专转本数学函数的极限与连续模拟试题练习
一、 选择题
1.下列各组函数中是相同函数一组的是 ( ) A.f(x)?xx?1,g(x)?x3?x2 B.f(x)?arcsin(sinx),g(x)?x
C.f(x)?1?cos2x,g(x)?2sin2x D.f(x)?lnx2,g(x)?2lnx 2.y?4?x?ln(x?1)的连续区间为 ( )
A.(0,4] B.(1,4] C.(1,4) D.(1,??) 3.在[??2,?]上函数f(x)?xsinx?2是 ( ) 2A.奇函数 B.偶函数 C.有界函数 D.周期函数
4.设函数f(x)的定义域是[0,1],则函数f(3x?1)的定义域为( )
11121,] B.[,] C.[0,1] D.[?,1] 33333125.设f(x)?x?arccot,则x?1是f(x)的 ( )
x?1 A.[?A.可去间断点 B.跳跃间断点 C.无穷间断点 D.连续点
1?x?6.函数f(x)??1?e??x?1x?0在x?0间断是因为 ( )
x?0 A.f(x)在x?0无定义 B.
lim?f(x)和limf(x)都不存在 x?0x?0?x?0 C.limf(x)不存在 D.limf(x)?f(0)
x?07.下列命题正确的是 ( ) A.数列有界必有极限; B.若limf(x)存在,则f(x)有界;
x??C.若limf(x)存在,则f(x)有界;
x?x0D.若limf(x)?A,则f(x)?A是当x??时的无穷小量
x???sin2x?x??8.设f(x)??1??e?x??x?0x?0,则limf(x)= ( )
x?0x?0A.1 B.不存在 C.2 D.-2
3??9.若lim?1??n??n??A.
kn?e?1,则k? ( )
11 B.? C.3 D.-3 3310.当x?0时,下列函数是无穷大量的是 ( )
13x2A.e B.ln(1?x) C.2 D.cotx
xx?111.下列函数中的连续函数是 ( )
1x?1?x2??A.f(x)??1?x?2??x?1x?1 B.f(x)???ln(x?3)x.?0 x?0?x?2?1?x?1?xsin(x?3)x?0?x?0C.f(x)?? D. f(x)??xxex?0??0x?0?二、填空题 1.设f(x)???x?1?1x.?22?x?3,则f(x?1)的定义域为___________.
2.若g(x)?x?2,且f(g(x))?x?35(x?1),则f()?_____________. x?12x2?x?6(x?1)20(3x?2)103.lim=___________;lim=___________. 230x?2x??x?4(1?x)4.limsin(x?2)?___________.limx[ln(1?x)?lnx]=___________. 2x???x??2x?425.当x?0时,mx与1?cosx是等价无穷小,则m? ___________.
6.设函数f(x)?a(a?0,a?1),
x1[f(1)?f(2)???f(n)]?_________.
x??n2x?2kx)?e3,则k? ___________. 7.若lim(x??x?klim1??(cosx)x2若函数f(x)???k?x?0 在x?0连续,则k?___________.
x?0?x2?kx?18.若lim??x???x?1??x???3,则k? ___________. ?x?19.设f(x)在x?1处连续,且f(1)?3,则limf(x)[___________.
12?2]? x?1x?1x2?910.函数f(x)?2的无穷间断点为________________.
x?x?6三、求下列函数的极限 1.limx?12x?1?3x?22; 2.lim2x?1?3xx?2x?2sinx2x???;
3.limx(x?1?x); 4.limx???x?1sin(x?1); 2x?x?25.lim(x?0x4?e1xx2?1ex?e?x?2(4?cosx)]; ?); 6.lim[3x??x?x2?2x215?xx7.lim2; 8.lim(1?2x)x;
x?0x?0(x?x?2cosx)ln(1?x)5sinx?x2sin9.limln(cosx)1?sinx?cosxlim; 10.; 2x?0x?0cos2x?sin2x?1x11ln(cosx)3arcsin2x?x11.lim; 12.lim?ex[sin2??e].
x?02cos2x?2x?0xx?tanax?x???2四、已知f(x)??e?2?(1?x)x??x?0x?0 在x?0处连续,求a的取值. x?0