322121122121212123xxxxxxxxxxxxxx=+−+=++−+2(3)(3)3(1)36=−−−−=−.20.(1)∵25Axx=−,*xN∴1,2,3,
4,5A=,∴集合A的真子集的个数为52131−=个.(2))∵BA;∴①B=时,121mm−+,解得2m−;②B时,212215mmm−−−+,解得12m−,综上可得m的取值范围为(),21,2
−−−.21.解:(1)由题意得11121112aaa−−−=−−−−=,解得2a=−,故原不等式等价于2301xx−+−„,即(23)(1)010xxx−−−…所以不等式的解集为3
(,1),2−+.(2)当0a=时,原不等式可化为10x+,解集为(,1]−−;当0a时,原不等式可化为1(1)0xxa−+…,解集为1(,1],a−−+;当0a时,原不等式可化为1(1)0xxa−+„,当11a
−,即1a−时,解集为11,a−;当11a=−,即1a=−时,解集为1−;当11a−,即10a−时,解集为1,1a−.22.解:()222()266fxxaxaxaaa=−+−−=−−+−−,图象开口向下,对称轴
为xa=,当1a−时,()fx在[1,2]−单调递减,当1x=−时,()()max1730fxfa=−=−−,解得73a−,即713a−−;当12a−时,()fx在[1,2]−先增后减,当xa=时,()()2max60fxfaaa==−−,解得23a
−,即12a−;当2a时,()fx在[1,2]−单调递增,当2x=时,()()max23100fxfa==−,解得103a,即1023a,综上所述,71033a−