matan-1_2
.pdf
! 0 ; o O |
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y
= lim = 1 y→0 ln(1 + y)
E
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(1 + x)α 1 + αx |
x → 0 : |
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lim |
(1 + x)α − 1 |
= lim |
eα ln(1+x) − 1 |
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ln(1 + x) |
= 1 |
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x 0 α ln(1 + x) |
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E
C M 7 , <
#"L " 4 3. f f1 g g1 x → x0
lim |
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(4.3) |
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g(x) |
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x→x0 |
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' & #
C (f f1) (g g1) x → x0: <
f (x) = α(x)f1(x) g(x) = β(x)g1(x)
, x0: , 7 lim α(x) = lim β(x) = 1 5 7: |
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x→x0 |
x→x0 |
, N4 2O # 7 7: , <
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Ox0 : g1(x) = 0
β(x) = 0 ! M
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α(x) |
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, 7 |
lim |
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β(x) |
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L 7 7 , D <
D 7
5 / 9 ! o O
C M D , , < , : D 7 <
7 D E E 7 : 7
LC "5"("'$" 6- C x0 R x0 = ±∞: x0 = ∞ #
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ε >•0δ |
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• ε |
dom |
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x |
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NTO( lim f (x) = |
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x x0 |
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n→∞ n = 0 n→∞ ( n) = ∞); |
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( lim x |
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lim f x |
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! 0 ; o O
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ε >•0δ |
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NTTO( lim f (x) = |
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x x0 |
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lim x |
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+C c'"'$" 6- 5 M <
, % E
C 7 7 (
LC "5"("'$" 6 3 y = f (x)
x → x0: lim f (x) = 0 y = f (x) <
x→x0
! y = g(x) x → x0:
f (x) = α(x)g(x): α(x) Q , 7 x → x0 L <
, M 7 78 f o(g) N, F 7 FO
x → x0 " f o(g) g(x) Q , 7 x → x0:f 7
! g x → x0
C$" 6- x2 o(x) x → 0: x2 = x · x C$" 6 3 x o(x2) x → ∞: x = 1/x · x2
, E D 7 x
LC "5"("'$" 6 2 / 7 : , y = f (x)
! y = g(x) x → x0 N <
•
, f = O(g): , F E gFO: Ox0 c > 0
•
x Ox0 (|f (x)| ≤ c|g(x)|)
C$" 6 2 1/x = O(1/x2) x → 0: |1/x| ≤ 1/x2
|x| ≤ 1
C$" 6 4 1/x2 = O(1/x) x → ∞: 1/x2 ≤ |1/x|
|x| ≥ 1
+ 7 o O
#"L " 6- c R \ {0} x → x0
NTO o1(cf ) = co2(f ) = o(f ) O1(cf ) = cO2(f ) = O(f )=
NTTO o1(f ) + o2(f ) = o(f ), O1(f ) + O2(f ) = O(f ) o(f ) + O1(f ) = O(f )=
NTTTO o1(o2(f )) = o(f ) o1(O(f )) = o(f ), O(o1(f )) = o(f ) O1(O2(f )) =
O(f );
( ( 0 . .
&
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NThO g(x) = 0 x Ox0 |
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NTO o1(cf ) = α(x)(c ·f (x)) = cα(x) ·f (x) = (c ·α(x)) ·f (x) = o(f ):
α(x): c · α(x) Q , 7 x → x0
! 7 6- < , +C c'"'$
#"L " 6 3 N M O f g
x → x0) (f (x) = g(x) + o(g) x → x0O |
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C f |
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lim α(x) = 1 # |
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f (x) |
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lim β(x) = 0 |
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# 7 |
C f (x) = |
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g(x)+α(x)g(x): lim α(x) = 0 : f (x) = (1+α(x))g(x) =
x→x0
β(x)g(x): lim β(x) = 1
x→x0
!7 7 4- 7 <
8
sin x = x + o(x), |
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ex − 1 = x + o(x), |
VXx = x + o(x), |
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x → 0 |
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ln(1 + x) = x + o(x), |
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arcsin x = x + o(x), |
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(1 + x)α = 1 + αx + o(x). |
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5 7 0 '
LC "5"("'$" 0- $ (x0, x0 + δ) N(x0 − δ, x0)O
N O δ! , x0
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Ox0 O 5 7 7 |
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Ox0 = {x R : x0 < x < x0 + δ}, |
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LC "5"("'$" 0 3 C x0 R
! 1 ,
y = f (x) x → x0
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ε > 0 |
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δ δ > 0 |
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1 y = f (x) x |
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7 , 7 : 7 7 ∞ ±∞
+C c'"'$" 0- 5 M
% E D
+C c'"'$" 0 3 7 7 <
7 , 7 7
7
+C c'"'$" 0 2 7 % < E ,
,
C$" 0- : , y = WXYx ,<
7 L M
, 5 :
7 7 : , xn → 0 n → ∞:
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lim WXYx = lim WXYxn = 1, |
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lim WXYx = lim WXYx |
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C$" 0 3 5 D |
x R \ Q |
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x Q, |
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! 1 , |
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7 : , 5 <
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lim D |
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R |
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C M 7 |
lim |
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x0+ D |
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lim |
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) " '$" " x0 = ∞: 7 : , |
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lim f (x) = |
lim |
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f (x), |
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f (x) = |
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x→x0− |
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#"L " 0- N O |
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x0 R x0 = ∞ y0 R y0 = ∞, ±∞# ) |
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lim f (x) = y |
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! 7 7 C {xn} dom f \
{x0} 7 {xn} = {xn} {xn}:
xn > x0: xn < x0 L, :
( lim x |
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= x |
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n→∞ |
n |
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L 7
5 7 E 7
<
L E
: D D <
E
' 7 7: , y = f (x)
!' N !'O 7 7 X R:
x , x X: x < x 7 7 f (x ) ≤ f (x ) Nf (x ) ≥ f (x )O
7 <
D 7 D
#"L " 0 3 y = f (x)
(a, b)# ) |
lim f (x) |
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lim f (x) ' ! |
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x0 (a, b)# A x0 (a, b) |
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sup f (x) = |
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lim f (x) |
≤ |
f (x |
) |
≤ x |
lim f (x) = |
inf f (x). |
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a<x<x0 |
x |
→ |
x0 |
− |
0 |
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x0+ |
x0<x<b |
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! 3 ; ' ( &
" a < x0 < x0 < b
f (x |
+ 0) = |
lim f (x) |
lim |
f (x) = f (x |
− |
0). |
0 |
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x→x0+ |
≤ x→x0 − |
0 |
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C 7 , {f (x) : a < x < x0} <
, D , 7 f (x0) M 7 7 , D
s(x0) L, : , s(x0) ≤ f (x0) C 7: , s(x0) = f (x0 − 0) C 7 ε > 0 7 δ > 0 : , a < x0 − δ 7 7 s(x0) − ε < f (x0 − δ) ≤ s(x0) C f 7
:
f (x0 − δ) ≤ f (x) ≤ s(x0) x0 − δ < x < x0.
• δ
5 7 7 : |f (x)−s(x0)| < ε x l Ox0 , lim f (x) =
x→x0−
s(x0)
! , ,
5 :
sup f (x) = f (x0 − 0) ≤ f (x0 + 0) =
a<x<x0
7 7 a < x0 < x0 < b
f (x0 + 0) = inf f (x) = |
inf |
x0<x<b |
x0<x<x0 |
inf f (x)
x0<x<b
f (x).
f (x0 − 0) = sup f (x) = sup f (x).
a<x<x0 x0<x<x0
$ D D , 7 7
+C c'"'$" 0 4 7 <
7 0 3 7 D
5 D ! # ' ? > ; A
> ;
C x0 dom f ' 7 7: , y = f (x)
x0: lim f (x) = f (x0) N5 7 7 :
x→x0
lim f |
x |
) = |
f |
lim x |
) |
x |
0 |
dom |
f O |
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! 3 ; ' ( &
! 7 0 3 7 7 M LC "5"("'$" 1- C x0 dom f y = f (x) <
x0: lim f (x) = |
lim f (x) = |
x→x0− |
x→x0+ |
f (x0) |
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LC "5"("'$" 1 3 "
, x0 dom f : 7 7 : , f
x0: , f x0
% E : 5 D y = D(x) <
, ! 7 7
M ,
C$" 1- 7 y = R(x):
R(x) = |
1 , |
x = m |
7 , |
0, x R \ Q− |
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7: , : , 7 D D , : <
D N 7 : 7 : , x0: x0 QO
•
E N # 7 7: , x0 Ox0 |R(x)| < 1/N:
lim R(x) = 0
x→x0
(L% ( ' " !L& #! D 8
NTO , x0 R y = f (x)
, ;
NTTO y = f (x) y = g(x) , x0: D 77 (f + g)(x): (f · g)(x) , (f /g)(x) N
, g(x0) = 0O , x0 ;
NTTTO y = g(x) z = f (y) Q : , 7 im g dom f : g , x0: f , y0 = g(x0);
D 7 , x0
5 D <
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LC "5"("'$" 1 2 : , <
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LC "5"("'$" 1 4 # , x0 dom f ,
: |
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f (x0) # , |
x0 dom f , : <
: f (x0 − 0) = f (x0 + 0) + 7
: <
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y = |WXYx| 7 , 7
+ 7 7 7 <
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5 D , 7
5 8 # ' ? > ;
#"L " =- N/ <% E 7 , 7 , O
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5 7 [a, b] 7 " ,
: D D , D <
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7< E 7 , c (a, b): f (c) = 0: <
, 7 {In} D : D
7 C % E < % !c R (c Inn N) 7 7 {xn} {xn} <
In L, : , lim x |
= lim x = c: , 7 f (x |
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n→∞ n |
n→∞ n |
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n |
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f (x ) > 0 L 7 7 |
lim f (x |
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n |
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n |
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("5 #!$" =- . y = g(x)
I a, b I g(a) = A = B = g(b)
! C ' A B c R
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7 7 f (x) = g(x) − C ' [a, b] f (a) · f (b) = (A −C) ·(B −C) < 0 % 7 : f C[a, b]
) , : c (a, b) (0 = f (c) = g(c) − C)
#"L " = 3 N! E 7 7 7 , O C
# &
#
C f C[a, b] # x (a, b) Ox : , Ox ∩ [a, b]
f , D Ox <
[a, b] 7 :
/ < ( 7 , {Ox1 , . . . , Oxn }:
: 7 D mk ≤ f (x) ≤ Mk: k = 1, . . . , n ) , : x [a, b]
min{m1, . . . , mn} ≤ f (x) ≤ max{M1, . . . , Mn},
f , [a, b] C s = sup f (x)
x [a,b]
C 7: , f (x) < s x [a, b] # [a, b]
s − f (x) = 0 x [a, b]: D 7 7 , :
# 1/(s − f (x)) <
[a, b]: , C ,
$: xs [a, b] (f (xs) = s)
, : i = infx [a,b] f (x) 7
! 4 < ' ( &
f (x) − i: 7: , , xi [a, b] (f (xi) = i) LC "5"("'$" =- y = f (x)
X R:
ε > 0 δ > 0 x , x X (|x − x | < δ |f (x ) − f (x )| < ε).
L 7 7
NTO " 7 7 :
M 7 7 5 : ,
, : 7 x = x0:
x = x: , 7 ε > 0 δ > 0 x X (|x − x0| < δ
|f (x) − f (x0)| < ε) := ( lim f (x) = f (x0)) Q
x→x0
% E
NTTO $ : : 7
C$" =- y = sin(1/x) (0, 1)
7 M 7 D L |
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7
C 7 <
: , : <
, ! % E 7 78 y = f (x) X R x0 X ( lim f (x) = f (x0))
x0 X ε > 0 δ > 0 x X (0 < |x−x0| < δ |f (x)−f (x0)| < ε)
) , δ > 0 7 , x0 Xε > 0: M 7 7 ε > 0 7 7 ,
, ! , 7
7 δ > 0 , ε > 0 : ,
D x0 X |x−x0| < δ x X |f (x)−f (x0)| < ε
" y = f (x) , : 7 :
, x R: 7 <
M : 5 :
7 δ > 0 δ< (x, x + δ) , x ,
x , x : , |x − x | < δ: |f (x ) − f (x )| > 1 #
