(ii) lim : j(x) :
2
(x) J
m
(x) = 0。.....................................................................................................................................29
若 lim f (x) =0,且-: 0,当 x U(x
0
,、)时 f(x)屮 0, 则 lim........................................................................................................29
定义
1
若 lim f(x) = f(x
0
),称 f (x)在 x =冷处连续。.............................................................................................................29
3 若 lim f (x) = A, lim...................................................................................................................................................34
lim f ( (x))令(x) 二 ulim f (u) 二 A。.................................................................................................................................34
lim f (x) 上 g (x) L lim f (x) 士 lim g(x) ; ( 2) lim f (x) g (x^ - lim f (x) lim g(x);..........................................................34
lim cf (x) 二 Clim f (x) ;又若 lim g(x) =0,则...................................................................................................................34
§ 2.3 解题基本方法与技巧...................................................................................................................................................39
lim f (x) =0, lim g(x) =0 ;.............................................................................................................................................40
n
f(x
^-n
g(x
^
:
:;........................................................................................................................................................................42
lim f (x) 二 f (x
0
)............................................................................................................................................................42
2. 若 lim f (x) 二 A, lim g(x) 二 B,则................................................................................................................................42
= e-
:
.....................................................................................................................................................................................45
lim
ln(1
x)-
x
.............................................................................................................................................................................49
(>........................................................................................................................................................................................49
2
2....................................................................................................................................................................................49
(二 r(2^—E 爭 g...........................................................................................................................................................................51
WVTJ................................................................................................................................................................................51
•(xr + L+ XJ— 0+ X3'XLU 一一 怪 OL...............................................................................................................................51
+ or-................................................................................................................................................................................51
* MiCOL............................................................................................................................................................................51
艸叫)opme....................................................................................................................................................................52
二 e
2n
...................................................................................................................................................................................52
lim (1 一 x) =1, lim 1=1,根据夹逼定理知,.......................................................................................................................56
解对任意自然数 n ,有 肿 sintdt = njjsintdt=2n,............................................................................................................56
(n +1) 兀 x n 兀.............................................................................................................................................................56
IX....................................................................................................................................................................................56
(叮 1 + x)2+(n‘1 + x)2 +…+(M1+x) +1......................................................................................................................56
lim f (r
n
) = f (x
0
) =0,故 f (x) = 0。.................................................................................................................................65
f (x) = lim f (x
2n
)...........................................................................................................................................................67
f(0)...............................................................................................................................................................................67
-
(6X
)......................................................................................................................................................................................71
第三节 数列极限.................................................................................................................................................................74
§ 3.1 数列极限内容网络图....................................................................................................................................................74
§ 3.2 内容提要与释疑解难....................................................................................................................................................75
Ibn,...............................................................................................................................................................................77
(3) ni*= W(b“. bn n>::bn b..........................................................................................................................................79
§ 3.3 解题方法与技巧..........................................................................................................................................................79
(ii ) 当 Ocqc1 时,于呂 > 0 ,要使 q
n
—O£EU q
n
^E= Inq "cl nln qcl (由............................................................................79
ln ;..............................................................................................................................................................................79
In e In w.......................................................................................................................................................................79
ln
lq.......................................................................................................................................................................................79
n...................................................................................................................................................................................81
,于是 Vn -1....................................................................................................................................................................81
:
.n................................................................................................................................................................................81
+…+amjL nf................................................................................................................................................................82
1 1 1.............................................................................................................................................................................82
n n n.............................................................................................................................................................................82
n...................................................................................................................................................................................82
0,..................................................................................................................................................................................82
m :: k,......................................................................................................................................................................82
m 二 k..........................................................................................................................................................................82
m k...............................................................................................................................................................................82
4...................................................................................................................................................................................83
2...................................................................................................................................................................................83
1 1................................................................................................................................................................................83
,求 f(x)的定义域。
x -2
要使函数式子有意义,必须满足
11
1x^2
故所给函数的定义域为 〈x:x・R 且 x=1,x = 2?。