Lista 6,
Kierunek: AiR, sem. I, 2008/2009
Granice ci
,
ag´
ow liczbowych
1.
Oblicz granice nast
,
epuj
,
acych ci
,
ag´
ow liczbowych:
a) a
n
=
n
3
+2n
2
+1
n−3n
3
b) b
n
=
(n
20
+2)
3
(n
3
+1)
20
,
c)c
n
=
(n
2
+1)n!+1
(2n+1)(n+1)!
,
d) d
n
=
3
√
8
n+1
+3
2
n
+1
,
e) a
n
=
√
n
3
+1
5
√
n
5
+1+1
,
f) b
n
=
√
n
2
+ 4n + 1 −
√
n
2
+ 2n,
g) c
n
=
p
n + 6
√
n + 1−
√
n,
h) d
n
=
4
√
n
4
+ 16−n,
i) a
n
=
1+3+...+(2n−1)
2+4+...+2n
,
j) b
n
=
1+
1
2
+
1
22
+...+
1
2n
1+
1
3
+
1
32
+...+
1
3n
,
k)
√
4
n
+1
3
√
8
n
+1
,
l) c
n
=
arctg(3n+1)
arctg(2n+1)
,
m) a
n
=
3
√
n
3
+ 3n − n,
n) b
n
=
3
√
n
3
+ 2n
2
− n,
o) c
n
= (−1)
n
· (
2
3
)
n
p) a
n
=
1+
1
2
+
1
22
+...+
1
2n
1+3+...+(2n−1)
,
r) b
n
=
arctgn
arcctgn
.
2. Oblicz granice nast
,
epuj
,
acych ci
,
ag´
ow korzystaj
,
ac z twierdzenia o trzech
ciag
,
ach:
a) a
n
=
n
√
n2
n
+ 1,
b) b
n
=
2
n
sin n
3
n
+1
,
c)c
n
=
2n+(−1)
n
3n+2
,
d) a
n
=
n
q
3
n
+2
n
5
n
+4
n
,
e) b
n
=
n+1
√
2n + 3,
f) c
n
=
n
√
3 + sin n,
g) a
n
=
n+2
√
3
n
+ 4
n+1
,
h) b
n
=
n
√
1 + 5n
2
+ 3n
5
,
i) c
n
=
n
q
1
n
+
2
n
2
+
3
n
3
+
4
n
4
,
j) a
n
=
1
n
2
+1
+
1
n
2
+2
+ . . . +
1
n
2
+n
, k) b
n
=
sin
nπ
2
n
,
l) c
n
=
2
n
+100
3
n
+1
m) a
n
=
2n
2
+sin n!
4n
2
−3 cos n
2
.
3. Oblicz granice nast
,
epuj
,
acych ci
,
ag´
ow korzystaj
,
ac z definicji liczby e:
a)a
n
= (1 +
1
n
)
5n
,
b) b
n
= (1 +
1
n
)
−3n
,
c) c
n
= (1 +
1
n
)
3n−2
,
d) a
n
= (
5n+2
5n+1
)
15n
, e) a
n
= (
n
2
n
2
+1
)
n
2
,
f) a
n
= (
3n
3n+1
)
n
,
g) a
n
= (
3n+1
3n+2
)
6n
,
h) a
n
= (
n
n+1
)
n
,
h) a
n
= (
n+4
n+3
)
5−2n
,
i) a
n
= (
n
2
−1
n
2
)
2n
2
−3
,
j) a
n
= (1 +
(−1)
n
n
)
(−1)
n
n
k) b
n
= (
3n+2
5n+2
)
n
· (
5n+3
3n+1
)
n
.