.
f(x) g(x), x→R ( ) . ϵ ; f(x) ≤ g(x). limx→a f(x) = A, limx→a g(x) = B ≤.
.
{Xn}, ϵ , Xn ≠ , Xn→. f(Xn)→A, g(Xn)→B. n f(Xn)≤ g(Xn). , ≤.
15.
.
:
.
. 1) : ; 2) : (a+b)n=an nan-1b+n(n-1)an-2b2+(n(n-1)(n-2)/23) an-3b3+(n(n-1)(n-2)(n-3)/234) an-4b4 +
:
Xn=(1+1/n)n, n=1,2,3,4,
: 1=2; 2=2,25; 3=2,37; 4=2,44. {n} .
0 2 2,25 2,37 2,44
xn≥2→ .
, . .
=1, b=1 Xn = 1-n 1/n + (n(n-1)/2) (1/n)2 + (n(n-1)(n-2)/23) (1/n)3
Xn = 2+1/2 (1-1/n) + 1/23 + 1/234 (1-1/n) (1-2/n) (1-3/n) +
(n 1)/n = n/n 1/n = 1 1/n ((n 1)(n 2))/(n n) = (1 1/n)(1 2/n) → < 1.
: Xn<2+1/2+1/23+1/234
2 : Xn < 2 + 1/2 + 1/22 + 1/222 b1=1/2 q=1/2 . S = b1/1-q
, .
16.
. .
( ) , , , .
, . ( ) ( ).
f(x), 0, 0, , ..
lim f(x) = f(X0) .
17.
.. .. . , , , .. .
y=f(x) .. →0, lim f(x)=0. y=f(x) .. →0, lim f(x)=∞.
y=f(x) : →0, . , →0.
|
|
{f(x) = A+α(x), lim α(x)=0}.
. - . |f(x)-A|=α(x). limα(x)=0, α() →0.
: f(x) A = α(x); limα(x)=0, f(x) = A + α(x), α() .
18.