10、,4,5,6,7},M={3,4,5,7},N={2,4,5,6},则()A.#A/V^{4,6}B.A2N=UC.Mu.,片〃D.答案:Bf
11、x-l
12、(x<0)5.若/«='7/则/[/(一1)]等于()[log?x(x>Q)A.-1B.2C・1D.0答案:c6.使{0,l}UM=MwA{0,1,2,34,5}=二M同时成立的集合M个数是()A.16B.15C.8D.7答案:A7.已知二l-2x,1兀21=(x^0),则f(±)等于()X2A.1B.3C.15D.30答案:c8.已知全集U=(0,1,2,3,4,5,6,
13、7,8,9),集合A=(0,1,3,5,8},集合B二{2,4,5,6,8},(cM)n(C"B)=()A.{5,8}B.{7,9}C.{0,1,3}D.{2,4,6}答案:B9.设集合A={x
14、-3<2x-l<3},集合B为函数y=lg(x-l)的定义域,则AcB二()A.1,2.C.1,2.D.1,2答案:D10.设函数f3是(一oo,+00)上的减函数,又若&WR,则()A.f(a)>f(2日)B.f(a2)(a)C.f(/+臼)(臼)D.f(/+l)15、B是/的子集,若AAB={1,2,3},就称(A,B)为好集,那么所有“好集”的个数为()A.6!B.62C.26D.36答案:D12.已知集合M=t
16、x>0),N=R
17、—1H},则MJN=()A.xx>-1}B.[r
18、x<2}C.{a
19、020、2/:-115.
21、若/(劝是R上的减函数,且/(0)=3,/(3)=-1,设P=W
22、/(x+/)-l
23、v2},Q={x/(x)<-1},若“xeQ”是“xgP”的必要不充分条件,则实数/的取值范围是答案:t<-316.己知集合U={1,2,3,4,5),A二{2,4},B={4,5},则An(QB)=答案:{2}三、解答题17.已知A={x-22m-l,即m<2时,B=满足BcA,即m<2;当m+l=2m-l,即m=2时,B={3},满足ByA,即m=2;加
24、+1n—2当小<2心,即心时,由叱A,得加七5即2<必3;m<318.设集合A—{x
25、/+<3^—12=0},〃={”#+加+c=0},且AHB,AUB={—3,4},AHB={—3},求臼、b、c的值.答案:VJA^={-3},且一3WB,将一3代入方程:x+ax~12=0中,得a=—1,从而A={—3,4}.将一3代入方程x+bx~~c=0,得3b—c=9.・・%U〃={—3,4},・・・/U〃=/,BQA.・・"纭儿・・・〃={-3}.・••方程#+bx+c=0的判別式厶=Z/—4c=0,30—c=9①Jf-4c=
26、0②由①得c=3方一9,代入②整理得:(方一6)2=0,・:方=6,c=9.故日=—1,方=6,c=9.孑一2曰+2,才+孑+3日+7},若/C〃={2,5},求19.己知:集合力={2,4,才一2孑一日+7},〃={一4,曰+3,实数日的值,并求AUR答案:・・%门〃={2,5},・・・5G,A={2,4,5},由已知可得才一2/—日+7=5,才一2#—日+2=0,.:(孑一1)(日一2)=0,・••日=2或日=±1.①当3=2时,〃={—4,5,2,25},加〃={2,5},与题设相符;②当臼=1时,〃={一4,4,1
27、,12},AnB={4},与题设矛盾;③当臼=一1时,〃={一4,2,5,4},AHB={2,4,5},与题设矛盾.综合①②③知:臼=2,AUB=(2,4,5}U(-4,5,2,25}={-4,2,4,5,25}.2°*己知")是*上白'J偶两数’口在(°”°°)上单调递增’开XL'(x)〈°刘一切成上