函数、极限与连续典型例题
1.填空题
(1)函数f (x ) =1的定义域是 . ln(x -2)
1+4-x 2的定义域是. ln(x +2)
. (2)函数f (x ) =(3)函数f (x +2) =x 2+4x +7,则f (x ) =
3⎧⎪x sin +1, x
(5)函数f (x -1) =x 2-2x ,则f (x ) =
x 2-2x -3(6)函数y =的间断点是. x +1
1= x →∞x
sin 4x =2,则k = . (8)若lim x →0sin kx (7)lim x sin
2.单项选择题
e -x +e x
(1)设函数y =,则该函数是( ). 2
A .奇函数 B .偶函数 C .非奇非偶函数 D.既奇又偶函数
(2)下列函数中为奇函数是( ).
e -x +e x
2A .x sin x B . C .ln(x ++x 2) D .x +x 2
x +ln(x +5) 的定义域为( ). x +4
A .x >-5 B.x ≠-4 C.x >-5且x ≠0 D.x >-5且x ≠-4 (3)函数y =
2(4)设f (x +1) =x -1,则f (x ) =( )
2A .x (x +1) B.x
C .x (x -2) D.(x +2)(x -1)
⎧e x +2, x ≠0(5)当k =( )时,函数f (x ) =⎨在x =0处连续. x =0⎩k ,
A .0 B .1 C .2 D .3
⎧x 2+1, x ≠0(6)当k =( )时,函数f (x ) =⎨,在x =0处连续. x =0⎩k ,
A .0 B .1 C.2 D.-1
(7)函数f (x ) =x -3的间断点是( ) 2x -3x +2
A .x =1, x =2 B
C .x =1, x =2, x =3 D
3.计算题
(1)lim x 2-3x +2
x →2x 2-4.
(2)lim x 2-9
x →3x 2-2x -3
(3)lim x 2-6x +8
x →4x 2-5x +4
4)计算极限lim -x -1
x →0x .
(5)计算极限lim -x -1
x →0sin 4x
.x =3 .无间断点 (
函数、极限与连续典型例题
1.填空题
(1)函数f (x ) =1的定义域是 . ln(x -2)
1+4-x 2的定义域是. ln(x +2)
. (2)函数f (x ) =(3)函数f (x +2) =x 2+4x +7,则f (x ) =
3⎧⎪x sin +1, x
(5)函数f (x -1) =x 2-2x ,则f (x ) =
x 2-2x -3(6)函数y =的间断点是. x +1
1= x →∞x
sin 4x =2,则k = . (8)若lim x →0sin kx (7)lim x sin
2.单项选择题
e -x +e x
(1)设函数y =,则该函数是( ). 2
A .奇函数 B .偶函数 C .非奇非偶函数 D.既奇又偶函数
(2)下列函数中为奇函数是( ).
e -x +e x
2A .x sin x B . C .ln(x ++x 2) D .x +x 2
x +ln(x +5) 的定义域为( ). x +4
A .x >-5 B.x ≠-4 C.x >-5且x ≠0 D.x >-5且x ≠-4 (3)函数y =
2(4)设f (x +1) =x -1,则f (x ) =( )
2A .x (x +1) B.x
C .x (x -2) D.(x +2)(x -1)
⎧e x +2, x ≠0(5)当k =( )时,函数f (x ) =⎨在x =0处连续. x =0⎩k ,
A .0 B .1 C .2 D .3
⎧x 2+1, x ≠0(6)当k =( )时,函数f (x ) =⎨,在x =0处连续. x =0⎩k ,
A .0 B .1 C.2 D.-1
(7)函数f (x ) =x -3的间断点是( ) 2x -3x +2
A .x =1, x =2 B
C .x =1, x =2, x =3 D
3.计算题
(1)lim x 2-3x +2
x →2x 2-4.
(2)lim x 2-9
x →3x 2-2x -3
(3)lim x 2-6x +8
x →4x 2-5x +4
4)计算极限lim -x -1
x →0x .
(5)计算极限lim -x -1
x →0sin 4x
.x =3 .无间断点 (