2..2函数的定义域和值域.pdf
1/9 本资料来源于七彩教育网http:/ 22 函数的定义域与值域【知识网络】1函数的定义域;2函数的值域【典型例题】例11)函数)13lg(13)(2xxxxf的定义域是 C)A,31)B(31,31)C(31,1)D(31,)提示:由10310 xx解得113x答案为 C.A|1x xB|2x xC|12x xx且D|12x xx或提示:11()1()111ff xf xx,11101xx,解得12xx且,答案为 C3)函数268ykxxk的定义域为 R,则k的取值范围是 B)A.09kk或 B.1k C.91k D.01k提示:2680kxxk恒成立,0k显然不符,0364(8)0kk k,解得:1k,选 B.12)yxxx;2232xyx;914xyx;xxycottan5)若的最大值是则yxyx43,122_5_ 提示:设cos,sinxy,则343cos4sin5sinxy(),其最大值为5例21)求下列函数的定义域:xxxxxxf02)1(65)(的定义域2)已知函数()f x的定义域是(,)a b,求函数()(31)(31)F xfxfx的定义域解:由函数解读式有意义,得2/9 0010652xxxxx321011230 xxxxxxx或或或故函数的定义域是),32,1()1,0(2)由113133311133abxaxbaxbabx 函数的定义域不可能为空集,必有1133ab,即2ba此时,1133abx,函数的定义域为 3131 ba,);例3求下列函数的值域:1)2432yxx;2)12yxx;3)221223xxyxx;4)35yxx;解:1)24(1)4yx,20(1)44x,20(1)42x224(1)44x所给函数的值域为 2,4,则x=212t212tyt21(1)12t,当1t时,max1y所给函数的值域为(,1.3)由已知得:2(21)(21)(31)0yxyxy*)当210y时,12y,代入*)式,不成立,12y当210y时,则:211312231102(21)4(21)(31)0102yyyyyyy 所给函数的值域为31,)1024)530503xxx得由函数定义域为 3,5 2222(3)(5)22 1(4)yxxx又当4x时,2max4y,当35x或时,2min2y224y0y22y文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q10文档编码:CH8K8J7A2R4 HB9E1E1I10Q2 ZU9U4V5F5Q103/9 所给2,2函数的值域为例 4已知函数2()3yf xxax在区间 1,1 上的最小值为3,求实数a的值解:43)2()(22aaxxfy1)min12(1)432aayfa当,即时,解得:7a2)当112a,即22a时,2mi n()3324aayf,解 得2 6a舍去)3)当12a,即2a时,min(1)43yfa,解得:7a综合1)2)3)可得:a=7【课内练习】1函数23)(xxxf的定义域为 B)A0,错误!B0,3 C3,0 D0,3)zwj2px3C3L 提示:由230 xx得:03x,答案为 B2函数251xyx的值域为 A5|2y y B|0y y C|25y yy且 D2|5y y提示:y)15(5252x,)15(52x 0,y52答案为 D3若函数()f x的定义域为,ab,且0ba,则函数()()()g xf xfx的定义域是 D)A,ab B,ba C,bb D,aa提示:由(0)axbbaaxb得:(0)axbbabxa即axa,答案为D4函数2211xyx的值域为 的值域是2,)提示:24(1)923(1)26(1)32(1)xyxxx,文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M64/9 当且仅当123(1)32(1)xxx即12x时取等号又函数无最大值,故函数值域为2,)7若一系列函数的解读式相同、值域相同,但其定义域不同,则称这些函数为“同族函数”,那么函数解读式为2yx、值域为 1,4 的“同族函数”共有 9 个.zwj2px3C3L 提示:设函数2yx的定义域为 D,其值域为 1,4,D的所有情形的个数,即是同族函数的个数,D的所有情形为:1,2,1,2,1,2,1,2,1,1,2,1,1,2,1,2,2,1,2,1,zwj2px3C3L 1,1,2,2共9个,答案为 98求下列函数的定义域:1)2311xxyx;2)12log(2)xyx解:(2,3 2)由12log(2)0 x,得:021x,即:12x,函数的定义域为(1,2)9求下列函数的值域:1)242(14)yxxx;2)xxysin2sin2;3)22436xxyxx解:1)2(2)2yx14x,当2x时,max2y,当4x时,min2y 所给函数的值域为 2,22)由xxysin2sin2解得:22sin1yxy,由|sin|1x得22|11yy两边平方后整理,得:231030yy,解得:133x,故所给函数的值域为1,33 若1y,代入 得:3x,25y函数的值域为:2|,15y yRyy且评注:本题中需要检验的原因是:函数22436xxyxx可化简为文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M65/9 1(3)2xyxx10已知函数12)(2axxxf在区间 1,2上的最大值为 4,求a的值解:22()()1yf xxaa1)当12a,即12a时,在2x时函数有最大值,(2)544fa,解得14a,适合;2)当12a,即12a时,在1x时函数有最大值,(1)224fa,解得1a,适合综上所述:14a或1a作业本A组1设IR,已知2()lg(32)f xxx的定义域为 F,函数()lg(1)lg(2)g xxx的定义域为 G,那么 GUIC F等于 B(,2 C(1,D(1,2U(2,提示:由2320 xx得:21xx或,F(,1(2,IC F1,2,又由1020 xx得2x,G(2,GUIC F1,答案为 C2已知函数)(xf的定义域为 0,4,求函数)()3(2xfxfy的定义域为C)A 2,1 B1,2 C 2,1 D 1,2提示:由题意有404302xx解得12x,故此函数的定义域为 2,1,答案为 C3若a1,则11aa的最小值是 x2(y2xy30 当y 2时,(y224(y2(y30,解得2y310;当y2时,*)不成立综上所述:2y310.函数的值域为10(2,37求函数xxycoslg252的定义域解:由0cos0252xx得:)(222255Zkkxkx函数的定义域为33 5,)(,)(,522228已知函数2()23f xxx在0,a(0)a上的最大值为 3,最小值为 2,求实数a的取值范围解:2()(1)2f xx,1)当12a,即2a时,2(1)2()233ff aaa,解得:20(aa或舍);2)当12aa,即12a时,(1)2(0)3ff,适合题意;3)当1a时,2(0)3()232ff aaa,解得:1a舍)综上所述:12aB组1若函数()f x的定义域为 2,2,则函数()fx的定义域是 D)A4,4 B2,2 C 0,2 D 0,4zwj2px3C3L 提示:()fx中的x相当于()f x中的x,则22x,04x,答案为 D文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M67/9 2已知函数1()lg1xf xx的定义域为 A,函数()lg(1)lg(1)g xxx的定义域为 B,则下述关于 A、B的关系中,不正确的为 D)AAB BAB=B CA B=B DB错误!Azwj2px3C3L 提示:由101xx得:11x,|11Axx,由1010 xx得:11x,|11Axx,AB,显然,答案为 D3下列结论中正确的是 D)A当2x时,1xx的最小值为 2 B02x时,22xx无最大值C当0 x时,12xxD当1x时,1lg2lgxx提示:A中,12xx,但12xxx无解;B中,22xx为增函数,2x时可取得最大值;C中,0 x时不成立;D为真,答案为 D4函数(63)(02)yxxx的值域是0,3提示:2(2)3(2)3 32xxyxx,当且仅当022xxx,即1x时取等号又0y,故函数的值域为0,35已知函数22(1)1xyaxax的定义域是R,则实数a的范围是32232 2a提示:对x,2(1)10axax恒成立,0a时,显然不符合题意;20(1)40aaa,解得:32232 2a6已知函数22()lg(1)(1)1,f xaxax若()f x的值域为(,),求实数a的取值范围。解:设22(1)(1)1taxax,()(,)f x,(0,)t即t只要能取到(0,)上的任何实数即满足要求。由右图若2(1)0a,则22210513(1)4(1)0aaaa;若210a,则1a,当1,21atx时满足要求文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M68/9 当1,1at时不合,舍去)综上所述:513a7已知()f x的值域是34,89,试求函数()()12()yg xf xf x的值域解:34()89f x1112()94f x1112()32f x令1112()()32f xtt,则21()(1)2f xt2211(1)(1)122ytttminmax17173928tyty当时,当时,77,98y8已知二次函数2()(0,)f xxbxc bcR若()f x的定义域为 1,0时,值域也是 1,0,符合上述条件的函数()f x是否存在?若存在,求出()f x的解读式;若不存在,请说明理由zwj2px3C3L 解:假设符合条件的()f x存在函数图像的对称轴是2bx,又0b,02b1)当1022b时,即01b,函数当2bx时,有最小值1,则22()1,1242(1)010bbbfcfbc0,4,().13bbcc或舍去2)当1122b时,即12b时,则2,2,()1,().200(1)0bbbfccf或都舍去3)当12b,即2b时,函数在 1,0上单调递增,则(1)1,2(0)00fbfc综上所述,符合条件的函数有2个:22()1()2f xxf xxx或文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ10X7X4F2M6文档编码:CS3I10K7P8F6 HC7T6W3L5X6 ZJ1