n2 3n2 2n
n2-2 n+1 n2+4
an = bn = cn =
n2 n n2+3
n 3n-4 2-3n
n n+1 n+4
dn = en = fn =
n+1 n n+3
n0 " N n > n0
an d" bn limn an = " limn bn = "
-"
"
n
an = 3n5 - n6 + 7 bn = (3 + (-1)n)n cn = n!
3n+6n 1 1 1
dn = en = 1 + 2n - 3n fn = 1 + + + ... +
4n+5n 2 3 n
1 1 1 1
+ + ... + e" n " N
n n+1 n+n 2
1
limn an = 0 an > 0 limn an = "
{an}
L
L
{an}
+" -" limn(an - an-1) = 0
L L
q = 1 n " N

1 - qn+1
1 + q + q2 + ... + qn = .
1 - q
1 1 1
1+ + +...+
1 1 1 2
22 2n
" " "
an = + + ... + bn =
n 1+3+5+...+(2n+1)
1 2