granica twierdzenie o trzech ciagach
szarlotka: | 1 | | 1 | | 1 | |
lim {n →∞) [n( |
| + |
| + ... + |
| |
| n2 + 1 | | n2 + 2 | | n2 + n | |
oblicz granicę
27 lis 13:59
Janek191:
| n | | n | | n | |
bn = |
| + |
| + ... + |
| |
| n2 + 1 | | n2 + 2 | | n2 + n | |
Niech
| n | | n | | n | | n2 | |
an = |
| + |
| + ... + |
| = |
| |
| n2 +n | | n2 +n | | n2 +n | | n2 + n | |
| n | | n | | n | | n2 | |
cn = |
| + |
| + ... + |
| = |
| |
| n2 + 1 | | n2 + 1 | | n2 + 1 | | n2 + 1 | |
Mamy
a
n ≤ b
n ≤ c
n
i
lim a
n = 1 i lim c
n = 1
n→
∞ n→
∞
więc na podstawie tw. o trzech ciągach
lim b
n = 1
n→
∞
27 lis 14:26
szarlotka: dzieki ale moge jeszcze poprosic o rachunki jak to dochodzi do tego ze z n robi sie n2?
27 lis 14:47
Adamm: n2=n*n=n+...+n, n razy
27 lis 14:49