??cKDf
?¥ ???
x2
?
¥K
1.¨?l£
ü/
?
¥K1
,
(5) limn!1(pn+1?pn)
£
ü
n5
jpn+1?pnj = (n+1)?npn+1+pn
? 1pn
?[8" > 0,|N = [ 1"2],5?n > N
Hμ
jpn+1?pnj? 1pn ? "
?K?l?V
U
limn!1(pn+1?pn) = 0
(6) limn!1 10nn!
4
U
10n
n! =
10
1 ¢
10
2 ¢¢¢
10
1 0¢¢¢
10
n
? 10
9
9! ¢
10
n
2¨?l£
ü
(4) limn!1xn = 3?xn =
8>
>><
>>>:
3; n = 3k
3n+1
n ; n = 3k +1(k = 1;2;¢¢¢)
2+ 1+n3?pn+n; n = 3k +2:
1
£
ü?n = 3k;k = 1;2;¢¢¢
H
jxn ?3j = 0
?n = 3k +1;k = 1;2;¢¢¢
H
jxn ?3j = j3n+1n ?3j
? 1n
?n = 3k +2;k = 1;2;¢¢¢
H
jxn ?3j = j2+ 1+n3?pn+n ?3j
? ?2+
pn
3?pn+n
?
pn
?n2 +n; (?n ? 9
H)
? 2pn
8
?n ? 9
H
jxn ?3j? 1n + 2pn ? 4pn
#8" > 0,|N = max9; 16"2,5?n > N
Hμ
jxn ?3j? 4pn < "
?[
limn!1xn = 3
8p/
K
(1) limn!1( 11¢2 + 12¢3 +¢¢¢+ 1n(n+1))
4
U1n(n+1) = 1n ? 1n+1.
2
(2) limn!1( 1n2 + 1(n+1)2 +¢¢¢+ 1(2n)2)
4
U
1
n2 +
1
(n+1)2 +¢¢¢+
1
(2n)2
? 1n2 + 1n2 +¢¢¢+ 1n2
1
n
(5) limn!1(1? 1np2)cosn
4
UK?i b
(8) limn!1[(n+1)fi ?nfi]0 < a < 1
4
Uy10 < a < 1,
?[
(n+1)fi ?nfi = nfi[(1+ 1n)fi ?1]
? nfi[(1+ 1n)?1]
= 1n1?fi
(9) limn!1 12 ¢ 34 ¢¢¢¢¢ 2n?12n
3E1??
2n = (2n?1)+(2n+1)2 ?
p
(2n?1)(2n+1)
?[
1
2 ¢
3
4 ¢¢¢¢¢
2n?1
2n
? 1p1¢3 ¢ 3p3¢4 ¢¢¢¢¢ 2n?1p(2n?1)(2n+1)
? 1p2n+1
?[?
limn!1 1p2n+1 = 0
3
P?
limn!1 12 ¢ 34 ¢¢¢¢¢ 2n?12n = 0
3E2:
xn = 12 ¢ 34 ¢¢¢¢¢ 2n?12n
yn = 23 ¢ 45 ¢¢¢¢¢ 2n2n+1
5^n
xnyn = 12n+1
O
xn ? yn
?[
xn ?pxnyn ?
r 1
2n+1
#?
limn!1 1p2n+1 = 0
P?
limn!1 12 ¢ 34 ¢¢¢¢¢ 2n?12n = 0
16
!limn!1an = a£
ü
(1) limn!1 a1+a2+¢¢¢+ann = a
?ù
?¥I5? ??$
£
ü8" > 0;9N1 2 N;
P¤?n > N1
Hμ
janj < "2
?|?¥N1a1 +a2 +¢¢¢+aN1
^B?%?¥
?yN V[|N > N1,
P
¤?n > N
Hμ
ja1 +a2 +¢¢¢+aN1n j < "2
4
?
^ ?¨????
T¤
ja1 +a2 +¢¢¢+ann j = ja1 +a2 +¢¢¢+aN1n + aN1+1 +aN1+2 +¢¢¢+ann j
? ja1 +a2 +¢¢¢+aN1n j+jaN1+1 +aN1+2 +¢¢¢+ann j
< "2 + (n?N1)
"
2
n
< ":
I5?? ? è?an = (?1)n.
(2)?an > 05limn!1 npa1a2¢¢¢an = a.
4
U ?¨
5¥2
? b
18¨?l£
ü/
?
1íkv
(4) 1+ 12 + 13 +¢¢¢+ 1n.
3?i??
?ni??
?k
P¤2k ? n < 2k+1,
?[
1+ 12 + 13 +¢¢¢+ 1n
= 1+ 12 +(13 + 14)+(15 + 16 + 17 + 18)+¢¢¢
+( 12k?1 +1 + 12k?1 +2 +¢¢¢+ 12k?1 +2k?1)+ 12k +1 +¢¢¢+ 1n
? 1+ 12 +(14 + 14)+(18 + 18 + 18 + 18)+¢¢¢
+( 12k + 12k +¢¢¢+ 12k)
| {z }
2k?1?
= k +12
? lnn2ln2
A?18M > 0,??
T
lnn
2ln2 > M?N?n > 2
2M
5
yN|N = [22M],5?n > M
Hμ
1+ 12 + 13 +¢¢¢+ 1n > M
2
?£8 b
x3f
?¥K
3
!f(x) > 0£
ü?limx!x
0
f(x) = A5limx!x
0
n
pf(x) = npA?
??
?n ? 2.
4
U?A = 0,52
?^£ b/
!A > 0,N
H
j n
p
f(x)? npAj = jf(x)?Aj( npf(x))n?1 +( npf(x))n?2 npA+¢¢¢+( npA)n?1
? jf(x)?Aj( npA)n?1
5p/
f
?3
?
U?¥P·K
(5) f(x) =
8
>>><
>>>
:
2x; x > 0;
0; x = 0;
1+x2; x < 0
x = 0.
4
U5¨?l£
ü
limx!02x = 1
18
!f
?f(x)(0;+1)
?@Z?f(2x) = f(x)Olimx!+1f(x) =
A£
ü
f(x) · A;x 2 (0;+1):
£
ü?i¥x 2 (0;+1)μ
f(x) = f(2x) = f(22x) = ¢¢¢ = f(2nx);8??
?n
6
T
H
7n !1|K'¤
f(x) = limn!1f(2nx) = limx!+1f(x) = A
x4f
?¥ ???
9?f(x)?g(x)?[a;b] ??
k£
ümax(f(x);g(x))
?min(f(x);g(x))?[a;b] ??.
4
U
max(f(x);g(x)) = (f(x)+g(x))+jf(x)?g(x)j2
min(f(x);g(x)) = (f(x)+g(x))?jf(x)?g(x)j2
x5íkl
Díkv
¥1?
3?x ! 0
H/
?
T? ?
?$
(1) o(x2) = o(x)
3? ?.y1
limx!0 o(x
2)
x = limx!0
o(x2)
x2 ¢x = 0
(2) O(x2) = o(x)
3? ?.y1
limx!0 O(x
2)
x = limx!0
O(x2)
x2 ¢x = 0
(3) x¢o(x2) = o(x3)
3? ?.y1
limx!0 x¢o(x
2)
x3 = limx!0
o(x2)
x2 = 0
7
(6) o(x) = O(x2).
3?? ?. è?f(x) = x32,5f(x) = o(x),?f(x) 6= o(x2)
8