Viša tehnička škola Doboj
Vježbe Prof.Vesna Mišić
Doboj 2003 1
Matematika
Funkcija - definicija 2
Definicija : Funkcija je preslikavanje skupa A u skup B pomoću koga svakom elementu skupa A pridružujemo tačno jedan element skupa B. preslikava f : A → B
Domen ? f( x) 1. y = g( x) 2. y =
f
A x
D : g( x) ≠ 0
f( x)
f
D : f( x) ≥ 0
B y
−1
Domen (područje definisanosti), Kodomen (skup vrijednosti ).
3. y = log f ( x ) D : f ( x ) > 0 4. y = arcsin x D : − 1 ≤ x ≤ 1
1 y=sinx 0 -1
π
2π
y=arcsinx
Inverzne funkcije. f : A→B f : x→B x 0 30 si nx
° 0
° 1 2
x
0
arcsinx
0
3
f
−1
:B→ A
f
−1
:y→x
45° 60° 90 ° 2 3 1 2
1 80° 0
2 70° -1
360° 0
2 1 2 π 6
2 2 π 4
3 2 π 3
1
0
-1
0
π 2
π
3π 2
2π
Funkcija f : A → B je : 1. Injektivna (1-1) ako f ( a ) = f ( b ) ⇒ a = b . 2. Sirjektivna (na) cio skup b ako je f ( A ) = B . 3. Bijektivna (ako je injektivna i sirjektivna). 4. Parna ako je f ( − x ) = f ( x ) za svako x iz A . 5. Neparna ako je f ( − x ) = − f ( x ) za svako x iz A ( ∀x ∈ A) , (simetrična u odnosu na koordinatni početak) . 6. Periodična s periodom ω, ako vrijedi f ( x +ω ) = f ( x ) ( ∀x ∈ A) . 7. Rastuća x1 < x 2 ⇒ f ( x1 ) < f ( x2 ) ( ∀x1 , x 2 ∈ A) . 8. Opadajuća x1 < x 2 ⇒ f ( x1 ) > f ( x2 ) ( ∀x1 , x 2 ∈ A) . 9. Ograničena m ≤ f ( x ) ≤ M ( ∀x ∈ A) , ( m < ∞, M < ∞ ) . 1. a b
1 4 2 5
c
3
Injektivna, ali nije sirjektivna 2. A
1
B 0
2
Sirjektivna ali nije, injektivna, f
3.
2 4
1 2
6 8 10
3 4 5
Bijektivna (injektivna i sirjektivna) 4. Parna
y=cosx 0 4
y=x2
5.
y=x
y=x3
6. y=sinx
7.
f ( x2 )
) f( ′ ) x f(
x2′ 1
x1 x2 a
Domen. 5
f ( x1 )
x1′ x2 ′
b
1. y = sin ln( 2 x − 3)
x x −1 + x2 − 4 2 x+3 ( x − 4) + 4 − 3 x − x 2 3. y = ln x+2
2. y = 2 sin + ln
4. y = sin π ( x − 1) + 4 − x 2 1. D : 2 x − 3 > 0 ⇒ x >
3 2
x 2
2. 2 sin = 0 ∀x ∈ R x −1 >0 x + 3 = 0 ∧ x −1 > 0 x+3 x = −3 ∧ x > 1 -∞
-3
1
∞
x
+
x-1 x+3 x −1 x+3
- 0 + 0 + + +
I1 D : x ∈ ( − ∞ ,− 3) ∪ ( 1,+∞ ) x2 − 4 ≥ 0 ( x − 2)( x + 2) ≥ 0 x1 = 2 ∧ x 2 = −2
-∞
x+2 x2-4
I 2 D : x ∈ ( - ∞ ,-2] ∪ [ 2,+∞ )
6
2
x x-2
( D : I1 ∩ I 2 )
-2
+
- 0 + 0 + + +
∞
-3
-2
1
2
D : x ∈ ( − ∞,−3) ∪ [ 2,+∞ ) x−4 x−4 > 0 ∧ ln ≥0 x+2 x+2
3. D :
x−4=0 x=4 x+2=0 x = −2
x−4− x−2 ≥0 x+2 −6 ≥0 x+2 x+2<0 I 2 : x < −2 D : x ∈ ( − ∞ , −2 )
x−4 ≥1 x+2 x−4 −1 ≥ 0 x+2
-∞
-2
4
∞
x
-
x-4
+
x+2 x−4 x+2
- 0 + 0 + + +
I1 D : x ∈ ( - ∞ ,-2) ∪ ( 4,+∞ ) 4 − 3x − x 2 ≥ 0 3 ± 9 + 16 x1, 2 = −2 x1 = 1
− x 2 − 3x + 4 ≥ 0
x 2 = −4
I 3 : D : x ∈ ( − 4,1)
D : x ∈ [ − 4,− 2) -4
7
-2
1
4
4. y = sin π ( x − 1) + 4 − x 2 sin π ( x − 1) ≥ 0 0 ≤ π ( x − 1) ≤ π 0 ≤ x −1 ≤ 1
x ≥ 1 ∧ x ≤ 2 I1′ − 4π ≤ π ( x − 1) ≤ −3π − 4 ≤ x − 1 ≤ −3 − 3 ≤ x ≤ −2
-3
− 2π ≤ π ( x − 1) ≤ −π / : π − 2 ≤ x − 1 ≤ −1 x ≥ −1 ∧ x ≤ 0 I ″ 1
/ :π
-2
D : x ∈ { 2} ∪ [ − 1,0] ∪ [1,2] 5. y = x − 3 − x x−3 = 0
-1
0
x ∈ ( − ∞ ,0 )
I1
1
y = −( x − 3) − x y = −2 x + 3
y = −( x − 3) + x y=3
x =0 I1
I2
( 3,+∞ )
y = x −3− x y = −3
x y
0
2
3
-1
I3
0 I3
2
x ∈ [ 0,3)
I2
y = x−3 − x
x =3
4 − x2 ≥ 0 ( 2 + x )( 2 − x ) ≥ 0 I 2 x ∈ [ − 2,2]
3 y=3 3 y=-2x+3 3 y=-3 -3
1) Da li je funkcija injektivna? y = 3x + 5
5
−
8
5 3
0
Sirjektivna
2) Naći nule funkcije
(
y = ln x 2 − 3
)
D : x2 − 3 > 0 y=0 ln 1 = 0
(
) (
D : x ∈ − ∞ ,− 3 ∪
3 ,+∞
)
0 = 1 f = 0 ⇒ x2 − 3 = 1 x2 = 4 x1, 2 = ±2
-2
y>0
x ∈ ( − ∞ ,− 2) ∪ ( 2,+∞ )
y<0
x ∈ − 2,− 3 ∪
(
) (
3 ,2
− 3
3
2
)
8. Koja je funkcija parna, a koja je neparna? y = x 3 + 3x + 1 funkcija u tački − x y ( − x ) = ( − x ) 3 + 3 ⋅ ( − x ) + 1 = − x 3 − 3 x + 1 nije ni parna ni neparna. x + − x 2 ( −x) + −( − x ) x + − x y( − x ) = = = y ( x ) Funkcija je parna. 2 2 x 9. y = ln Inverzna funkcija. 4 y y x = ln x = 4x = y 4 4 funkcija siječe osu y u broju 4. 1 10. y = 1 − x − 1 y( x ) =
I1 D : x − 1 = 0 9
x =1
x ∈ ( − ∞,1)
1 1 + ( x − 1) 1 y= D : x ∈ R /{ 0} x y=
I2
y
x ∈ [1,+∞ )
x
1 1 − ( x − 1) 1 y= 2− x D: x ≠ 2 y=
x=0
1 D: x ≠3 11. y = x−3 x > 0 funkcija je pozitivna x < 0 funkcija je negativna
y=−
x=1
x=2
1 3
x=3
12. y =
1 2−x
D: x ≠ 2
x > 0 funkcija je negativna x < 0 funkcija je pozitivna 1 x = 0 siječe y – osu u y = 2
y=
1 2
x=2
Granične vrijednosti - ( limesi ) 1 an = - niz n
0
1 4
1 1 3 2
1
(a-ε, a+ε) - epsilon okoline tačke a 10
a-ε
(
a
)
a+ε
ε okoline tačke a
1
=0 lim n→∞ n
a 0 n k + a1n k −1 + ⋅ ⋅ ⋅ + a n ⋅ n 0
lim k k −1 + ⋅⋅⋅ + b n →∞ b n + b n
1 =∞ lim n →0 n
0
1
n
⋅n
0
=
a0 b0
( k ∈ N )( n ≠ 0 ∧ k ≠ 0)
7 6n − 7 6n − 7 / : n n =6=2 = lim = lim 13. lim 3 n →∞ 3n + 2 n→∞ 3n + 2 / : n n →∞ 3 + 2 n n 1 1 1 1 ⋅ n − 1 − 1 1− n 1 1 3 1 1 = 3 = 3 3 14. lim + 2 + ⋅ ⋅ ⋅ + n = lim ⋅ 1 lim lim 2 3 3 2 n →∞ 3 3 n →∞ n →∞ − 1 n →∞ − 3 3 6−
= 1 2
15. 2 2n +4 (1 + 2 n ) 1 + 2 + 3 + ⋅ ⋅ ⋅ + 2n 2 n ( 1 + 2 n ) 2 + 4 n n n 2 = = = : = =4 lim lim lim lim n 1 1+ 2 + ⋅⋅⋅ + n n( 1 + n ) 1 + n n lim n →∞ n →∞ n → ∞ n → ∞ n → ∞ (1 + n ) +1 2 n x 2 − 5 12 − 5 4 = =− 16. lim 1+ 2 3 x →1 x + 2
17.
x 2 + 6 x − 16 ( x − 2)( x + 8) = x+8 2+8 = lim = =2 lim lim 2 2+3 x + x−6 x →2 x →2 ( x − 2 )( x + 3) x→2 x + 3
18.
(
)
2 3 ⋅ (1 + x ) − 2 ⋅ 1 + x + x 2 3 + 3x − 2 − 2 x − 2 x 2 3 − = = = lim lim lim 3 2 1 − x 2 x→1 (1 − x ) ⋅ (1 + x ) ⋅ 1 + x + x 2 x →1 1 − x x →1 (1 − x ) ⋅ (1 + x ) ⋅ 1 + x + x
(
)
(
)
1 + x − 2x ( − 2 x − 1)( x − 1) − ( − 2 x − 1) = lim = lim = 2 2 2 x →1 (1 − x ) ⋅ (1 + x ) ⋅ 1 + x + x x →1 − (1 − x ) ⋅ (1 + x ) ⋅ 1 + x + x x →1 (1 + x ) ⋅ 1 + x + x 2x + 1 2 +1 1 = lim = = 2 2⋅3 2 x →1 (1 + x ) ⋅ 1 + x + x 2
= lim
(
(
)
(
)
)
x2 x = −1 - vertikalna asimptota x +1 y = 0 ⇒ x = 0 nula funkcije je u nuli y 2 x2 y x2 x2 1 : 2 = lim =1 kosa asimptota k = lim = lim x + 1 = lim 2 x x →∞ x x →∞ x →∞ x + x x x →∞ 1 + 1 x 2 2 2 x x − x −x x −x = lim n = lim ( y − k ⋅ x ) = lim − x = lim = −1 x + 1 x →∞ x + 1 x →∞ x →∞ x + 1 x →∞ 0 -1
19. y =
x y= x+1
11
(
)
x2 − 4 20. y = 2 x −1
y( − x ) =
( − x) 2 − 4 = ( − x) 2 − 1
x2 − 4 = y funkcija je parna x2 −1
x 2 − 4 = 0 ⇒ x1, 2 = ±2 nule funkcije x 2 − 1 = 0 ⇒ x = ±1 vertikalne asimptote x2 − 4 1− 4 − 3 = = =∞ lim 2 1−1 0 x →1 x − 1 x 2 − 4 ( − 1) 2 − 4 − 3 = = =∞ lim 2 ( − 1) 2 − 1 0 x → −1 x − 1
vertikalne asimptote
4 1− 2 x2 − 4 x2 − 4 / : x2 x =1 = lim 2 = lim lim 2 2 1 x →+∞ x − 1 x →+∞ x − 1 / : x x →+∞ 1 − x2
y x =0⇒ y =
0−4 =4 0 −1
(0,4)
y=1 -1 0 1 2 −x x -2 x y( − x ) = = − ( − x ) 2 − 9 x 2 − 9 funkcija je neparna x2 − 9 D : x ≠ ±3 x = 0 nula funkcije
21. y =
12
x
x
0
y = lim 2 = = 0 horizontalna asimptota je x – osa lim 1 x →∞ x →∞ x − 9 x
3
3
= lim = =∞ lim 2 0 x →3 x − 9 x →3 9 − 9
vertikalne asimptote
x −3 −3 = lim = =∞ lim 2 2 0 x → −3 x − 9 x → −3 ( − 3) − 9 y
y=
-4
-3
-2
-1
0
1
2
3
4
x x2 − 9
x
x=3
x=-3
OMM X ~ OAB 5 2 proporcionalnost = ∞; =0 0 ∞ stranica 0 ∞ ∞ 0 ; ; ; ; neodređeni oblici MM X AB 0 ∞ 0 ∞ = B OM X OA 1 1− 3 x 1M− 3 x 1 1 = lim − = −3 =− 22. lim x − 1 = lim 3 3 3 2 2 3 1 + 1 +1 x →1 x →1 − 1 − 3 x x + 3 x + 1 sinxα→1 ABx + 3 x + 1 = ⇒ AB = tgα α cos α 1 4 + x + 2 ⋅ ( 4 + x ) 2 + 3 ( 4 + x ) ⋅ 4 + 3 16 4+ x −2 0 4 +Mxx − 2A(1,0) = = lim 3 ⋅ lim 3 3 3 2 4+ x − 4 4+ x − 4 x →0 x →0 4 + x + 2 ⋅ ( 4 + x ) + 3 ( 4 + x ) ⋅ 4 + 3 16 23. ( 4 + x − 4) ⋅ ( 4 + x ) 2 + 3 ( 4 + x ) ⋅ 4 + 3 16 3 16 + 3 16 + 3 16 3 ⋅ 23 2 33 2 = lim = POAM= < Pisj.OAM < POAB = 2+2 4 2 ( 4 + x − 4) ⋅ 4 + x + 2 x →0 1 ⋅ sin x x ⋅ 1 1 ⋅ tgx sin x < < /: B 2 2 2 2 M x 1 sin x 1< < = 1 24. lim x sin x cos x x →0 sin x cos x < <1 Mx A Dokaz : 0 x x → 0 ⇒ cos x = 1 sin x 1< <1 x 13 sin x =1 lim x x →0
(
)(
(
( (
)
)
) )
sin ( α + β ) = sin α cos β + cos α sin β sin ( α − β ) = sin α cos β − cos α sin β sin ( α + β ) − sin ( α − β ) = 2 sin α cos β α+β = x α+β = x (+) (-) α −β = y α −β = y 2α = x + y 2β = x − y x+ y x− y α= β= 2 2 sin x − sin y = 2 cos
14
x+ y x− y ⋅ sin 2 2
25.
(
)(
)
sin 4 x − sin 4 a sin 2 x − sin 2 a ⋅ sin 2 x + sin 2 a = lim = lim x−a x−a x→a x→a = lim
( sin x − sin a )( sin x + sin a ) ⋅ (sin 2 x + sin 2 a ) =
x−a x+a x−a 2 ⋅ cos ⋅ sin ⋅ ( sin x + sin a ) ⋅ sin 2 x + sin 2 a 2 2 = lim = x−a x →a x+a x−a cos ⋅ sin ⋅ ( sin x + sin a ) ⋅ sin 2 x + sin 2 a 2 2 = lim = cos a ⋅ 2 sin a ⋅ 2 sin 2 a = 4 ⋅ sin 3 a ⋅ cos a x − a x →a 2 0 ∞ 1∞;0 ∞; ∞0 ; ; Neodređeno 0 ∞ x →a
(
)
(
x
1 1 + = lim x x →∞ ln(1 + x ) =1 lim x x →0
1
(1 + x ) x lim x→0
)
= ≈ 2,71828
a x −1 = ln a lim x x →0
x − 1 =1 lim x x →0
lim x →0
(1 + x ) a − 1 = a x
26. x
x +1 −2 ⋅ ⋅x x +1
x
− 2 −2 x −1 x +1− 2 = lim = lim 1 + lim x + 1 x →∞ x + 1 x →∞ x + 1 x →∞ =
− 2x / : x
= lim lim x →∞ x + 1 / : x x →∞
x + 1 27. lim x →∞ x
28.
x2
(1 + sin x ) lim x →0
−2 1 = −2 = − 2 = 2 1 1+ x
1 = lim 1 + x x →∞ 1 x
=
x⋅ x
= lim x = ∞ = ∞ x →∞
1
1 x x = lim 1 + sin x ⋅ = lim (1 + x ) x = sin x x →0 x →0
29. 1
( cos x ) x lim x →0 =
lim x →0
2
1
= lim (1 + cos x − 1) cos x −1⋅
cos x −1 x2
=
x →0
cos x − 1 − (1 − cos x ) = lim = − lim 2 x x2 x →0 x →0
2 sin 2 x2
x x 1 sin 2 2 =− 2 = − 1 = − 2 = 1 lim 2 x →0 2 ⋅ x ⋅ x 2 2
II. način sin 2
15
x 1 − cos x = 2 2
2 sin 2
x = 1 − cos x 2
cos x = 1 − 2 sin 2
x 2
1
1
2 2 xx 2 x − 2 sin 2 x 1 − 2 sin = 1 + − 2 sin 2 lim lim 2 2 x →0 x →0
⋅
− 2 sin 2 x2
x 2
−
=
1 2
1
=
1
1 x − 1 x − 1 = x ⋅ =1 30. lim lim 1 x ←∞ x → ∞ x
Odrediti asimptote funkcija : 1 ⇒ x D: x ≠ 0
31. y = x −
lim x →0
2
y=
x −1 = lim x x →0
y = kx + n
x2 −1 x 1 x 2 = 1 = ∞ vertikalna asimptota je x=0 tj. y – osa. 1 ∞ x
1−
1 x2 −1 1− 2 2 x −1 x =1 k = lim x = lim 2 = lim x 1 x x →∞ x →∞ x →∞ 1 − x2 −1 x2 −1− x2 n = lim − x = lim = x =0 x x 1 x →∞ x →∞ y = x kosa asimptota
nule funkcije x 2 − 1 = 0 x2 = 1 x1, 2 = ±1 y y=x
y = x−
1 x
x
x=0 D: x+2≠ 0 x−2 32. y = vertikalna asimptota x = −2 x+2 x ≠ −2 x − 2 = 0 ⇒ x = 2 nula funkcije
16
2 x−2/:x x =1 = lim lim x →∞ x + 2 / : x x →∞ 1 + 2 x 1−
y = 1 horizontalna asimptota
Znak -∞
-2
x-2
-
x+2 f(x)
2
+
0
+
+∞
0
+ +
-
+
y=1 -2
-1
0
1
2
y=
(0,-1)
33. y =
x
x−2 x+2
D : x + 1 ≠ 0 x ≠ −1
( x + 1) 2 x
−1
x
1
= lim 2 = lim = − = ∞ lim 2 0 x →−1 ( x + 1) x → −1 x + 2 x + 1 x → −1 1 − 2 + 1
vertikalna asimptota
1 x 0 x = = = 0 horizontalna asimptota je y = 0 x- osa lim lim 2 1 x →∞ x + 2 x + 1 x →∞ 1 + 2 + 1 x x2 y>0 x>0 znak y < 0 x < 0 y′ =
x 2 + 2 x + 1 − x ⋅ ( 2 x + 2)
y ( 1) =
17
( x + 1)
1
(1 + 1) 2
=
4
=
x 2 + 2x + 1 − 2x 2 − 2x
( x + 1)
4
=
− x2 +1
( x + 1)
4
=
1 1 1, funkcija ima maksimum u tački T 4 4
(1 + x )(1 − x ) = 1 − x ( x + 1) 4 ( x + 1) 3
y
y=
x
( x +1) 2
1 4 -1
0
1
y=0
x
x=-1
34. y = x − x 2 + x − 2
D : x 2 + x − 2 ≥ 0 ⇒ x ∈ ( − ∞,−2] ∪ [1,+∞ )
2 lim x − x + x − 2 = lim
(x −
)(
x2 + x − 2 ⋅ x + x2 + x − 2
x + x2 + x − 2 2 −1+ −x+2 1 x = lim = lim =− 2 2 1 2 x →∞ x + x + x − 2 x →∞ 1+ 1+ − 2 x x x →∞
x →∞
) = lim x x →∞
2
− x2 − x + 2
x + x2 + x − 2
y = 0 x − x2 + x − 2 = 0 x = x2 + x − 2 /2
x = 2 nula funkcije
x2 = x2 + x − 2
y
y = x − x2 + x − 2 nema funkcije -2
-1
(-2,-2)
18
0
x 1
2
y=−
1 2
=
x2 +1 x2 − 4 D : x2 − 4 ≠ 0
35. y =
x1, 2 ≠ ±2 x ∈ ( − ∞,−2 ) ∪ ( − 2,2) ∪ ( 2,+∞ )
x 2 + 1 = 0 nema nula ( − 2) 2 + 1 = 5 = ∞ x2 +1 = lim lim 2 2 0 x → −2 x − 4 x → −2 ( − 2 ) − 4
vertikalne asimptote x = −2 ∧ x = 2 x2 +1 22 + 1 5 = lim 2 = =∞ lim 2 0 x →2 x − 4 x →2 2 − 4 1 1+ 2 2 x +1 x =1 = lim horizontalna asimptota y = 1 lim 2 x →∞ x − 4 x →∞ 1 − 4 x2 Znak -∞
-2
x2 +1
+
x−2
-
x+2
-
y
(
)
(
0
) = 2x
2x ⋅ x 2 − 4 − 2x ⋅ x 2 + 1
Znak y ′
(x
2
−4
)
2
3
(x
-10x
x 4 − 8 x 2 + 16
19
x2 +1 0 +1 1 = =− 2 4 x −4 0−4
2
+ +
0
+
+
-
+
− 8x − 2x 3 − 2 x
-
x = 0 y( 0) =
+∞
+
+
Prvi izvod funkcije y′ =
2
−4
)
2
-2
− 10 x x 4 − 8 x 2 + 16
=
0
2
+
+
+
-
-
+
+
+
+
+
+
-
-
x−4 2 =y x+1
2
y
y=1 x -2
-1
0
1
2
T
ln x + 2 ln x D : ln x ≠ 0 ⇒ x > 1
x= -2
x=2
36. y =
1 ln x + 2 y = lim = lim x = 1 Horizontalna asimptota y =1 lim ln x x →∞ x →∞ x →∞ 1 x ln x + 2 0 + 2 2 y = lim = = = ∞ Vertikalna asimptota je x=1 lim ln x 0 0 x →1 x →1 1 ln x + 2 y = lim = lim x = 1 lim ln x x →0 x →0 x →0 1 x y = 0 ln x + 2 = 0 ln x = −2 x = − 2 1 x= 2
Znak funkcije
20
-∞
1
ln x + 2
-
ln x
-
-
y
+
-
0
+∞
+
+
0
+ +
( ,3)
3
y=
ln x + 2 ln x
( 0,1) y=1
1 2 ,0
1
x
x=1
Naći nule funkcija ? x3 − 8 x3 + 8 D : x3 + 8 ≠ 0
37. y =
( x + 2) ( x 2 − 2 x + 4 ) ≠ 0
x+2≠0 ∧ x ≠ −2
x 2 − 2x + 4 ≠ 0
( x − 2) ( x 2 + 2 x + 4) = 0 x=2
Nula funkcije je x = 2 x 4 − 17 x 2 + 16 x2 + 2 D : x2 + 2 ≠ 0
38. y =
(∀
x ∈ R)
x2 = t t 2 − 17t + 16 = 0
t1 = 1 t 2 = 16
x1, 2 = ±1
∧
39. y = log( x − 1)
x −1 > 0 x >1 D: log( x − 1) = 0 x −1 = 1
21
⇒
x2 = 1
x3, 4 = ±4
∧ x 2 = 16 y
y = log( x − 1)
x ∈ (1,+∞ ) x = 2 nula funkcije
x 0
1
2
1 − ln x x2 D: x >0 1 − ln x = 0 ln x = 1
40. y =
y
x ∈ ( 0,+∞ ) x = nula funkcije y =
1 − ln x x2
y = 1− ln x 41. y = tgx − 3
tgx − 3 = 0 tgx = 3 π x = + kπ nula funkcije 3 y
−π
−
2π 3
π − 2
0
42. Izračunati
f( x) + f 1
f 1 = log 6
1 9 + 3 log 3 x x
x
x
π π 3 2
π 4π
3
3π 2
x
2π
, ako je dat izraz f ( x ) = log 6 x + 3 log3 9 x ?
f 1 = − log 6 x + 3( log 3 9 − log 3 x ) x
f ( x ) + f 1 = log 6 + 3 log 3 9 x − log 6 x + 3( log 3 9 − log 3 x ) x
f ( x ) + f 1 = 3 ⋅ ( log 3 9 + log 3 x ) + 6 − 3 log 3 x = 6 + 3 log 3 x + 6 − 3 log 3 x = 12 x
43. y = − ln x − 2
− ln x − 2 = 0 ln x = −2 nula funkcije 1 x= 2
22
x
y = −2 − ln x > 0
1 x ∈ 0, 2
1 x ∈ 2 ,+∞
y = −2 − ln x < 0 y
y = − ln x − 2 x 1 2
44. y = sin x
x 0 y 0
π 6 1 2
π 4
1
π 3
2 2
3 2
π 2
π
3π 2
2π
1
0
-1
0
sin ( x + 2kπ ) = sin x k = 0,±1,±2,±3... sin x > 0 , x ∈ ( 0 + 2kπ , π + 2kπ )} k ∈ Z sin x < 0 , x ∈ ( π + 2kπ ,2π + 2kπ )
π π x ∈ − + 2kπ , + 2kπ y ↑1−1 2 2 3π π x ∈ + 2kπ , + 2kπ y ↓1−1 2 2 y
1
y=sinx x 0
-1
23
π
2π
45. y = arcsin x
x
0
1 2
arcsin x
0
π 6
D : −1≤ x ≤1
2 2
3 2
π 4
π 3
1
0
-1
0
π 2
π
3π 2
2π
y (0,π)
x -1
0
1 y=arcsinx
1 y=sinx -2π
-π
0 -1 y=arcsinx
24
π
2π
46. y = cos x
1 y=cosx -2π
−
3π 2
-π
−
π
0
2
π
3π 2
π
2 -1
x = ( 2k + 1) ⋅
cos x = 0, cos x > 0, cos x < 0,
47. y = arccos x
π 2
,(k ∈ Z )
π π x ∈ − + 2kπ , + 2kπ 2 2 3π π x ∈ + 2kπ , + 2kπ 2 2
3π 2
x ∈ ( 0, π ) y ↓1−1
π
x ∈ ( π ,2π ) y ↑1−1
2
sin x 48. y = tgx = cos x D:
π 2 sin x = 0 ⇒ x = kπ ( k ∈ Z )
cos x ≠ 0; x ≠ ( 2k + 1) ⋅
tgx = 0
-1
0
1
−
π 2
y=arccosx
−
25
3π 2
2π
y
−
3π 2
−π
−
π 2
0
y=tgx
π
π 2
3π 2
2π
5π 2
y
3π 2
π
π 2
x
0
−
π 2
−π
−
cos x sin x D : sin x ≠ 0 ⇒ x ≠ kπ
3π 2
49. y = ctgx = ctgx = 0
26
cos x = 0 ⇒ x = ( 2k + 1) ⋅
π 2
(k ∈ Z)
x
y
−π
−
π 2
0
y=ctgx
π
π 2
y = arcctgx
2π
3π 2
x
y
2π 3π 2 π
π 2
0 x −
π 2
−π
2x − 3 x+3 D: x+3≠ 0 x ≠ −3 x = −3 vertikalna asimptota y = 0 2x − 3 = 0 -3 3 Znak funkcije x= 2 0 y +
50. y =
2x − 3 x+3
27
+ + -
0
+ + +
y
y=2 2 x
3 2
51. y = shx =
x − − x 2
D=R y = shx = 0
(sinus hiperbolički x)
⇒
x = 0 nula funkcije − x − x x − − x y( − x ) = =− = − y ( x ) funkcija je neparna 2 2 y y=shx x
y
x + − x 52. y = chx = 2 D=R y min ( 0 ) = 1
y=shx
y − x + x x + − x y( − x ) = =− = y ( x ) funkcija je parna 2 2
shx x − − x = 53. y = thx = chx x + − x
x 0
28
x y=1
y=thx y=-1
54. y = cthx =
chx x + − x = shx x − − x
y
y=1 x 0
y=cthx y=-1
Granične vrijednosti funkcije Niz { a n } realnih brojeva ima graničnu vrijednost a ako za proizvoljan ε > 0 postoji prirodan broj n0 takav da je za svaki n > n0 ispunjena apsolutna vrijednost ( a n − n ) ≤ ε označavamo sa
an = a lim n →∞
. Niz koji ima graničnu
vrijednost nazivamo ga konvergetnim, a onaj koji nema vrijednosti nazivamo divergetnim. an =
1 n
0
1 4
1 1 3 2
1
(a-ε, a+ε) - epsilon okoline tačke a
55. a n =
29
5n − 2 n+2
a-ε
(
a
)
a+ε
ε okoline tačke a
an − 5 < ε an − 5 <
ε = 0,1
1 10
5n − 2 1 −5 < n+2 10 5n − 2 − 5n − 10 1 < n+2 10 − 12 1 < n + 2 10 − 120 < n + 2 n > −122 a 0 x n + a1 x n −1 + ⋅ ⋅ ⋅ + a n −1 ⋅ x + a n
lim n n −1 + ⋅⋅⋅ + b n →∞ b x + b x 0
n −1
1
⋅ x + bn
a0 x n + a1 x n −1 + ⋅ ⋅ ⋅ + a n
lim n+ k + bx n + k +1 + ⋅ ⋅ ⋅ + b n →∞ b x 0
lim x →∞ a
−
m n
58.
59.
60.
30
= 0 ,(k ∈ N )
b0 x n + b1 x n −1 + ⋅ ⋅ ⋅ + bn
=∞
1
=
n
am
6
n + 25n
n + 25n / : n
= lim lim 3 x →∞ 8n18 − 4n + 5 x→∞ 3 8n18 − 4n + 5
2
57.
a0 b0
n
a 0 x n+ k + a1 x n + k −1 + ⋅ ⋅ ⋅ + a n+ k
6
56.
=
x +x
= lim lim 5 x →∞ x − 1 x →∞
lim x → −∞ lim x →∞
1 x
3
−
=
1 2
=
1 1 2
6
/ : n6
= lim x →∞
1 1 + 4 3 x x = 0 =0 1 1 1− 5 x =
3
1 3
x −1 x −1 / : x = lim 2 = lim 2 x / : x3 x →∞ x x →∞
1 x3 = 1 = ∞ 1 0 x
1−
25 1 1 n5 =3 = 4 5 8 2 8− 5 + 6 n n 1+
3
(
)
2 2 lim x x + 2 − x − 2 = lim x →∞
= lim x →∞
(
x ⋅ x2 + 2 − x2 + 2
)=
x2 + 2 + x2 − 2 4
x⋅
(
4
)
x −1
lim 4 4 x →1 x ⋅ ( x − 1) ⋅ ( x + 1) ⋅ (
61.
x⋅
(
)(
x2 + 2 − x2 − 2 ⋅
x2 + 2 + x2 − 2
x →∞
4x
lim x →∞
)
x +1
( )
x2 + 2 + x2 − 2
x2 + 2 + x2 − 2 = lim x →1
(
x⋅
)(
(
4 4
=
4 =2 2
x
)(
x +1 ⋅
)=
=
)
x +1
)
1 1 = 1⋅ 2 ⋅ 2 4
1− 3 x 3 x − 1 = 3 x − 13 = 3 x − 1 3 x 2 + 3 x + 1 x −1 1− 3 x 1− 3 x 1 1 1 = = lim − =− =− lim lim 3 2 3 2 1+1+1 3 x →1 x − 1 x →1 3 x − 1 x →1 x + 3 x +1 x + 3 x +1
62. y =
(
63.
)(
)
(1 − sin x )(1 + sin x ) cos 2 x 1 − sin 2 x 1 + sin x = limπ 1 − sin 3 x = limπ 1 − sin 3 x = limπ (1 − sin x ) 1 + sin x + sin 2 x = lim 2 x →0 1 + sin x + sin x x→ x→ x→ 2
2
2
(
)
1+1 2 = 1+1+1 3 x x 1 = sin 2 + cos 2 2 2 (-) x x 2 x 2 x cos x = cos + = cos − sin 2 2 2 2 x x x x 1 − cos x = sin 2 + cos 2 − cos 2 + sin 2 2 2 2 2 x 1 − cos x = 2 sin 2 2 x 2 sin 2 1 − cos x 2 =2 = lim 64. lim x →0 sin 2 x x →0 sin 2 x 2 2 3 x 65. y = 2 x −1 D : x2 −1 ≠ 0 =
x2 ≠ 1 x1, 2 ≠ ±1 x3 ( − 1) 3 = − 1 = − 1 = ∞ = Funkcija ima vertikalne asimptote lim lim 2 2 1−1 0 x → −1 x − 1 x →−1 ( − 1) − 1 x3 13 1 1 = = = =∞ lim lim 2 2 1−1 0 x →1 x − 1 x →1 1 − 1 x3 1 1 = lim = =∞ lim 2 nema horizontalne asimptote 0 x →∞ x − 1 x →∞ 1 − 1 2 x x 31
k = lim x →∞
x3 x3 1 x2 −1 = = =1 lim 3 x 1 x →∞ x − x
1 3 3 x3 x3 x −x +x 0 n = lim 2 − kx = lim 2 − x = lim = lim x = = 0 2 1 x −1 x →∞ x − 1 x →∞ 1 − 1 x →∞ x − 1 x →∞ 2 x 3 y = x Kosa asimptota funkcije y = x . y x2 −1 x 66. y = 3 − x2 D : 3 − x2 ≠ 0 x2 ≠ 3
x
x1, 2 ≠ ± 3
-1 − 3
x
= lim lim 2 x→− 3 3 − x x →− 3
(
3− − 3
x
= lim lim 2 3 − x x→ 3 x→ 3
3
3−
( 3)
2
=
)
2
=
− 3 − 3 = =∞ 3−3 0
x3 y= 2 x −1
3 3 = =∞ 3−3 0
Ima vertikalnu asimptotu, a kose asimptote nema. x
= lim lim 2 x →∞ 3 − x x →∞
1 x
3 −1 x2
=
0 = 0 Horizontalna asimptota je x – osa. −1 y
− 3
0
x
3
x y= 3 − x2 x2 +1 1− x2 D : 1− x2 ≠ 0
67. y =
32
x 2 ≠ 1 x1, 2 ≠ ±1
1
2
2
x +1 / : x = lim / : x2 x →∞
y = lim lim 2 x →∞ x →∞ 1 − x
1 x 2 = 1 = −1 Horizontalna asimptota y=-1. 1 −1 −1 x2
1+
x2 +1 ( − 1) 2 + 1 2 = lim = =∞ lim 2 2 0 x → −1 1 − x x → −1 1 − ( − 1) x2 +1 12 + 1 2 = = =∞ lim lim 2 2 0 x →1 1 − x x →1 1 − 1
Vertikalne asimptote x= -1 i x=1.
Nema nula funkcije. y
x -1
0
1 y= -1
-1 x= -1
x=1
2
x 3− x D: 3− x ≠ 0 x≠3 x2 32 9 = = = ∞ Vertikalna asimptota je x=3 . lim lim 0 x →3 3 − x x →3 3 − 3
68. y =
x2 x2 1 1 k = lim 3 − x = lim = lim = = −1 2 x −1 x →∞ x →∞ 3 x − x x →∞ 3 − 1 x 2 2 x x x 2 + 3x − x 2 3x n = lim − kx = lim + x = lim = lim = −3 3 − x 3 − x 3 − x x →∞ 3 − x x → ∞ x → ∞ x → ∞ y = kx + n y y = − x − 3 Kosa asimptota x 0 -3
y = − x− 3
Horizontalne asimptote nema.
y
-3
0 x
-3
0
-3
33
3
3 x − 1 D: x − 1 ≠ 0
69. y =
y
x ≠ 1 x≠0
x ln x D : ln x ≠ 0 x ≠1
x
x=0
70. y =
x>0
y
ovdje funkcije nema
x 1
x=1 y=f(x)
f ( x +∆y )
∆y
B
- priraštaj funkcije def .
∆ y = f ( xračun Diferencijalni + ∆ x ) − f ( x ) f ( ′x ) =
f ( x)
A( x, f ( x ) ) x
34
- priraštaj argumenta x
∆x
x + ∆x
lim ∆x→ 0
f ( x+ ∆x ) − f ( x ) ∆x
∆y =k ∆x k – koeficijent smjera prave (sekant)
tgα =
B
∆y α
α
A( x, f ( x ) )
∆x
x
∆x → 0 B →A s →t
x + ∆x
t
α – ugao između sekante i x- ose
f ( x+ ∆ x ) − f ( x ) f ( ′x ) = lim = k t A( x, f ( x ) ) ∆x ∆ x→ 0
71. f ( x ) = x + 2 f ( x + ∆x ) = x + ∆x + 2 f ( ′x ) = lim ∆x →0
f ( x + ∆x ) − f ( x ) ∆x
= lim ∆x → 0
x + ∆x + 2 − x − 2 ∆x = lim =1 ∆x ∆x →0 ∆x
x′ = 1
( x + C)′ = 1
72. y = C
f( x) = C f ( x + ∆x ) = C
73. f ( x ) = x
35
f ( ′x ) = lim ∆x →0
C −C 0 = lim =0 ∆x ∆x →0 ∆x
y=C
y′ = 0
f ( x + ∆x ) = x + ∆ x x + ∆x − x x + ∆x + x x + ∆x − x ⋅ = lim = ∆x x + ∆x + x ∆x→0 ∆x ⋅ x + ∆x + x ∆x →0 ∆x 1 = lim = x + ∆x + x 2 x ∆x →0 ∆x ⋅ f ( ′x ) = lim
(
(
)
2
x x −1 ( x + ∆x ) 2 f ( x + ∆x ) = ( x + ∆x ) − 1
74. f ( x ) =
( x + ∆x ) 2 − x 2 ( x + ∆x ) − 1 x − 1 =
f ( ′x ) = lim
∆x
∆x →0
= lim ∆x →0
76. 77. 78.
(x lim ∆x →0
2
)
+ 2 x ⋅ ∆x + ∆x 2 ⋅ ( x − 1) − x 2 ( ( x + ∆x ) − 1) ( ( x + ∆x ) − 1) ⋅ ( x − 1) = ∆x
x 3 + 2 x 2 ∆x + ∆x 2 x − x 2 − 2 x∆x − ∆x 2 − x 3 − x 2 ∆x + x 2 = ∆x ⋅ ( ( x + ∆x ) − 1) ⋅ ( x − 1)
(
)
∆x ⋅ x 2 − 2 x + x∆x − ∆x x 2 − 2x = ( x − 1) 2 ∆x →0 ∆x ⋅ ( x + ∆x − 1)( x − 1) ′ 3x 2 + 2 x − 5 = 6 x + 2 ′ x3 1 2 1 1 − x + arctgx = 3 x − 1 + = x2 −1+ 2 3 3 1+ x 1+ x2 7 3 ′ 7 4 4 7 4 8 ⋅ x = 8 ⋅ x = 8 ⋅ ⋅ x = 14 ⋅ 4 x 3 4 ′ 1 1 2 1 −5 2 1 x − 2 − 5 = 1+ 3 − ⋅ 6 = 1+ 3 + 6 5 x x 5x x x x
= lim
75.
)
(
)
(
)
79.
′ 2 1 1 16 + 2+1 ′ 19 ′ 19 −5 ′ 1 3 2 4 3 12 24 24 24 19 24 −1 19 24 19 = x = x = ⋅x = ⋅x = ⋅ x ⋅ x⋅ x = x ⋅x ⋅x 24 24 24 24 x 5 f ( ′x ) = lim
f ( x + ∆x ) − f ( x ) ∆x
∆x → 0
f ( x + ∆x ) = ( x + ∆ x ) 3
80. f ( x ) = x 3 f ( ′x ) = lim ∆x →0
= lim ∆x → 0
y=x
36
( x + ∆x ) 3 − x 3
(
∆x 2
y ′ = n ⋅ x n −1
( a) − ( b) = ( 3
= lim ∆x →0
∆x ⋅ 3 x + 3x∆x + ∆x ∆x
n
a−b =
Izvod
3
3
3
3
2
)
x 3 + 3 x 2 ∆x + 3 x ⋅ ∆x 2 + ∆x 3 − x 3 = ∆x
) = 3x
a −3 b ⋅
(
3
2
a 2 + 3 ab + 3 b 2
)
81. f ( x ) = 3 x
f ( x + ∆x ) = 3 x + ∆ x
3 ( x + ∆x ) 2 + 3 ( x + ∆x ) ⋅ x + 3 x 2 x + ∆x − 3 x = f ( ′x ) = lim ⋅ 2 3 2 ∆ x 3 ∆x →0 ( x + ∆x ) + 3 ( x + ∆x ) ⋅ x + x x + ∆x − x ∆x = lim = lim = 2 2 3 3 3 ( x + ∆x ) ⋅ x + 3 x 2 3 ( x + ∆x ) ⋅ x + 3 x 2 ∆x →0 ∆x ⋅ ∆ x → 0 ( ) ( ) x + ∆ x + ∆ x ⋅ x + ∆ x + 1 1 1 = lim = lim = 3 3 3 3 2 2 2 2 3 2 ∆x → 0 3 x2 3 ( x + ∆x ) + 3 ( x + ∆x ) ⋅ x + x ∆x→0 x + x + x ∆x − 1 82. f ( x ) = x f ( x + ∆x ) = x + ∆x =1 ∆x x + ∆x − x x ⋅ ∆x − 1 f ( ′x ) = lim = lim = x ∆ x ∆ x ∆x →0 ∆x → 0 f ( x + ∆x ) = sin ( x + ∆x ) 83. f ( x ) = sin x 3
(
(
)
)
2 cos
x + ∆x + x x + ∆x − x ⋅ sin 2 2 = ∆x
sin ( x + ∆x ) − sin x = lim ∆x ∆x →0 ∆x →0 2 x + ∆x ∆x cos ⋅ sin 2 2 = cos 2 x = cos x = lim ∆x 2 ∆x →0 2 α +β α −β sin α − sin β = 2 cos ⋅ sin 2 2 ′ f ( x ) = sin x f ( x ) = cos x f ( ′x ) = lim
Izvodi složenih funkcija n
u = n⋅u
n −1
( )′ = u
u
⋅ u′
⋅ u′
( sin u ) ′ = cos u ⋅ u ′
( cos u ) ′ = − sin u ⋅ u ′
( tgu ) ′ =
( arctgu ) ′ =
′ u
u′ cos 2 u
( ln u ) ′ = 1 ⋅ u ′ = u
(
u
)′
84. x 2 − x + 2 = x 2 − x +2 ⋅ ( 2 x − 1) 3 2 85. (tg x − 3tgx + 3x ) = 3tg x ⋅
′
1
86. (ln ( x − x − 1) )′ = 2 x
−
1 1 − 3⋅ +3 2 cos x cos 2 x 1
2 x −1 x − x −1
37
u′ 1+ u2
87.
′ 1 −1 ′ sin 2 x 2 1 sin 2 x sin 2 x ′ ⋅ ⋅ 1 − sin 2 x 2 1 − sin 2 x 1 − sin 2 x ln sin 2 x = = = 1 − sin 2 x sin 2 x sin 2 x 1 − sin 2 x 1 − sin 2 x 1 2
′ sin 2 x ( sin 2 x ) ′ ⋅ (1 − sin 2 x ) − (1 − sin 2 x ) ′ ⋅ sin 2 x ⋅ (1 − sin 2 x ) 2 1 − sin 2 x == = sin 2 x sin 2 x sin 2 x 2 2 ⋅ 1 − sin 2 x 1 − sin 2 x 1 − sin 2 x ( cos 2 x ⋅ 2) ⋅ (1 − sin 2 x ) − ( 0 − 2 cos 2 x ) ⋅ sin 2 x 2 cos 2 x − 2 sin 2 x ⋅ cos 2 x + 2 cos 2 x ⋅ sin 2 x (1 − sin 2 x ) 2 = = = sin 2 x 2 sin 2 x(1 − sin 2 x ) 1 − sin 2 x 2 cos 2 x ctg 2 x = = 2 sin 2 x(1 − sin 2 x ) 1 − sin 2 x ′ u u ′v − uv ′ ′ ′ ′ ′ ′ ′ ′ ′ (c ⋅ u) = c ⋅ u ( u ± v) = u ± v ( u ⋅ v) = u ⋅ v + u ⋅ v = v2 v sin 2 x 1 − sin 2 x =
−
88.
[x ⋅ ln(x + 1 + x ) − 1 + x ]′ = (x ⋅ ln(x + 1 + x ) ′ − ( 1 + x )′ = ′ 1 = x ′ ⋅ ln ( x + 1 + x ) + (ln ( x + 1 + x ) ⋅ x − ⋅ 2x = 2 1+ x ′ 2x ( x + 1+ x ) = = ln ( x + 1 + x ) + ⋅ x − 2
2
2
2
2
2
2
2
2
2 1+ x2
x + 1+ x2
)
(
(
)
x′ + 1 + x 2 x = ln x + 1 + x 2 + ⋅ x − 1+ x2 x + 1+ x2
( = ln ( x +
) )
= ln x + 1 + x 2 +
89.
38
1+ x2
1+ x2 + x 1+ x2 x + 1+ x2
⋅x−
x 1+ x2
)
(
1+
2x
x 2 1+ x2 ⋅ x − = ln x + 1 + x 2 + = 2 2 x + 1 + x 1 + x
(
)
= ln x + 1 + x 2 +
x x + 1+ x2
−
x x + 1+ x2
=
′ ′ ′ 2 x a2 x x a x 2 2 2 2 2 a − x + 2 arcsin a = 2 ⋅ a − x + 2 arcsin a = ′ x 1 + ′ a2 1 a = 2 2 2 2 ′ = x ⋅ a − x + a − x ⋅ x + 2 2 2 x 1 − a 1 2 a 2 1 x 1 1 a2 − x2 x2 a 2 = a −x + ⋅ −2 x ⋅ + ⋅ ⋅ = − + = 2 2 2 2 2 2 2 2 2 a 2 2 2 a −x 2 a −x a −x x 2 1− a2 a
(
( =
a2 − x2
)
2
− x2 + a2
2
2 a −x
1 90. y = 1 +
2
)
=
2a 2 − 2 x 2 2
2 a −x
2
=
(
2 a2 − x2 2
2 a −x
)
2
2
= a2 − x2
x
x x
1 1 ln y = ln1 + = x ⋅ ln1 + x x
′ y′ 1 1 ′ = x ⋅ ln1 + + ln1 + ⋅ x y x x y′ 1 −1 1 = ln1 + + ⋅ 2 ⋅x y x 1 x 1 + x y′ 1 −1 1 = ln1 + + ⋅ 1 x y x 1+ x y′ 1 1 = ln1 + − y x 1 x ⋅ 1 + x x 1 1 1 ⋅ 1 + y ′ = ln1 + − x x 1 x ⋅ 1 + x ln y = x ⋅ ln x ⋅ ( sin x ) 91. y = ( sin x ) x y′ ( sin x ) ′ = ln( sin x ) + x ⋅ cos x = ln ( sin x ) + x ⋅ y sin x sin x
Funkcije
39
A=B ln A = ln B ln x n = n ⋅ ln x
x ⋅ cos x y ′ = ln ( sin x ) + ⋅ ( sin x ) x sin x
92. y = x 3 − 6 x 2 + 9 x − 4 1. Oblast definisanosti D : ∀x ∈ R 2. Parnost funkcije y ( − x ) = ( − x ) 3 − 6 ⋅ ( − x ) 2 + 9( − x ) − 4 = − x 3 − 6 x 2 − 9 x − 4 funkcija niti je parna niti je neparna. 3. Periodičnost funkcije ( ∀ω ≠ 0) funkcija nije periodična y ( x +ω ) ≠ y ( x ) 4. Nule funkcije x3 − 6x 2 + 9x − 4 = 0 x1 = 1
x 3 − 6 x 2 + 9 x − 4 : ( x − 1) = x 2 − 5 x + 4 3
x −x
x 2 − 5x + 4 = 0 x 2 + x3 = 5
2
- 5x 2 + 9x − 4
x 2 ⋅ x3 = 4
- 5x 2 + 5x 4x − 4 4x − 4 ( 0) ( x − 1) ⋅ ( x − 1) ⋅ ( x − 4) = y
x2 = 1 x3 = 4
5. Znak funkcije -∞
1
( x − 1) 2
+
x−4
-
0
-
y
4
+
0
6. Prvi izvod funkcije
(
+∞
y > 0 x ∈ ( 4,+∞ )
+
y < 0 x ∈ ( − ∞ ,1) ∪ (1,4 )
-
0
+
-
0
+
)
y ′ = 3 x 2 − 12 x + 9 = 3 x 2 − 4 x + 3 = 3 ⋅ ( x − 1) ⋅ ( x − 3)
7. Znak prvog izvoda funkcije -∞
3 x −1 x−3
y′ y
8. Grafik funkcije
40
1
+ +
0
3
+∞
+
+
y max (1) = 0
+
+
y min ( 3) = −4
-
-
0
+ +
y
y = x3 − 6x 2 + 9x − 4 x
(1,0) 0
2
1
3
4
-1 -2 -3 -4
93. y = x 3 − 3x + 2 1. Domen D = R = ( − ∞,+∞ ) 2. Parnost y ( − x ) = ( − x ) 3 − 3( − x ) + 2 = − x 3 + 3x + 2 = −( x 3 − 3x − 2) nije ni parna ni neparna. 3. Periodičnost y ( x +ω ) ≠ y ( x )
ω≠0
y ( x +ω ) = ( x + ω ) 3 − 3 ⋅ ( x + ω ) + 2 = x 3 + 3 x 2ω + 3xω 2 + ω 3 − 3 x − 3ω + 2
periodična. 4. Nule x 3 − 3x + 2 = 0 x = 1 pogođena nula
x 3 − 3 x + 2 : ( x − 1) = x 2 + x − 2 x3 − x 2
x2 + x − 2 = 0 x 2 + x 3 = −1
x 2 − 3x + 2
x 2 ⋅ x 3 = −2
x2 − x − 2x + 2 − 2x + 2 ( 0) ( x − 1) ⋅ ( x − 1) ⋅ ( x + 2) = y
x 2 = −2 x3 = 1
-∞
5. Znak( x − 1) 41
x+2 y
2
-2
+
1
+
-
0
-
0
0
+ +
+∞
+ +
0
+
nije
6. Prvi izvod
(
)
y ′ = 3 x 2 − 3 = 3 x 2 − 1 = 3 ⋅ ( x − 1) ⋅ ( x + 1) y′ = 0 x =1 x = −1
7. Znak prvog izvoda -∞
-1
1
+∞
y max ( −1) = 4
x −1
-
x−3
-
+
y′
0
0
+ -
+
y min (1) = 0
+ +
y
8. Grafik
y = x3 − 3x + 2 4
y
3 2 1 x -2
94. y =
-1
0 (1,0)
4x 4 − x2
1.) Domen 4 − x 2 ≠ 0
x ≠ ±2 4 ⋅ ( − x) − 4x 4x = = − Neparna funkcija 2.) Parnost y ( − x ) = 2 2 4− x 4 − x2 4 − ( − x)
3.) Periodičnost
42
∀ω ≠ 0
y ( x +ω ) ≠ y ( x )
4.) Nule funkcije y=0
4x = 0 ⇒
x=0
5.) Znak funkcije -∞
-2
-
4x
2− x 2+ x
0
- 0 +
+ + - 0 + + -
y
6.) Prvi izvod
( 4x) ′ ⋅ (4 − x 2 ) − (4 − x 2 ) y′ =
′
(4 − x )
⋅ 4x
2 2
=
(
4x
4 ⋅ ( − 2)
4x
4 ⋅ ( 2)
4x
4 x
= lim lim 2 2 x → −2 4 − x x → −2 4 − ( − 2 ) = lim lim 2 2 x →2 4 − x x → −2 4 − ( 2 )
4 −1 x2
=
=
=
+∞
+
+ 0 + +
)
+ -
4 ⋅ 4 − x 2 + 2x ⋅ 4x
Funkcija uvijek raste y ↑ ( ∀x ∈ D ) 7) Asimptote
= lim lim 2 x →∞ 4 − x x →∞
2
(4 − x )
2 2
=
16 − 4 x 2 + 8 x 2
(4 − x )
2 2
=
4 x 2 + 16
(4 − x )
2 2
−8 =∞ 0
8 =∞ 0
vertikalne asimptote su x= -2 i x= 2.
0 = 0 horizontalna asimptota je y =0. −1 y
Kose asimptote nema. 8) Grafik
y=
4x 4 − x2 x
-2
x= -2 43
> 0 ∀x
-1
0
1
2
x=2
y=0
95. y =
x3
2( x + 1) 2
1.) Domen D : 2( x + 1) 2 ≠ 0
( − x) 3
2.) Parnost y ( − x ) =
2( − x + 1) 2 3.) Periodičnost y ( x +ω ) ≠ y( x )
x ∈ ( − ∞,−1) ∪ ( − 1,+∞ )
x ≠ −1 =
− x3
2( x − 1) 2 ∀ω ≠ 0
funkcija nije ni parna ni neparna.
4.) Nule funkcije x3 = 0
y=0
5.) Znak funkcije
⇒
-∞
x=0 -1
x3
0
-
2( x + 1)
2
+
0
-
y
( x ) ⋅ (2 ⋅ ( x + 1) ) − (2 ⋅ ( x + 1) ) y′ = ′
2
2
-
+
y′ = y′ = y′ =
6 x ( x + 1) − ( 2 ⋅ ( 2 x + 2) ) ⋅ x
(2( x + 1) )
2 2
6 x 4 + 12 x 3 + 6 x 2 − 4 x 4 − 4 x 3
(2( x + 1) )
2 2
3
(
)
(
)
2
(
(
) (
2
)
4
6x x + 2x + 1 − 4x + 4x
= =
(2( x + 1) )
2 2
2 x 4 + 8x 3 + 6 x 2
)
4( x + 1)
4
=
3
)
(
)
2x 2 ⋅ x 2 + 4x + 3 4( x + 1)
4
x 2 ⋅ x 2 + 4x + 3 2( x + 1) 4
y′ = 0
x2 = 0 x1 = 0
x 2 + 4x + 3 = 0 x 2 + x 3 = −4
∨
x 2 ⋅ x3 = 3
( x + 3) ⋅ ( x + 1)
-∞
7.) Znak prvog izvoda
-3
-1
0
+∞
x2
+
+ 0 +
+
x+1 x+3
- 0 + - 0 + + + + 0 +
+ + +
+
+
y′ y
44
3
(
′ 3 x 2 ⋅ 2( x + 1) 2 − x 3 ⋅ 2 x 2 + 2 x + 1 ⋅x = 2 2 2 ⋅ ( x + 1)
′
2 2
2
+ +
(2 ⋅ ( x + 1) )
2
0
+
6.) Prvi izvod funkcije 3
+∞
-
+
y max ( −3) = −
27 8
8.) Asimptote
( − 1) 3 = lim lim 2 2 x →−1 2 ⋅ ( x + 1) x → −1 2 ⋅ ( − 1 + 1) x3
x3
=
−1 = ∞ vertikalna asimptota x= -1. 0
1 1 = =∞ 4 2 nema horizontalne asimptote. 0 + 2 + 3 x x x
= lim lim 2 x →∞ 2 ⋅ ( x + 1) x →∞ 2 x3
x3 1 1 2 ⋅ ( x + 1) 2 k = lim = lim 3 = lim = 2 x 2 x →∞ x →∞ 2 x + 4 x + 2 x x →∞ 2 + 4 + 2 2 x x 3 3 3 2 x − x − 2x − 2x x 1 − 2 x2 + x −1 n = lim − x = lim = = −1 2 2 = lim 2 x →∞ 1 2 ⋅ ( x + 1) 2 x →∞ 2 ⋅ ( x + 1) x→∞ 2( x + 1) y = kx + n
(
x3 1 y = x − 1 kosa asimptota funkcije y = . 2 2( x + 1) 2
x
2
0
y
0
-1
9.) Grafik y
y=
-3
-2
-1
0 -1
27 − 3,− 8
-2 -3 -4
x= -1
45
1
2
)
x3
2 ⋅ ( x +1) 2
x
96. y = x ⋅ − x D : ( − ∞,+∞ ) 1.) Domen ∀x ∈ R 2.) Parnost y ( − x ) = ( − x ) ⋅ −( − x ) = − x ⋅ x funkcija nije ni parna ni neparna. 3.) Periodičnost Nije periodična 4.) Nule funkcije y=0
x=0
5.) Znak funkcije
-∞
0
+∞
x
-
x
+
+
y
-
+
0
+
6.) Prvi izvod funkcije
′ x x x x 1 ⋅ − ⋅ x ⋅ (1 − x ) 1 − x y′ = x = = = x 2 x 2 x y′ = 0 ⇒ 1− x = 0 x =1
7.) Znak prvog izvoda -∞
1
1− x
+
x
+
y′
0
+∞
-
y max (1) =
+
+
0
-
y
8.) Asimptote x
= lim lim x x →∞ x →∞
9.) Grafik
x′
( ) x
′
= lim x ←∞
1 1 = = 0 horizontalna asimptota y = 0. x ∞ y
x 0
1
2
−x
y = x⋅ 46
1
97. y =
ln x x
1.) Domen D : x > 0 ∧ x ≠ 0 2.) Parnost Funkcija u ( − x ) uopšte nije definisana, nije parna ni neparna. 3.) Periodičnost Nije periodična. 4.) Nule funkcije y=0
ln x = 0 ⇒ x = 1
5.) Znak funkcije
0
1
+∞
ln x
-
x
+
+
y
-
+
0
+
6.) Prvi izvod funkcije 1 ⋅ x − 1 ⋅ ln x 1 − ln x x y′ = = 2 x x2 y′ = 0 1 − ln x = 0 ln x = 1 ⇒
x=
7.) Znak prvog izvoda 0
1− ln x
+∞
+
0
+
y′
-
y max ( ) =
+
+
0
1
-
y
8.) Asimptote 1 ln x 1 = lim x = lim = 0 horizontalna asimptota je x – osa. lim x →∞ x x →∞ 1 x →∞ x
9.) Grafik
y
ovdje funkcija nema vrijednosti 47
0
1
2
ln x y= x
x
98. y =
x 2 + 3x x+4
x+4≠0
1.) Domen D : 2.) Parnost y( − x )
( − x) 2 + 3 ⋅ ( − x) =
=
−x+4
3.) Periodičnost y ( x +ω ) ≠ y ( x )
x ∈ ( − ∞,−4 ) ∪ ( − 4,+∞ )
x ≠ −4
− x 2 + 3x x 2 − 3x nije parna ni neparna. = − −x+4 x − 4
∀ω ≠ 0
4.) Nule funkcije
x 2 + 3x = 0 x( x + 3) = 0 x = 0 ∧ x = −3
5.) Znak funkcije -∞
x
-4
-
-3
0
+∞
- 0 -
x+3 x+ 4
- 0 + - 0 + + y + 6.) Prvi izvod funkcije y′ = y′ =
y > 0 x ∈ ( − 4,− 3) ∪ ( 0,+∞ )
+
y < 0 x ∈ ( − ∞ ,− 4) ∪ ( − 3,0 )
+ + +
( 2 x + 3) ⋅ ( x + 4) − 1 ⋅ ( x 2 + 3x ) = 2 x 2 + 3x + 8 x + 12 − x 2 − 3x ( x + 4) 2 ( x + 4) 2 x 2 + 8 x + 12
( x + 4) 2
7.) Znak prvog izvoda y′ = 0 x1 = −2
x 2 + 8 x + 12 = 0 x 2 = −6
-∞
x+2
( x + 4) 2
x+6 y′
-6
+ +
0 0
-2
+ + -
0
+∞
+ + + +
y max ( −6 ) = −6 y min ( −2 ) = −1
y
8.) Asimptote
x 2 + 3x ( − 4 ) 2 + 3 ⋅ ( − 4 ) 16 − 12 4 = lim = = = ∞ vertikalna asimptota x=- 4. lim −4+4 0 0 x → −4 x + 4 x → −4
k = lim x →∞
48
x 2 + 3x 3 1+ 2 x + 3x x+4 = x = 1 =1 = lim lim 2 x 1 x →∞ x + 4 x x →∞ 1 + 4 x
x 2 + 3x x 2 + 3x − x 2 − 4 x −x −1 = lim n = lim − x = lim = = −1 x+4 x →∞ x + 4 x →∞ x →∞ x + 4 1 y = x − 1 kosa asimptota x
1
0
y
0
-1
9.) Grafik y
y=x-1
-6
-5 -4
-3
-2
-1
( − 2,−1)
0
1 -1 -2 -3 -4 -5 -6 -7
( − 6,−9)
-8 -9
x= -4
49
2
3
4
5
6
x
1
99. y = x ⋅ x 1.) Domen D : 2.) Parnost
x≠0 −
y( − x ) = ( − x ) ⋅
1 x
=
3.) Periodičnost
−x 1 x
( ∀ω ≠ 0) nije periodična.
y ( x +ω ) ≠ y ( x )
4.) Nule funkcije 1 x ⋅ x
y=0 ⇒
x = 0 nije iz domena i funkcija nema nula.
=0
5.) Znak funkcije y=
1 x ⋅ x
>0
za
x>0
y=
1 x ⋅ x
<0
za
x<0
6.) Prvi izvod funkcije y′ =
1 ′ x ⋅ x
1 ′ 1 1 1 1 1 1 ′ 1 −1 x 1 1 x x x x x x + x⋅ = 1⋅ + x ⋅ ⋅ = + x ⋅ ⋅ 2 = − = x ⋅ 1 − x x x x
7.) Znak prvog izvoda y′ = 0 x = 1 y min (1) =
-∞
0
x− 1
1 x
x
y′
1
+∞
+
+
0
+ +
-
+
+
+
-
+
y min ( 1) =
y
8.) Asimptote 1
1
(
)
1
)
1
x x ⋅ − 1 ⋅ x −2 1 1 x = y = = = = =0 lim lim lim lim lim −2 1 − − 1 − − − ∞ − − 1 x x →0 x →0 x →0 x →0 x →0 x x
(
y = lim lim x →0 x →0 +
+
1 x
1 x
= lim x →0 +
1 x
(
1
⋅ − 1 ⋅ x −2 = lim x = 0 = ∞ = +∞ −2 − 1⋅ x x →0 +
vertikalne asimptota x=0.
50
(
)
)
k = lim
1 x ⋅ x
x
x →∞
= lim
1 x
= 0 = 1
x →∞
′ 1 x − 1 1 1 1 1 x −1 x ⋅ − 1 ⋅ x −2 = n = lim x ⋅ x − x = lim x ⋅ x − 1 = lim = lim = lim −2 ′ x →∞ x →∞ 1 − 1 ⋅ x x →∞ x → ∞ x → ∞ 1 x x
(
=
1 x
= 0 = 1
y = x + 1 kosa asimptota funkcije y=
1 x ⋅ x
.
x
-1
y
0
0 1
9.) Grafik y
(1, ) y=
1 x ⋅ x
1 -3
-2
-1
0 -1
1
2
x
-2 -3
100. y = (3 − x 2 ) ⋅ x 1.) Domen D : 2.) Parnost
(
( ∀x ∈ R ) .
)
(
)
1 y ( − x ) = 3 − ( − x ) 2 ⋅ − x = 3 − x 2 x funkcija nije ni parna ni neparna.
3.) Periodičnost. Funkcija nije periodična. 4.) Nule funkcije -∞ y=0
3 − x2 = 0
5.) Znak funkcije 51
x1, 2 = ± 3
3− x
+ +
3+x
-
y
+
x
+ + 0
+∞
0
+
+
+
-
+
(
)
)
6.) Prvi izvod funkcije
(
)
(
)
y ′ = −2 x ⋅ x + 3 − x 2 ⋅ x = x ⋅ − x 2 − 2 x + 3 y′ = 0 x1 = −3
− x 2 − 2x + 3 = 0 ∧ x2 = 1
7.) Znak prvog izvoda
-∞
-3
x+ 3
+
x
1− x y′
1
0
+∞
+ +
+
+
-
+
+ + 0
-
y
8.) Grafik y 5,4
(1,2)
( )
2 x
5
y = 3− x ⋅
4 3 2 1 -3
-2 - -1 −6 − 3, 3
0 -2 -3 -4
2 101. y = ln x − 1
52
x 1
2
3
4
−6 3 y max (1) = 2 y min ( −3) =
1.) Domen D : x 2 − 1 > 0 x ∈ ( − ∞,−1) ∪ (1,+∞ ) . 2 2 2.) Parnost y ( − x ) = ln ( − x ) − 1 = ln x − 1 = y ( x ) Funkcija je parna.
3.) Periodičnost. Funkcija nije periodična. 4.) Nule funkcije x2 −1 = 1
y=0
x2 = 2
5.) Znak funkcije
-∞
x −1 x+1
x− 2
-
-
-1
1
-
+∞
+
- 0 + +
y
x1, 2 = ± 2
+
+ + - 0 + + +
-
-
+
6.) Prvi izvod funkcije y′ =
1 2x ⋅ 2x = 2 x −1 x −1 2
7.) Znak prvog izvoda y′ < 0
x < 0,
y↓
y′ > 0
x > 0,
y↑
8.) Grafik y
y = ln x 2 − 1 -2 - -1
53
0
12
x
x 2 − 2x + 1 x2 +1 1.) Domen D : ( ∀x ∈ R ) .
102. y =
2.) Parnost y ( − x )
( − x ) 2 − 2( − x ) + 1 x 2 + 2 x + 1 = = nije ni parna ni neparna. x2 +1 ( − x) 2
3.) Periodičnost.Nije periodična. 4.) Nule funkcije x 2 − 2x + 1 =0 x2 +1
y=0
( x − 1) 2 = 0
5.) Znak funkcije
0
1
( x − 1) 2
+
6.) Prvi izvod funkcije
0
+
x2 +1
y′ =
x1, 2 = 1 dvostruka nula.
+ +
+
y
+∞
0
+
( 2 x − 2) ⋅ ( x 2 + 1) − 2 x ⋅ ( x 2 − 2 x + 1) = 2 x 3 + 2 x − 2 x 2 − 2 − 2 x 3 + 4 x 2 − 2 x
( x + 1) 2 x − 2 2 ⋅ ( x − 1) 2 ⋅ ( x + 1) ⋅ ( x − 1) y′ = = = ( x + 1) ( x + 1) ( x + 1) 2
2
(x
2
2
2
)
+1
2
2
2
2
2
2
2
7.) Znak prvog izvoda
-∞
x− 1
-
x+1
( x y+′ 1) 2
-1
2
0
1
+
0
+ +
+
+
+
+
-
+
y min (1) = 0 y max ( −1) = 2
y
8.) Asimptote
lim x →∞
2
2
x − 2x + 1 / : x = lim x2 +1 / : x2 x →∞
2 1 + x x2 1 = = 1 horizontalna asimptota y=1. 1 1 1+ 2 x
1−
Kose i vertikalne asimptote ova funkcija nema.
54
9.) Grafik y
5 4
( − 1,2)
x 2 − 2 x +1 y= x 2 +1
3 2
(1,0)
1 -3
-2
-1
0
1
x 2
3
y=1
4
-2 -3 -4
103. y =
3
x +1 x2
1.) Domen D : x ≠ 0 .
( − x) 3 + 1 = − x3 + 1 nije ni parna ni neparna. x2 ( − x) 2
2.) Parnost y ( − x ) =
3.) Periodičnost. Nije periodična. 4.) Nule funkcije y=0 x = −1
x3 + 1 = 0
( x + 1) ( x 2 − x + 1) = 0
5.) Znak funkcije
-∞
x +1
+ + -
2
x − x +1 2
x
y
6.) Prvi izvod funkcije
(
-1
)
0
0
+ + + +
(
0
)
3 x 2 ⋅ x 2 − 2 x ⋅ x 3 + 1 3x 4 − 2 x 4 − 2 x x ⋅ x 3 − 2 x3 − 2 = = = x4 x4 x4 x3 y′ = 0 x3 − 2 = 0 x3 = 2 x=3 2 y′ =
(
)(
x 3 − 3 23 = x − 3 2 x 2 + x ⋅ 3 2 + 3 4
55
)
+∞
+ + + +
7.) Znak prvog izvoda -∞
0
x−3 2
+∞
+ +
x3 y′
0
+ + -
0
y min ( 3 2 ) =
+ + + +
3 3
y
8.) Asimptote k = lim x →∞
x3 + 1 1 1+ 3 3 2 x +1 x x = 1 =1 = lim 3 = lim x 1 1 x x →∞ x →∞
x3 + 1 x3 + 1 − x3 1 1 − x = = lim 2 = = 0 lim 2 2 ∞ x x x →∞ x →∞ x →∞ x y = kx + n y = x kosa asimptota.
n = lim
Horizontalne asimptote nema. x3 + 1 = lim lim x2 x →0 x →∞
9.) Grafik
1 x3 = 1 = 0 vertikalna asimptota je y – osa. 1 ∞ x y
1+
3 3 2, 3 4
x3 + 1 y= 2 x
1 -3
-2
-1
0 -1 -2
y=x
56
-3
1
2
x
4
≈2
104. y =
2x − 1
( x − 1) 2
1.) Domen D : x − 1 ≠ 0
x ≠1 2 ⋅ ( − x ) − 1 − ( 2 x + 1) = 2.) Parnost y ( − x ) = ( − x − 1) 2 ( x + 1) 2 nije ni parna ni neparna funkcija.
3.) Periodičnost. Nije periodična. 4.) Nule funkcije y=0
⇒
2x −1 = 0
x=
1 2
5.) Znak funkcije -∞
1
2x − 1 ( x − 1) 2
-
y
0
+∞
+
+
+
-
+
+ 0
+ +
6.) Prvi izvod funkcije y′ =
2( x − 1) 2 − 2( x − 1) ⋅ ( 2 x − 1)
( x − 1) 4 2 x ⋅ (1 − x ) y′ = ( x − 1) 4
7.) Znak prvog izvoda
( x − 1) 4
x=0
-∞
0
2x
+
1− x y′ 2x − 1
2x 2 − 4x + 2 − 4x 2 + 2x + 4x − 2
y′ = 0
( x − 1) 4
8.) Asimptote
=
0
∧
x = 1∉ D 1
+∞
+ +
0
+ +
+
+
0
-
-
+
y min ( 0 ) = − 1
-
y 2 −1
1 = +∞ − − 0+ 2x − 1 2 −1 1 = lim = + = +∞ vertikalna asimptota x = 1. lim 2 2 0 x →1+ ( x − 1) x →1+ (1 − 1) 2 1 − 2x − 1 2x − 1 0 x x2 = lim 2 = lim = = 0 horizontalna asimptota. lim 2 1 x →∞ ( x − 1) x →∞ x − 2 x + 1 x →∞ 1 − 2 + 1 x x2 = lim lim 2 2 x →1 ( x − 1) x →1 (1 − 1)
=
Kose asimptote ova funkcija nema. 57
9.) Grafik
y
y=
2x −1
( x − 1) 2
1 2 -3
-2
-1
1
0
( 0,−1)
2
x
-1 -2 -3 x= 1
-4
105.
( x − 2) 3 y= x2 +1
x ∈ ( − ∞,+∞ )
1.) Domen D := R
( − x − 2) 3 − ( x + 2) 3 = = funkcije nije ni parna ni neparna. x2 +1 ( − x) 2 + 1
2.) Parnost y ( − x )
3.) Periodičnost. Nije periodična. 4.) Nule funkcije y=0
x−2=0
x=2 -∞
5.) Znak funkcije
( x − 2) 2 x− 2 6.) Prvi izvod funkcije y′ =
(
)
x2 +1 y
3( x − 2 ) 2 ⋅ x 2 + 1 − 2 x ⋅ ( x − 2) 3
y′ = 0
(x
2
)
+1
x-2 = 0 x1 = 2
2
y′ =
58
x 3 = −3
( x − 2) 2 ⋅ ( x + 3) ⋅ ( x + 1)
(x
2
)
+1
2
+ + -
+∞
0 0
+ + + +
0
( x − 2) 2 [3 x 2 + 3 − 2 x 2 + 4 x ] ( x − 2 ) 2 ( x 2 + 4 x + 3) = =
x 2 + 4x + 3 = 0 x 2 + x 3 = −4 x 2 ⋅ x3 = 3
x 2 = −1
2
(x
2
)
+1
2
(x
2
)
+1
2
7.) Znak prvog izvoda -∞
( x − 2) 2 ( x + 1)
+
-1
+
2
+
0
+∞
+
y max ( −3) =
2
2
x+3 y′
8.) Asimptote
-3
- 0 + - 0 + 0 - 0
+ + + + + + + 0 +
y min ( −1)
( − 5) 3 10
( − 3) 3 = 2
=
− 125 10
=
− 27 2
y prev ( 2 ) = 0
y
( x − 2) 3
3
2 1 − 3 3 2 ( x − 2) / : x 1 x x + 1 k = lim = lim 3 = lim = =1 3 x 1 x →∞ x →∞ x + x / : x x →∞ 1 + 1 2 x 3 ( x − 2) x 3 − 6 x 2 + 12 x − 8 − x 3 − x − 6 x 2 + 11x − 8 = lim n = lim 2 − x = lim = x2 +1 x2 +1 x +1 x →∞ x →∞ x→∞ 11 8 −6+ − 2 −6 x x = lim = = −6 1 1 x →∞ 1+ 2 x ( x − 2) 3 y = x − 6 kosa asimptota funkcije y = . -1 0 6 1 x2 +1 x
Funkcija presijeca kosu asimptotu. y = x−6
( x − 2) 3 y= x2 +1
⇒
( x − 2) 3 − x − 6 = 0
( x − 2) 3 x2 +1
= x−6
x2 +1 x 3 − 6 x 2 + 12 x − 8 − x 3 − x + 6 x 2 + 6 =0 x2 +1 11x − 2 =0 x2 +1 11x − 2 = 0 2 1 x= ≈ 11 5
59
y
-7
-6
0
-5
9.) Grafik y
3 ( x − 2) y=
x2 + 1
( 2,0) -6
-5 -4
-3
-2
-1
0
( − 2,−1)
1 -1 -2 -3 -4 -5 -6 -7
( 0,−8)
-8 -9 -10
− 25 − 3, 2
-11
-12 -12,5 -13 27 -13,5 − 1,− 2
106. y = ( x − 1) ⋅ ln 2 ( x − 1) 1.) Domen D : x − 1 > 0 x > 1 x ∈ (1,+∞ ) 2.) Parnost. Nije ni parna ni neparna. 3.) Periodičnost. Nije periodična. 4.) Nule funkcije y = 0 x −1 = 1
60
x=2
2
3
4
5
6 y=x-6
x
5.) Znak funkcije
( ∀x ∈ D )
y>0
6.) Prvi izvod funkcije 2 ⋅ ln ( x − 1) x −1 y ′ = ln ( x − 1) ⋅ [ ln ( x − 1) + 2] y′ = 0 ln ( x − 1) = 0 ln ( x − 1) + 2 = 0 y ′ = 1 ⋅ ln 2 ( x − 1) + ( x − 1) ⋅
x − 1 = 0
ln ( x − 1) = −2
x −1 = 1
x - 1 = − 2 x = 1 + −2 1 x = 1+ 2
x=2
ln ( x − 1)
1
21ln+−x()
7.) Znak prvog izvoda
y′ 8.) Asimptote
= lim x →1+
+
2⋅
-
+∞
-
-
0
+
+
0
-
0
y
+
1 max 1+ 2
+ 0
+
y
( x − 1) ⋅ ln 2 ( x − 1) = lim lim x →1 x →1 +
2
x −1 ln ( x − 1) = lim = lim 1 1 x →1+ x →1+ 2 ( x − 1) ln ( x − 1) 2
2 ln ( x − 1) ⋅ − 1⋅
1
1 x −1 =
( x − 1) 2
1 x −1 = 2( x − 1) = 0 + lim 1 x →1+
( x − 1) 2
Vertikalna asimptota funkcije je x= 1. 9.) Grafik
y
5
y = ( x − 1) ⋅ ln 2 ( x − 1)
4 3
1 4 1+ 2 , 2 ( 1,0) (2,0)
2 1 0
61
1
2
3
x 4
=
1 ⋅4 2
107. y = ln
x−3 x+2
x−3 >0 x+2 D : x ∈ ( − ∞,−2 ) ∪ ( 3,+∞ )
1.) Domen ln x > 0
x+2<0
x < −2 x > 3
2.) Parnost. Nije ni parna ni neparna. 3.) Periodičnost. Nije periodična. 4.) Nule funkcije x−3 =1 x+2
⇒ x − 3 = x + 2 0 = 5 funkcija nema nula.
5.) Znak funkcije y>0 y<0
za x < −2 za x > 3
6.) Prvi izvod funkcije
′ ′ x − 3 1 x−3 x + 2 1 ⋅ ( x + 2) − 1 ⋅ ( x − 3) x+2− x+3 y ′ = ln ⋅ ⋅ = = = 2 x−3 x+ 2 x−3 ( x − 3) ⋅ ( x + 2) ( x + 2) x + 2 x+2 5 y′ = ( x − 3) ⋅ ( x + 2) y ′ > 0 ⇒ y raste ( ∀x ∈ D )
7.) Asimptote
x−3
−5 = ln + ∞ = +∞ 0 lim x → −2 x−3 0 ln = lim ln = ln 0 = −∞ lim x + 2 x→3 5 x →3 Vertikalne asimptote su x= -2 i x=3. ln = ln lim x + 2 lim x → −2 x → −2
x−3 x−3 /: x ln = lim ln = ln lim x + 2 x→∞ x + 2 / : x lim x →∞ x →∞
je y=0 , odnosno x- osa. 8.) Grafik
y = ln
3 x = ln 1 = 0 horizontalna asimptota 2 1+ x 1−
y
x−3 x+2
x y=0
62
-2
0
3
108. y = x ⋅ ln 2 x 1.) Domen D : x > 0 x ∈ ( 0,+∞ ) . 2.) Parnost y ( − x ) nije definisano. 3.) Periodičnost. Nije periodična. 4.) Nule funkcije y = 0 ⇒ x = 0 ∉ D ln 2 x = 0 ⇒ x = 1
5.) Znak funkcije
0
1
x
+
ln 2 x
+
0
6.) Prvi izvod funkcije
(
+ +
+
y
+∞
0
+
)
′ 1 y ′ = x ′ ⋅ ln 2 x + x ⋅ ln 2 x = ln 2 x + x ⋅ 2 ln x ⋅ = ln 2 x + 2 ln x = ln x ⋅ ( ln x + 2 ) x y ′ = 0 ln x = 0 ln x + 2 = 0 x =1 ln x = −2 x = − 2 1 1 x= 2 ≈ 8
7.) Znak prvog izvoda 0
ln x
ln x + 2 y′
1
+
=
1 1 ⋅ 4 ≈ 2 2
+
y
+
+
y min (1) = 1 ⋅ ln 2 1 = 0
-
+
0
+∞
0
1 max 2
y
8.) Asimptote 1 1 2 ln x ⋅ 2⋅ 2 ln x 2 ln x 2x 2 2 x = x = x ⋅ ln x = = = =0 lim lim lim lim lim lim −2 1 1 x x →0 x →0 x →0 1 ⋅ − x x →0 − x x→0 x →0 x x2 x2
(
63
)
9.) Grafik
y
5 4 3 2 1
y = x ⋅ ln 2 x
1 4 2, 2 ( 1,0) 0
1
x 2
3
4
x=0 2
109. y = sin x − sin x 1.) Domen D : R x ∈ ( − ∞,+∞ ) . 2.) Parnost y ( − x ) = ( sin ( − x ) ) 2 − sin ( − x ) = ( − sin x ) 2 + sin x = sin 2 x + sin x Nije parna ni neparna funkcija. y ( x + 2 kπ ) = ( sin ( x + 2kπ ) ) 2 − sin ( x + 2kπ ) = sin 2 x − sin x 3.) Periodičnost Periodična, sa periodom 2kπ . 4.) Nule funkcije sin 2 x − sin x = 0 sin x ⋅ ( sin x − 1) = 0
sin x = 0
∨
x = kπ
sin x = 1 π x = + 2kπ 2
5.) Znak funkcije
y = sin x ⋅ ( sin x − 1)
0
sin x sin x − 1 y
+ - 0 - 0
+ -
0 0
+
6.) Prvi izvod funkcije
y ′ = 2 sin x ⋅ cos x − cos x = cos x( 2 sin x − 1) 0 y′ = 0 cos x = 0 2 sin x − 1 = 0 π Ekstremi : x1 = π + 2kπ x 2 = +cos 2kxπ 2 6 2 + 1 1 1 1 1 5 y π = − = − = − min - Z0) 2 4 2 4x3 = 2πsin+ x2k−π1 ( k ∈ 2 6 6 y π = 1−1 = 0 y′
- 0
max 2
2 7.) Znak prvog 1 1 1 izvoda
y
64
y
5π min 6
3π max 2
= − =− 2 4 2 = ( − 1) 2 − ( − 1) = 1 + 1 = 2
y
+ 0 + + 0 + 0 -
0
-
+ -
+
-
-
8.) Grafik y
2
y = sin x − sin x
3π ,2 2
2
− 2π
−
3π 2
−π
π − 2
0
π ,0 2
π
π
π 1 2 ,− 6 4
5π 1 ,− 4 6
110. y = cos 2 x + cos x 1.) Domen D : R x ∈ ( − ∞,+∞ ) . 2.) Parnost y ( − x ) = ( cos( − x ) ) 2 + cos( − x ) = cos 2 x + cos x = y ( x ) .
3π 2
2π
3.) Periodičnost. y ( x + 2kπ ) = cos 2 ( x + 2kπ ) + cos( x + 2kπ ) = cos 2 x + cos x = y ( x ) Funkcija je periodična sa periodom 2kπ k = 0,±1,±2... 4.) Nule funkcije y = cos x( cos x + 1) = 0 cos x = 0 π x = ( 2k + 1) ⋅ , 2 (k ∈ Z)
cos x = −1 x = π + 2kπ
0
5.) Znak funkcije
cos x cos x + 1
65
y
+ 0 + + 0 + 0
- 0 +
- 0 -
0
+ + +
x
6.) Prvi izvod funkcije
y ′ = 2 cos x( − sin x ) + ( − sin x ) ⋅ 1 y ′ = − sin x( 2 cos x + 1) y′ = 0 sin x = 0 2 cos x + 1 = 0 x1 = kπ 2cosx = −1 cosx = −
1 2
2π + 2kπ 3 4π x3 = + 2kπ 3 x2 =
7.) Znak prvog izvoda
0
Ekstremi : 2
y
2π min 3
1 1 1 1 1 = − = − =− 2 4 2 4 2
− sin x
0 - 0 + 2 cos x + 1 + 0 - 0 y′
y max ( π ) = 1 − 1 = 0 2
y
4π min 3
- 0 + 0 -
0
+ + +
y
1 1 1 = − =− 2 4 2
y max ( 2π ) = ( − 1) 2 − ( − 1) = 1 + 1 = 2
8.) Grafik
y = cos 2 x + cos x
y
( 2π ,2)
( 0,2)
− 111. y = 66
3π 2
sin x 2 + cos x
−π
π ,0 2
−
π 2
0
π
3π 4π 1 2 2π 1 3 ,− 4 2 ,− 3 4 π
2π
5π 2
x
2 + cos x ≠ 0 cos x ≠ −2 ( ∀x ∈ R ) . sin ( − x ) − sin x sin x 2.) Parnost y ( − x ) = 2 + cos( − x ) = 2 + cos x = − 2 + cos x = −( y ( x ) ) .Neparna funkcija. 3.) Periodičnost. Periodična sa periodom 2kπ .
1.) Domen D :
4.) Nule funkcije y=0
5.) Znak funkcije
(k ∈ Z)
x = kπ
sin x = 0 0
sin x 2 + cos x
0
+ +
0
y
+
0
+
0
0
-
0
6.) Prvi izvod funkcije y′ =
cos x( 2 + cos x ) + sin x( sin x )
y′ = 0
( 2 + cos x )
2
2cosx + 1 = 0
=
2 cos x + cos 2 x + sin 2 x
( 2 + cos x )
cos x = − x1 =
2
2 cos x + 1
( 2 + cos x ) 2
1 2
2π + 2kπ 3
x2 =
7.) Znak prvog izvoda Ekstremi :
4π + 2kπ 3
0
3 3 3 2 y 2π = = 2 = 3 max 3 1 3 2 + − 2 2 1 1 − − 2 = 2 =− 1 ≈ 2 y 4π = min 3 4− 3 4− 3 5 3 2− 2 2 y ′′ =
=
2 cos x + 1
( 2 + cosyx′) 2
+ 0 +
- 0 +
+ +
+
-
+
0
0
y
− 2 sin x( 2 + cos x ) 2 + 2( 2 + cos x ) ⋅ sin x( 2 cos x + 1)
( 2 + cos x ) 4
( 2 + cos x )[ − 4 sin x − 2 sin x cos x + 4 sin x cos x + 2 sin x ] = 2 sin x cos x − 2 sin x = 2 sin x( cos x − 1) ( 2 + cos x ) 4 ( 2 + cos x ) 3 ( 2 + cos x ) 3 y sin x y ′′ = 0 sin x = 0 cos x = 1 y= 2 + cos x x = kπ x=0 x = 2π y ′′ =
Prevojne tačke 8.) Grafik
− 2π 67
−
−
4π 3
−π
2π 3 3 , 3
2π 3 0
π 2
2π 3
π
4π 3
4π 1 , 3 4− 3
2π
x
112. y = x 2 ⋅ (1 − ln x ) 1.) Domen D : x > 0 x ∈ ( 0,+∞ ) . 2.) Parnost. Nije ni parna ni neparna funkcija. 3.) Periodičnost. Funkcija nije periodična. 4.) Nule funkcije y=0
x2 = 0 ∉ D
∧
ln x = 0 ln x = 1 x = 1 =
5.) Znak funkcije
0
+∞
1− ln x
+
x2
+
y
+
6.) Prvi izvod funkcije
0
+
0
-
1 y ′ = 2 x ⋅ (1 − ln x ) + x 2 ⋅ − = 2 x(1 − ln x ) − x x y ′ = x ⋅ ( 2 − 2 ln x − 1) = x ⋅ (1 − 2 ln x ) y′ = 0 ⇒ x = 0 ∉ D ∧ 1 − 2 ln x = 0 2 ln x = 1 1 ln x = 2 x=
1 2
7.) Znak prvog izvoda
= 0
1− 2 ln x
+
x
+
y′
+
y
68
+∞
0
+
0
-
y max ( ) = 2
x xy−⋅=+20ln1[]() ′ ′ 1 xy−=2ln1 ′ xy−=1ln2 ′
− 2 ln x − 1 = 0 1 ln x = − 2
Prevojna tačka
−
x =
1 2
1
=
8.) Asimptote 1 1 − ln x − x −1 ⋅ x 3 x2 2 x x ⋅ (1 − ln x ) = lim = lim = lim = lim =0 lim −3 1 2 x →0 x →0 x →0 − 2 x x →0 x →0 2 x2 −
9.) Grafik
y = x 2 ⋅ ( 1 − ln x )
y
5 4 3
, 2
2 1
x 0 1 1
113. y =
x +1 x+2
1.) Domen D :
x+2≠0
2
3
4
x ≠ −2
− x +1
1− x 1− x = =− 2.) Parnost y ( − x ) = nije ni parna ni neparna funkcija. − x + 2 − ( x − 2) x−2
3.) Periodičnost. Nije periodična. 4.) Nule funkcije. Nema nula. 5.) Znak funkcije
-∞
x+2 y
69
-2
-
0
+∞
+
+
+
-
+
6.) Prvi izvod funkcije y′ =
( )′ x +1
( x + 2) ′
y′ = 0
=
( x + 2) 2
x +1 = 0
x = −1
7.) Znak prvog izvoda -∞
( )=
x +1 ⋅( x + 2 ) − 1 ⋅ x +1
-2
(
x +1
≠ 0,
-1
x+1
+ -
+ -
( x + 2) 2
+
+
+
-
+
-
y′
x +1 > 0
)
+∞
x +1
0
( x + 2 − 1) = x+1 ( x + 1) ( x + 2) 2 ( x + 2) 2
x +1
+ +
1 y min ( −1) = = 1 1
y
( x + 2) 2 ⋅ (x+1 ⋅ ( x + 1) + x+1 ) − 2( x + 2) x+1 ⋅ ( x + 1) ( x + 1) 4 ( x + 2) ⋅ (x+1 ) ⋅ [ x 2 + x + 2 x + 2 + x + 2 − 2 x − 2] = x+1 ⋅ ( x 2 + 2 x + 2) y ′′ = ( x + 2) 4 ( x + 2) 3 y ′′ =
y ′′ > 0
Funkcija ima minimum. 8.) Asimptote
lim y = lim x → −∞
x →−∞
x +1 L. P
lim x → +∞ x + 2
=
x +1 L.P x +1 1 1 = lim = lim −( x +1) = = 0 horizontalna asimptota. x + 2 x→−∞ 1 ∞ x →−∞
x +1 ∞ = =∞ lim 1 x →+∞ 1
x +1 −1 1 1 = = = = −∞ lim − 0 ⋅ ( − 0) − 0 x → −2 − 0 x + 2 x +1 −1 1 1 = = = = +∞ lim + 0 ⋅ ( + 0) + 0 x → −2 + 0 x + 2
70
9.) Grafik
y
( − 1,1) -3
-2
x +1 y= x+2
1 -1
0 -1
1
2
x
y=0
-2 -3 x= - 2
114. y =
( x − 2) 3
x2 + x +1 1.) Domen D := R
2.) Parnost y ( − x ) =
x ∈ ( − ∞,+∞ )
( − x − 2) 3 = − ( x + 2) 3 funkcije nije ni parna ni neparna. ( − x) 2 − x + 1 x 2 − x + 1
3.) Periodičnost. Nije periodična. 4.) Nule funkcije y=0
x−2=0
x=2
5.) Znak funkcije
-∞
( x − 2) 3 x2 + x +1
6.) Prvi izvod funkcije y′ = y′ =
71
(
)
y
2
+ +
2
( x − 2 ) 2 ( x 2 + 6 x + 5)
(x
2
)
+ x +1
2
)
+ x +1
2
+ +
-
3( x − 2 ) 2 ⋅ x 2 + x + 1 − ( 2 x + 1) ⋅ ( x − 2 ) 3
(x
0
+∞
0 =
+
( x − 2 ) 2 [3 x 2 + 3 x + 3 − 2 x 2 + 4 x − x + 2 ]
(x
2
)
+ x +1
2
y′ = 0
x 2 + 6x + 5 = 0 x 2 + x 3 = −6
x-2 = 0 x1 = 2
x 2 ⋅ x3 = 5 x 2 = −1 y′ =
x 3 = −5
( x − 2) 2 ⋅ ( x + 5) ⋅ ( x + 1)
(x
2
)
+1
2
7.) Znak prvog izvoda
-∞
( x − 2) 2 ( x + x + 1) 2
2
x+5 y′
-5
+
-1
+
- 0 + - 0 + 0 - 0
2
+
+∞
0
+
y max ( −5 ) =
+ + + + + + + 0 +
y min ( −1)
− 343 21
( − 3) 3 = 1
= −27
y prev ( 2 ) = 0
y
8.) Asimptote
( x − 2) 3
3
2 1 − 3 3 2 ( x − 2) / : x x = 1 =1 x + x + 1 k = lim = lim 3 = lim 2 3 x 1 x →∞ x →∞ x + x + x / : x x →∞ 1 + 1 + 1 2 x x 3 3 2 3 ( x − 2) x − 6 x + 12 x − 8 − x − x 2 − x − 7 x 2 + 11x − 8 = lim n = lim 2 − x = lim = 2 2 x + x + 1 x + x + 1 x + x + 1 x →∞ x → ∞ x → ∞ 11 8 −7+ − 2 −7 x x = lim = = −7 1 x →∞ 1 + 1 + 1 x x2 ( x − 2) 3 y = x − 7 kosa asimptota funkcije y = . x -1 0 6 1 x2 + x +1
Funkcija presijeca kosu asimptotu.
y = x−7 y=
( x − 2) 3 x2 + x +1
( x − 2) 3
⇒
( x − 2) 3 x2 + x +1
− x−7 = 0 ⇒ x2 + x +1 18 x − 1 =0 18 x − 1 = 0 x2 + x +1
y
= x−7 x 3 − 6 x 2 + 12 x − 8 − x 3 + 6 x + 6 x 2 + 7 =0 x2 +1 1 x= 18
1 ,−7 tačka presjeka kose asimptote i funkcije. 18
72
-8
-7
-1
-6
9.) Grafik
y
y=
-5
-1
( 2,0)
0
( x − 2) 3 x2 + x + 1
( 7 ,0 )
y=x-7
x
( 0,− 8) − 343 − 5, 21
x 115. y = x +1
1.) Domen D : 2.) Parnost y ( − x ) =
( − 1−, 27) x +1 ≠ 0
-27
x ≠ −1
−x
− x − x = =− nije ni parna ni neparna funkcija. − x + 1 − ( x − 1) x −1
3.) Periodičnost. Nije periodična. 4.) Nule funkcije. Nema nula.
73
-16
-∞
5.) Znak funkcije
-1
x +1
-
x
+
+
-
+
y
6.) Prvi izvod funkcije y′ =
( )′ x
( x + 1) ′
y′ = 0
=
0
( ) = ( x + 1 − 1) =
x ⋅( x + 1) − 1 ⋅ x
( x + 1) 2
x ⋅ x = 0
+∞
x=0
x
( x + 1) 2
+
x ⋅ x
( x + 1) 2
x = 0 y =1
7.) Znak prvog izvoda -∞
-1
0
+∞
x
x
+ -
( x + 1) 2
+ -
+ 0
0
+ +
+
+
+
-
1 y min ( 0 ) = = 1 1
y
Funkcija ima minimum. 8.) Asimptote
lim y = lim x → −∞
x →−∞
x L. P x 1 1 = lim = −∞ = ∞ = = 0 horizontalna asimptota. x + 1 x→−∞ 1 ∞
L. P x ∞ = lim = =∞ lim 1 x → +∞ x + 1 x → +∞ 1 x
x −1 1 1 = = = = −∞ lim − 0 ⋅ ( − 0) − 0 x →−1− 0 x + 1 x −1 1 1 = = = = +∞ lim + 0 ⋅ ( + 0) + 0 x →−1+ 0 x + 1
74
9.) Grafik y
x y= x +1 ( 0,1) -3
-2
-1
1 0
1 -1 -2 -3
x= - 1
Integrali
∫ f ( x ) = F( x ) + C F( ′x ) = f ( x )
Osnovni tablični integrali x n+1 +C n +1 ∫ sin xdx = − cos x + C n ∫ x dx =
∫ cos xdx = sin x + C x x ∫ dx = + C dx ∫ sin 2 x = −ctgx + C dx
∫ cos 2 x = tgx + C x ∫ a dx =
dx
∫ 1− x2
= arcsin x + C
∫ 1+ x2
= arctgx + C
dx
∫ 75
ax +C ln a
dx = ln x + C x
2
x
y=0
116.
∫ (x
3
)
+ 2 x 2 − x − x dx = ∫ x 3 dx + 2∫ x 2 dx − ∫ xdx − ∫ x dx =
x4 x3 x 2 2 x3 +2 − − +C 4 3 2 3
117. x−3= t ( x − 3) 16 dx = = ∫ 3 t 16 dt = ∫ dx = dt
∫3
16 t 3 dt
=
16 +1 t3
19
16 +1 3
( x − 3) 3 +C = 19 3
3 3 ⋅ ( x − 3) 19 + C 19
+C =
118. x −3= t 2 1 x x ∫ sin 2 − 3dx = 2 dx = dt = 2∫ sin tdt = 2 ⋅ ( − cos t ) + C = −2 ⋅ cos 2 − 3 + C dx = 2dt
119. dx
∫ ( 2 x − 5) 3
dt 2x − 5 = t 1 1 1 −1 = 2dx = dt = ∫ 23 = ∫ t −3 dt = ⋅ − 2 + C = +C 2 2 2t t 4 ⋅ ( 2 x − 5) 2 1 dx = dt 2
120.
1 1 1 A B C D Ex + F = 2 2 = 2 = + 2 + + + 2 = 4 2 2 x x x −1 x +1 x +1 x x − 1 x x − 1 x + 1 x ( x − 1)( x + 1) x + 1
)( ) Ax ( x − 1) + B ( x − 1) + Cx ( x + 1) ( x = 2
(
)
4
=
(
4
2
(
(
)
)
(
)
(
)
+ 1 + Dx 2 ( x − 1) x 2 + 1 + ( Ex + F ) x 2 x 2 − 1 = x 2 ( x − 1)( x + 1) x 2 + 1
)(
2
) (
(
)
)(
)
Ax 5 − Ax + Bx 4 − B + Cx 3 + Cx 2 x 2 + 1 + Dx 3 − Dx 2 x 2 + 1 + Ex 5 − Ex 3 + Fx 4 − Fx 2 = x 2 ( x − 1)( x + 1) x 2 + 1
(
)
x 5 ( A + C + D + E ) + x 4 ( B + C − D + F ) + x 3 ( C + D − E ) + x 2 ( C − D − F ) + x ( − A) − B x 2 ( x − 1)( x + 1) x 2 + 1 − B = 1 (1) − A = 0 ( 2) C − D − F = 0 ( 3) C + D − E = 0 ( 4) B + C − D + F = 0 ( 5) A + C + D + E = 0 ( 6) =
A=0 B = −1
(
( 3) − ( 5)
⇒
− B − 2F = 0 - 2 F = -1
76
)
⇒F=
1 2
( 4) − ( 6)
C + D-E = 0 − A−C − D− E = 0 − A − 2E = 0 − 2E = 0 E=0 ( 3) + ( 4) ⇒ 2C − F − E = 0 1 2C = + 0 2 1 C= 4 ( 4) ⇒ D = E −C 1 D=− 4 1 1 1 1 − 2 + − + = 2 4( x − 1) 4( x + 1) 2 x + 1 x = =
⇒
(
)
(
(
)
)
(
)
(
2
2
(
)
4 x ( x − 1)( x + 1) x + 1 2
2
− 4x 4 + 4 + x5 + x3 + x 4 + x 2 − x5 + x 4 − x3 + x 2 + 2x 4 − 2x 2 4 = 2 4 2 4 4x x − 1 4x x − 1
(
)
(
1 dx 1 1 1 ∫ x 2 x 4 − 1 = ∫ − x 2 + 4( x − 1) − 4( x + 1) + 2 x 2 + 1 1 1 x −1 1 = + ln + arctgx + C x 4 x +1 2 dx 121. ∫ 2 = arctgx + C x +1
(
)
(
)
dx
∫ x2 + x +1 = ∫
dx 2
1 3 x + + 2 4
4 3 2 3 ⋅ ⋅ arctgt + C = arctg 3 2 3
122. 77
=∫
∫1+
xdx 1+ x
dx 2 1 x + 3 2 ⋅ 4 3 2
1 2 3 2
x+
3 dt 1 4 = dx = dt = ∫ 22 = 3 t +1 3 2 + 1 3 dt dx = 2
1 2 + C = 2 ⋅ arctg 2 x + 1 + C 3 3 3 2
x+
)
x − 2+1 1 1 1 dx = − + ln x − 1 − ln x + 1 + arctgx + C = − 2 + 1 4 4 2
t=
=
)=
− 1 ⋅ 4 ⋅ x − 1 + 1 ⋅ x ⋅ x + 1 ( x + 1) − 1 ⋅ x 2 ⋅ x 2 + 1 ( x − 1) + 2 x 2 x 2 − 1 4
∫1+
xdx
⋅
1− 1+ x
1+ x 1− 1+ x
= ∫ t dt = ∫
1 t 2 dt
=
=∫
1 +1 t2
1 +1 2
=
(
)
(
)
(
)
1+ x = t x ⋅ 1− 1+ x = −1∫ 1 − 1 + x dx = ∫ 1 + x − 1 dx = = dx = dt 1−1+ x 3 t2
3 2
=
2 ⋅ 3
(1 + x ) 3 − x + C
123. 1− x = t 1− x = t2 dx − 2tdt dt 1 ∫ (1 + x ) 1 − x = − dx = 2tdt = ∫ 2 − t 2 t = −2∫ 2 − t 2 = − 2 2 2 dx = −2tdt
(
)
dt
∫
2 −t
+
1 2
∫ 2
1− t2 = x 2
=
2 2
⋅ ln 2 − t −
1 = 2 −t2
2 2 2
1
(
2 −t
)(
2 +t
)
⋅ ln 2 + t = =
A 2 −t
+
1 2
2 −t
ln
B 2 +t
2 +t =
+C =
(
A 2 + At + 2 B − Bt t ( A − B ) + 2 A + 2 B = 2 −t2 2 −t2 A− B = 0 /⋅ 2 2 A + 2B = 1
2 2A = 1
B=
∫
78
1 2 2
=
2 4
2 4
2−x=t − dt = − dx = dt = ∫ = − ln t = − ln 2 − x t 2−x dx = − dt dx
2
) (
2 − 1− x
⋅ ln
)
2 + 1− x
A 2 +t + B 2 −t = 2 −t2
=
A=
1
+C
= 2 +t dt
124. x +1 = t6
xdx
∫ 3 x +1 − =∫
x +1
= dx = 6t 5 dt = ∫ x = t 6 −1
(
(t 3
)
6
− 1 6t 5 dt
t6 − t6
)
=∫
(
)
(
)
6t 3 ( t − 1) t 5 + t 4 + t 3 + t 2 + t + 1 dt = −6∫ t 8 + t 7 + t 6 + t 5 + t 4 + t 3 dt = − ( t − 1)
= −6
(
)
t9 t8 t7 t6 t5 t4 −6 −6 −6 −6 −6 +C = 9 8 7 6 5 4
− 26 ( x + 1) 9 36 ( x + 1) 8 66 ( x + 1) 7 66 ( x + 1) 5 36 ( x + 1) 4 = − − − ( x + 1) − − = 3 4 7 5 2 2 ( x + 1) 3 − 3 3 ( x + 1) 4 − 6 ( x + 1) 6 x + 1 − x − 1 − 6 6 ( x + 1) 5 − 3 3 ( x + 1) 2 + C =− 3 4 7 5 2
125. x4 1 1 = 1 + = 1 + = x4 −1 x2 −1 x2 +1 ( x − 1)( x + 1) x 2 + 1 = = =
(
(
)
)(
)
(
(
)
)
A( x + 1) x 2 − 1 + B( x − 1) x 2 + 1 + ( Cx + D )( x + 1)( x − 1) = ( x − 1)( x + 1) x 2 + 1
(
A x3 + x + x 2
(
) + 1) + B ( x + x − x − 1) + Cx ( x − 1)( x + 1) ( x + 1) 3
2
3
− Cx + Dx 2 − D
2
)
x 3 ( A + B + C ) + x 2 ( A − B + D ) + x( A + B − C ) + A + B − D = x4 −1 A + B + C = 0 (1) A − B + D = 0 ( 2) A + B − C = 0 ( 3) A − B − D = 1 ( 4)
=
(
(1) − ( 3)
2C = 0
( 2) − ( 4)
D + D = −1
(1) − ( 4)
)
⇒ C=0 D=−
2 B + C + D = −1 1 2 B = −1 + ⇒ 2 1 A+ B +C = 0 ⇒ A− +0 = 0 4
79
=
Ax 3 + Ax + Ax 2 + A + Bx 3 + Bx − Bx 2 − B + Cx 3 − Cx + Dx 2 − D = x4 −1
(
1 2 1 4 1 ⇒ A= 4 B=−
(
)
6t 5 t 6 − 1 dt 6t 5 t 6 − 1 dt 6t 3 t 6 − 1 = = ∫ t 2 (1 − t ) ∫ (1 − t ) = t2 − t3
1 1 1 1 1 1 = 1 + 4 − 4 − 22 = 1 + − − 2 x −1 x +1 x +1 4( x − 1) 4( x + 1) 2 x + 1 dx ∫ x ± a = ln x ± a + C a = const. x4 1 1 1 1 1 1 ∫ x 4 − 1 dx = ∫ 1 + 4( x − 1) − 4( x + 1) − 2 x 2 + 1 dx = x + 4 ln x − 1 − 4 ln x + 1 − 2 arctgx + C =
(
(
)
)
1 x −1 1 = x + ln − arctgx + C 4 x +1 2
126. x +1
x( x − 1) 3 = = =
(
A B C D A( x − 1) 3 + Bx( x − 1) 2 + Cx ( x − 1) + Dx = + + + = = x ( x − 1) ( x − 1) 2 ( x − 1) 3 x( x − 1) 3
)
(
)
A x 3 − 3x 2 + 3 x − 1 + Bx x 2 − 2 x + 1 + Cx 2 − Cx + Dx x( x − 1)
3
=
Ax 3 − 3 Ax 2 + 3 Ax − A + Bx 3 − 2 Bx 2 + Bx + Cx 2 − Cx + Dx x( x − 1) 3
=
x 3 ( A + B ) + x 2 ( C − 3 A − 2 B ) + x( 3 A + B − C + D ) − A x( x − 1) 3
A+ B = 0 C − 3 A − 2B = 0 3A + B − C + D = 1 − A =1 A = −1 B =1 C +3−2 = 0 C = −1 − 3 +1+1+ D = 1 D=2 A B C D 1 1 1 1 = + + + = − + − + x x − 1 ( x − 1) 2 ( x − 1) 3 x x − 1 ( x − 1) 2 ( x − 1) 3 x +1 1 1 1 dx ∫ x( x − 1) 3 dx = ∫ − x dx + ∫ x − 1 dx − ∫ ( x − 1) 2 dx + ∫ ( x − 1) 3 = dx
=
∫ ( x − 1) 2 dx
∫ ( x − 1) 3
x −1 = t dt t − 2+1 1 1 −2 = = = t dt = =− =− +C ∫ ∫ 2 − 2 +1 t x −1 t dx = dt = x −1 = t dt t −3+1 t −2 1 −1 −3 = +C = ∫ 3 = ∫ t dt = − 3 + 1 = − 2 = − 2 = t t 2( x − 1) 2 dx = dt
= − ln x + ln x − 1 +
80
1 1 x − 1 2( x − 1) − 1 x −1 2x − 3 − + C = ln + + C = ln + +C 2 2 x − 1 2( x − 1) x x 2( x − 1) 2( x − 1) 2
127.
∫
(1 − x ) 2 dx = x⋅ x
3 − +1 x 2
=
−
3 +1 2
−2
∫
1 − 2x + x 2 3 x2
1 − +1 x 2
−
1 +1 2
1 2x x 2 dx = ∫ 3 − 3 + 3 2 x2 x2 x
1 x2
+
1 +1 2
=
x
−
−
1 2
1 2
− 2⋅
1 x2
1 2
+
3 x2
3 2
1 1 −3 − 2 2 2 dx = ∫ x − 2 ⋅ x + x dx = 2
+C = −
x
−4 x +
2 3 x +C 3
128.
∫
(x
2
)
(
2
)
1 x2
−1 x x x −1 ⋅ dx = ∫ 2 x x2 3
+1
5 − +1
1 ⋅ x4
dx = ∫ 7
(x
2
)
−1 x2 −
3 x4
dx = ∫
11 x4
− x2
3 11 x 4 x4 dx = ∫ 2 − 2 dx = x x
3 x4
1
5 3 − x4 x 4 x4 x 4 4 4 7 4 = ∫ x 4 − x 4 dx = − +C = − = ⋅ x + 4 +C 3 5 7 1 7 x +1 − +1 − 4 4 4 4 2 x +3 4 129. ∫ 2 dx = ∫ 1 + 2 dx x −1 x −1 4 4 A B A( x + 1) + B ( x − 1) Ax + A + Bx − B x( A + B ) + A − B = = + = = = 2 x − 1 ( x − 1)( x + 1) x − 1 x + 1 x2 −1 x2 −1 x2 −1 A− B = 4 A+ B = 0 2A = 4 A=2 B = −2 x2 + 3 2 2 x −1 ∫ x 2 − 1 dx = ∫ 1 + x − 1 − x + 1 dx = x + 2 ln x − 1 − 2 ln x + 1 + C = x + 2 ln x + 1 + C
130.
∫ =∫
81
1+ x2 1 − x 2 1+ x2 dx = ∫ + dx = ∫ + 2 2 4 1− x4 1 + x 1 − x 1− x dx = arcsin x + ln x + x 2 + 1 + C 2 1+ x
1+ x2 + 1− x2 1− x4 dx 1− x
2
+∫
(
)(
)
1− x2 1+ x2 1− x2
(
)(
)
dx =
131. x2 +1 = t − x /2
(
)
2t ⋅ 2t − 2 t 2 − 1 t 2 +1 dx = dt x + 1 = t − 2tx + x dx dx 4t 2 2t 2 2 = = = = 1− t ∫ x 2 + 1 ∫ 2t 2 − t 2 + 1 dt = 2t 2 + 2 t2 +1 x2 +1 x = dx = dt = dt 2t 2t 4t 2 2t 2 t = x + x2 +1 2
∫
=∫
(
)
2
2
2t t 2 + 1 dt dt = = ln t + C = ln x + x 2 + 1 + C ∫ 2 2 t 2t t + 1
132.
(
)
x 2 + 2x + 3 = x + t / 2 x 2 + 2 x + 3 = x 2 + 2 xt + t 2 2 x − 2 xt = t 2 − 3 x( 2 − 2t ) = t 2 − 3
− t 2 + 2t − 3
t2 − 3 2(1 − t ) 2 =∫ 2 dt = ∫ x x 2 + 2 x + 3 = x = 2 − 2t t −3 t2 −3 ⋅ +t 2t ( 2 − 2t ) + 2 t 2 − 3 2 − 2t 2 − 2t dx = dt ( 2 − 2t ) 2 dx
(
dx = dx = dx =
4t − 4t 2 + 2t 2 − 6
( 2 − 2t ) 2
− 2t 2 + 4t − 6
(
( 2 − 2t ) 2
dt
dt
) dt
2 − t 2 + 2t − 3 2 2 (1 − t )
2
− t 2 + 2t − 3
=∫
)
(
)
2 − t 2 + 2t − 3 dt 2(1 − t ) 2 dt = ∫ 2 dt = 2 ∫ = 2 2 2 2 t − 3 t − 3 + 2t − 2t t − 3 − t + 2t − 3 t− 3 t+ 3 ⋅ 2(1 − t ) 2(1 − t )
(
)(
)
(
1 1 2 2 2 3 2 3 = 2∫ − dt = ln t − 3 − ln t + 3 + C = t − 3 t + 3 2 3 2 3 =
82
1 3
⋅ ln
x 2 + 2x + 3 − x − 3 2
x + 2x + 3 − x + 3
+C
)(
)
1 A B At + A 3 + Bt − B 3 t ( A + B ) + A 3 − B 3 = + = = t −3 t − 3 t + 3 t− 3 t+ 3 t− 3 t+ 3
(
2
A+ B = 0
)(
)
(
)(
)
/⋅ 3
A 3 − B 3 =1 2 3A = 1 1 A= 2 3
⇒
B=−
1 2 3
133.
∫ 3
x 5 − = t 3 −5 2 +1 − 5 3 − dx 1 − 3dt t t 3 9 = − dx = dt = ∫ = −3∫ t 3 dt = −3 ⋅ + C = 3⋅ +C = +C 3 5 5 2 5 2 3 t x x − +1 23 5 − 5 − dx = −3dt 3 3 3 3
134.
∫
dx 3 − 5x 2
x
=
3 5 1 3 5
dx 5x 2 31 − 3
=∫
dx 5x 2 3 1− 3
=∫
dx 3 1−
=
x2 3 5
1
dx
∫ 3
x 1− 3 5
2
2
=
=t 3 dx = dt =
dx =
83
=∫
3 dt 5
1
∫ 3
5
dt
1− t2
=
1 3
⋅
3 5
⋅∫
dt 1− t2
=
1 5
arcsin t + C =
1 5
arcsin
5x 3
+C
135. x
dx
∫
7 − 11x 2
1
=
7
⋅∫
=∫
dx 11 71 − x 2 7
7 ⋅ 1−
=
x2 7 11
1 7
dx
⋅∫
x 1− 7 11
2
∫3
=∫
(
(1 − 2 sin
2
)
x + sin 4 x cos xdx 8
( sin x ) 3
8 − +1 t 3
8 − +1 3
)
(
2
)
7 11 dx =
dx = dt =
7 dt 11
2
− 2⋅
2 − +1 t 3
2 − +1 3
+
4 +1 t3
4 +1 3
8 2 4 8 8 −8 − − 2− 4− 3 3 3 = ∫ sin x − 2 ⋅ ( sin x ) 3 + ( sin x ) 3 ⋅ cos xdx = ∫ t − 2t + t 3 dt =
+C =
t
−
5 3
5 − 3
− 2⋅
1 t3
1 3
+
7 t3
7 3
+C = −
(
3
∫
∫
2 x − 53 x +
3
5
2 dx dx = ∫ 3 2 x dx − 5∫ 3 x dx + 2 ∫ = 5 4x 4 x
2x 3 =t 2 2x x 2 3 3 3 2x 3 dx = ∫ dx = dx = dt = ∫ t dt = ⋅ 3 = 3 2 x 3 2 2 2 3 dx = dt 2
3 x = t 1 t 1 t 1 3x 3x t dt ∫ dx = 3dx = dt = ∫ 3 = 3 ∫ dt = 3 = 3 1 dx = dt 3
3 5
53 sin x
137.
84
=
sin x = t cos 2 x ⋅ cos xdx 1 − sin 2 x ⋅ cos xdx dx = =∫ = = ∫ 8 8 8 cos xdx = dt sin x ( sin x ) 3 ( sin x ) 3
cos 5 x
=
2
=t
7 dt dt 1 1 x 1 11x 11 = 1 ⋅ = arcsin t + C = arcsin +C = arcsin +C ∫ 2 2 11 11 11 7 11 7 1− t 1− t 11
136.
=
dx
=∫
7 11 1
)
− 63 sin x +
33 sin 7 x + C 7
4x − 5 = t 4x 4 − dx dx 4 5 5 5 −5x t t 5 ∫ 5 4 x = ∫ 4 x = ∫ dx = − 5 dx = dt = ∫ ⋅ − 4 dt = − 4 ⋅ ∫ dt = − 4 = 5 dx = − 5 dt 4 3 3 2x 1 3x 5 1 3 ⋅ 3 2 x 5 3 x 5 1 = ⋅ − 5⋅ ⋅ + 2⋅− ⋅ +C = − − ⋅ +C 5 5 2 3 4 4 x 2 3 2 4 x
138. x +1 =t x x − 1( x + 1) dx = dt x2 1 − 2 dx = dt x 1 2 x +1 dt 2 2 dx = − x dt dx = = ∫ ( t − 1) t − 2 x ( t − 1) x + 1 = xt x(1 − t ) = −1 1 x= ( t − 1) 1 x2 = ( t − 1) 2
1 ∫ x2
= −∫
1 t 2 dt
1 +1 t2
Parcijalna integracija
( u ⋅ v ) ′ = u ′ ⋅ v + u ⋅ v′ d ( u ⋅ v ) = v ⋅ du + u ⋅ dv
∫ u ⋅ dv = u ⋅ v − ∫ v ⋅ du
′ ∫ d ( u ⋅ v ) = ∫ v ⋅ du + ∫ u ⋅ dv
( u ⋅ v ) − ∫ v ⋅ du = ∫ u ⋅ dv
139.
x=u
∫ x ⋅ dx = dx = du x
x dx = dv v = ∫ dx = x
x
= x ⋅ x − ∫ x dx = xx − x + C = x ⋅ ( x − 1) + C
140. ln x = u ∫ ln xdx = 1 dx = du x
85
dx = dv x=v
3
2 x + 1 =− =− +C 1 3 x +1 2
1 = x ⋅ ln x − ∫ x ⋅ ⋅ dx = x ⋅ ln x − x + C = x ⋅ ( ln x − 1) + C x
2 141. ∫ sin xdx I način :
∫ sin
2
xdx = ∫ sin x ⋅ sin x ⋅ dx =
sin x = u cos xdx = du
sin xdx = dv = I = sin 2 x = - cos x = v
(
)
= − sin x cos x + ∫ cos 2 xdx = − sin x cos x + ∫ 1 − sin 2 x dx = − sin x cos x + x − ∫ sin 2 xdx = I = − sin x cos x + x − I 2 I = x − sin x cos x x − sin x cos x I= +C 2
II način : sin 2 x + cos 2 x = 1 cos 2 x − sin 2 x = cos 2 x 2 sin 2 x = 1 − cos 2 x 1 − cos 2 x sin 2 x = 2 1 − cos 2 x 1 1 2 ∫ sin xdx = ∫ 2 dx = ∫ 2 − 2 ⋅ cos 2 x dx = 2 x = t 1 1 1 1 1 1 1 1 = ∫ cos 2 xdx = 2dx = dt = ∫ cos tdt = sin t = sin 2 x = x − ⋅ sin 2 x + C = x − sin 2 x + C 2 2 2 2 2 2 2 4 1 dx = dt 2
142.
∫
ln x = u
ln xdx = 1 x2 dx = du x
=−
1 dx = dv 1 1 − ln x x2 = − ⋅ ln x + ∫ 2 dx = + ∫ x − 2 dx = x x 1 x − =v x
ln x x −2+1 − ln x − 1 + +C = +C x − 2 +1 x
143. 2 ∫ x arctgxdx =
86
arctgx = u 1 dx = du 1+ x2
x 2 dx = dv 3
x =v 3
=
x3 1 x3 ⋅ arctgx − ∫ dx = 3 3 1+ x2
x2 + 1 = t x3 x x2 xdx ∫ 1 + x 2 dx = ∫ x − 1 + x 2 dx = 2 − ∫ x 2 + 1 = 2 xdx = dt = 3 2 dt = x arctgx − 1 ⋅ x − 1 ln x 2 + 1 + C xdx = 3 3 2 2 2 dt x2 x2 1 x2 1 = −∫ 2 = − ln t = − ln x 2 + 1 2 t 2 2 2 2
(
)
144.
dx
x
x
x
∫ sin x = sin x = 2 sin 2 cos 2 = 2tg 2 ⋅ cos
2
x = 2
2tg 1 cos 2
= cos x = cos 2
x x − sin 2 2 2
x 2 = x 2
2tg
x 2
x x sin + cos 2 2 2 x cos 2 2 2
x 1 − tg 2 cos x 2 x 2 x 2 = ⋅ = 1 − tg = ⋅ cos 1 cos x 2 2 1 + tg 2 x cos 2 2 1 − tg 2
t = tg
=
2tg
x 2
x tg +1 2 2
x 2 = x 2
x 2
x 2dt 2 2 sin x dt x = tgx = = = x = 2arctgt = ∫ 1+t = ∫ = ln t + C = ln tg + C x 2t cos x t 2 1 − tg 2 1 2 2 dx = 2 ⋅ dt 1+t 1+ t2 2t sin x = 1+ t2 x 2tg 2
87
arctgt =
=
145.
cos x =
1− t2 1+ t2
1 − t 2 2dt ⋅ 2 2 1 + t 1 + t 2 = 1 − t =∫ ∫ 1 + t 2 1 + t 2 2 1+ t2
x cos xdx 2 ∫ 1 + cos x = 2dt dx = 1+ t2 t = tg
1 + cos x = 1 +
dt =
1− t2 1+ t2 +1− t2 2 = = 2 2 1+ t 1+ t 1+ t2
1 x x x x = arctgt − ∫ 1 − 2 dt = arctgt − t + arctgt + C = 2arctg tg − tg + C = 2 ⋅ − tg + C = 2 2 2 t + 1 2 x = x − tg + C 2
146.
x x x x sin x = 2 sin cos = 2tg ⋅ cos 2 = 2 2 2 2
dx 2 x 2 x ∫ 3 + 5 cos x = cos x = cos 2 − sin 2
t = tg
x 2
x 2 x = 2arctgt 1 dx = 2 ⋅ dt 1+t2 2t sin x = 1+t2 1−t2 cos x = 1+t2 arctgt =
88
2tg 1
x 2 =
x cos 2 2
2tg sin 2
x 2
x x + cos 2 2 2 2 x cos 2
cos x x x ⋅ = 1 − tg 2 ⋅ cos 2 = cos x 2 2
2tg = tg 2
x +1 2
x 1 − tg 2 2 = 1 1 + tg 2 x cos 2 2
1 − tg 2
x 2
x 2 x 2
=
2dt 2dt 2 2dt dt 1+ t2 = ∫ 1+ t 2 = ∫ =∫ = 2∫ = 2 2 2 2 1− t 31+ t + 5⋅ 1− t 3 + 3t + 8 − 5t 8 − 2t 2 3+ 5⋅ 1+ t2 1+ t2 1 4 dt = 1 dt = − 1 du = − 1 ln 2 − t 1 1 2−t 4 ∫ 2−t 4∫ u 4 dt dt 4 4 = 2∫ = = + dt = = ∫ ( 2 − t )( 2 + t ) ∫ 2 − t 2 + t ∫ 2 − t = u 2 4 −t2 − dt = du dt = −du
(
(
)
(
)
)
x 1 1 1 2+t 1 2 +C = − ln 2 − t + ln 2 + t = ln = ln x 4 4 4 2−t 4 2 − tg 2 1 A B A( 2 + t ) + B ( 2 − t ) 2 A + At + 2 B + Bt t ( A + B ) + 2 A + 2 B = + = = = ( 2 − t )( 2 + t ) 2 − t 2 + t ( 2 − t )( 2 + t ) ( 2 − t )( 2 + t ) ( 2 − t )( 2 + t ) A+ B = 0 2 A + 2B = 1 2A + 2A = 1 4A = 1 1 1 A= B= 4 4 2 + tg
147. dx
∫ 7 cos 2 x + 3 sin 2 x
dx 1 dx 2 2 : cos x 1 + tg 2 x dx cos x cos x = = = = : cos 2 x ∫ 7 + 3tg 2 x ∫ 7 + 3tg 2 x ∫ 3 + 3tg 2 x 2
(
)
tgx = t x = arctgt dt 1+ t2 dt dt 1 dt dx 1+ t2 = = =∫ =∫ = ∫ = dt ∫ 3 2 2 3 7 7 + 3t 7 + 3t cos x 7 ⋅ 1 + t 2 7 dt t dx = 1+ 2 7 1+ t 3
(
)
7 du 1 1 7 du 7 7 3t 3 = ∫ = ⋅ ⋅∫ = arctgu = arctg +C = 2 2 7 1+ u 7 3 1+ u 7 3 7 3 7 =
89
3 ( tgx ) + C = 7 arctg 3x + C arctg 7 3 7 3 7 7 7
t
2
=
7 3 dt =
=u = 7 3
du
148. cos x = t 3 2 2 2 ∫ sin xdx = ∫ sin x ⋅ sin xdx = ∫ 1 − cos x ⋅ sin xdx = − sin xdx = dt = − ∫ 1 − t dt = sin xdx = −dt
(
= −t +
)
(
t3 x + C = − cos x + cos 3 + C 3 3
149.
∫ cos
2
)
xdx = ∫ cos x ⋅ cos xdx =
cos x = u − sin xdx = du
(
dv = cos xdx = v = sin x
[∫ cos
2
]
xdx = I =
)
= cos x ⋅ sin x + ∫ sin 2 xdx = sin x cos x + ∫ 1 − cos 2 x dx = sin x cos x + x − ∫ cos 2 xdx = I = sin x ⋅ cos x + x − I 2 I = sin x ⋅ cos x + x sin x ⋅ cos x + x I= +C 2
150.
sin ( α + β ) = sin α cos β + cos α sin β sin ( α − β ) = sin α cos β − cos α sin β sin ( α + β ) − sin ( α − β ) = 2 sin α cos β 1 ∫ sin 3x cos 3xdx = ∫ 2 ( sin 11x + sin ( − 5x ) ) dx = 11x = t dt 1 −1 cos 11x sin 11xdx = 11dx = dt = ∫ sin t = ∫ sin tdt = cos t = 11 11 11 11 dt dx = 11 = = − 5 x = t 1 1 1 dt ∫ sin ( − 5x ) dx = − 5dx = dt = ∫ sin t ⋅ − 5 = − 5 ∫ sin tdt = 5 cos t = 5 cos( − 5x ) dt dx = −5 =
1 − cos11x cos 5 x + +C 2 11 5
151.
∫ sin 3x sin ( 5x − 1) dx
cos( α + β ) = cos α cos β − sin α sin β cos( α − β ) = cos α cos β + sin α sin β
cos( α − β ) − cos( α + β ) = 2 sin α sin β sin α sin β =
90
1 ⋅ [ cos( α − β ) − cos( α + β ) ] 2
1
1
∫ sin 3x sin( 5 x − 1) dx = 2 ∫ [ cos( 3x − 5 x + 1) − cos( 3x + 5x − 1) ]dx = 2 ∫ [ cos(1 − 2 x ) − cos( 8 x − 1) ]dx = 1 − 2 x = t 1 1 1 dt ∫ cos(1 − 2 x ) dx = − 2dx = dt = ∫ cos t ⋅ − 2 = − 2 ∫ cos tdt = − 2 sin t = − 2 sin (1 − 2 x ) dt dx = − 2 = = 8 x − 1 = t dt 1 1 1 ∫ cos( 8x − 1) dx = 8dx = dt = ∫ cos t 8 = 8 ∫ cos tdt = 8 sin t = 8 sin ( 8x − 1) dt dx = 8 =
1 1 1 1 1 − sin (1 − 2 x ) − sin ( 8 x − 1) + C = − sin (1 − 2 x ) − sin ( 8 x − 1) + C 2 2 8 4 16
152. cos x = t dx sin xdx sin xdx dt ∫ sin x cos 2 x = ∫ sin 2 x cos 2 x = ∫ 1 − cos 2 x cos 2 x = − sin xdx = dt = −∫ 1 − t 2 t 2 = sin xdx = −dt
(
)
(
1 1 A B Ct + D = = + + = 2 2 2 1−t t (1 − t )(1 + t )t 1 − t 1 + t t2
(
)
(
(
)
(
)
=
A(1 + t ) ⋅ t 2 + B 1 − t 2 ⋅ t 2 + ( Ct + D ) 1 − t 2 ( A + At ) t 2 + ( B − Bt )t 2 + Ct − Ct 2 + D − Dt (1 + t ) = = (1 − t )(1 + t ) t 2 (1 − t )(1 + t )t 2
=
At 2 + At 3 + Bt 2 − Bt 3 + Ct + Ct 2 − Ct 2 − Ct 3 + D + Dt − Dt − Dt 2 = (1 − t )(1 + t )t 2
=
t 3 ( A − B − C ) + t 2 ( A + B − D ) + Ct + D (1 − t )(1 + t ) t 2
= A − B −C = 0 A+B−D =0 C =0 D =1 1 1 1 = 2 + 2 + 2 1−t 1+ t t
= −∫
91
)
)
dt 1−t2 t2
(
)
2A − C − D = 0
A=
1 2
B=
1 2
2 A −1 = 0
1 1 1 1 1 t −2+1 2 2 +C = = −∫ + + 2 dt = − − ln 1 − t + ln 1 + t + 2 2 − 2 + 1 1 − t 1 + t t
=
=
1 1 1 1 1 − cos x 1 1 − cos x 1 ln 1 − cos x − ln 1 + cos x + + C = ln + + C = ln + +C 2 2 cos x 2 1 + cos x cos x 1 + cox cos x
x y ln x + ln y = ln x ⋅ y ln x − ln y = ln
1
∫ cos nxdx = n sin nx + C
1
1 ln x = ln x 2 = ln x 2 ln x n = n ⋅ ln x
153.
2
(
)
1 + cos 2 x 1 1 + cos 2 x 2 ∫ cos xdx = cos x = 2 = ∫ 2 dx = 4 ∫ 1 + 2 cos 2 x + ( cos 2 x ) dx = 4
2
2 x = t 1 + cos 4 x 1 1 + cos 4 x dt 1 cos 2 2 x = = ∫ 1 + 2 cos 2 x + dx = ∫ cos 2 xdx = 2dx = dt = ∫ cos t = sin t = 2 4 2 2 2 dt dx = 2 =
1 1 1 1 1 3 1 1 ⋅ x + 2 ⋅ sin 2 x + x + ⋅ sin 4 x + C = x + sin 2 x + sin 4 x + C 4 2 2 2 4 8 4 32
154.
∫x
dx x2 −1
=
1 =t x 1 x= t dx = −
1
dt t −2 1 1− t2 x2 −1 = 2 −1 = t t2
(
= − arcsin
)
− dt − dt 2 dt t t2 =∫ =∫ = −∫ = − arcsin t + C 1 1− t2 1 1− t2 1− t2 ⋅ ⋅ t t t t2
1 +C x
155. 1 2t + 1 x = 2+ = t t 2 1 4t + 4t + 1 − dt t= x2 = 2 x−2 t dx t2 =∫ = ∫ x − 2 x 2 − 6x + 1 = 2 2 − dt 4t + 4t + 1 12t + 6 2 1 1 − 2 t − 7 t dx = 2 x − 6x + 1 = − +1 = ⋅ t t t2 t t2 2 2 2 2 4t + 4t + 1 − 12t + 6t + t 1 − 2t − 7t = = 2 t t2 x−2=
92
1 t
dt dt dt dt t2 = −∫ = −∫ = −∫ = −∫ = 2 2 1 1 − 2t − 7t 2 1 − 2t − 7t 2 1 − 2t + 7t 2 1 − 7 t + t ⋅ 7 t t dt dt dt dt = −∫ = −∫ = −∫ = −∫ 2 2 1 2 1 1 2 1 8 1 1 t + 1 − 7 t + + − 7 t + 1 − 7 ⋅ t + − 7 7 8 7 49 7 7 7 1− 8 7 49
(
1
=−
⋅∫
8 7
7
=−
8 ⋅ 7 ∫
⋅
8
1 t + dt = 7 =u 2 8 1 7 t + 7 1− 8 7
arcsin 7
1
=−
dt
)
= du
8 7
=
8 dt = du = 7
1 1 t + 1 + du 1 7 + C = − 1 arcsin x − 2 7 + C = =− arcsin 7 8 7 8 1− u2 7 7 7+ x−2 1 x+5 +C = − arcsin +C 8 ⋅ ( x − 2 ) 7 8 ⋅ ( x − 2)
156.
∫ x⋅(
dx x + 5 x2
x = t 10
10t 9 dt
) = dx = 10t dt = ∫ t ( t 9
10
10
+ 5 t 20
)
10t 9 dt 10t 9 dt dt = ∫ 10 5 4 = ∫ 9 = 10 ∫ 5 = 4 t t +t t ⋅ t ⋅ t ( t + 1) t ( t + 1)
(
)
1 At 4 + Bt 3 + Ct 2 + Dt + E F = + = 5 5 ( t + 1) t ( t + 1) t =
( At
4
)
+ Bt 3 + Ct 2 + Dt + E ⋅ ( t + 1) + t 5 F At 5 + At 4 + Bt 4 + Bt 3 + Ct 3 + Ct 2 + Dt 2 + Dt + Et + Ft 5 = = t 5 ( t + 1) t 5 ( t + 1)
t 5 ( A + F ) + t 4 ( A + B) + t 3 ( B + C ) + t 2 ( C + D) + t( D + E ) + E = = t 5 ( t + 1) E =1 D+E =0 C+D=0 B+C =0 A+ B = 0 A+ F = 0 D = −1 C =1 B = −1 A =1 F = −1 =
t4 − t3 + t2 − t +1 1 1 dt = 10 ∫ t −1 − t − 2 + t −3 − t − 4 + t −5 − = 10∫ − dt = 5 t + 1 t + 1 t
93
t −2+1 t −3+1 t −4+1 t −5+1 = 10 ln t − 10 + 10 + 10 − 10 − ln t + 1 + C = − 2 +1 − 3 +1 − 4 +1 − 5 +1 10 x 1 1 1 1 = 10ln 10 + 10 − 5 + − +C x +1 x 2 x 310 x 3 45 x 2
157. x = 3 sin t dx = 3 cos tdt dx 3 cos tdt cos tdt cos tdt x =∫ = 3∫ = 3∫ = ∫ 3 − x 2 = sin t = 3 3 − 3 sin 2 t 3 1 − sin 2 t 3 1 − sin 2 t x t = arcsin 3 cos tdt x =∫ = ∫ dt = t = arcsin +C 3 cos 2 t
(
)
158. 1 ( 2 sin x cos x ) 2 cos 2 xdx = 4 1 1 1 sin 2 x sin 2 2 x ⋅ cos 2 x 1 + cos 2 x 1 1 2 dx = = ∫ ( sin 2 x ) 2 ⋅ + dx = ∫ sin 2 x ⋅ + cos 2 x dx = ∫ 4 2 4 4 2 2 2 2 1 1 1 − cos 4 x 1 = ∫ sin 2 2 x + sin 2 x cos 2 x dx = ∫ dx + ∫ sin 2 2 x cos 2 xdx = 8 8 2 8 3 1 1 1 1 1 sin 2 x 2 = ∫ (1 − cos 4 x ) dx + ∫ sin 2 x cos 2 xdx = x − sin 4 x + ⋅ +C 16 8 16 4 6 8
∫ sin
2
x cos 4 xdx = ∫ ( sin x cos x ) 2 cos 2 xdx = ∫
(
)
4 x = t 1 1 ∫ cos 4 xdx = 4dx = dt = 4 ∫ cos tdt = 4 sin 4 x dt dx = 4 sin 2 x = t 1 2 1 1 t 3 t 3 sin 3 2 2 sin 2 x cos 2 xdx = = t dt = ⋅ = = 2 cos 2 xdx = dt 2 ∫ 2∫ 2 3 6 6 =
x sin 4 x sin 3 2 x − + +C 16 64 48
Određeni integrali 94
Integralna suma za funkciju y = f ( x ) na intervalu [ a, b] i podjeli n
a = x0 < x1 < ⋅ ⋅ ⋅ < x n = b tog intervala je
∑f (ξ )∆xi
.
i =1
xi −1 ≤ ξ i ≤ xi , ∆xi = xi − xi −1 , i = 1,2,3,..., n b
n
lim ∑ f ( ξ i )∆xi = ∫ f ( x ) dx = Px
max ∆xi →0 i =1
a
Γf f ( ξ2 ) b
∫ f ( x ) dx
a
a
b
Osobine određenih integrala a
∫ f ( x ) dx = 0 a
ako je funkcija neparna. ako je funkcija parna funkcija. Newton-Leibnitz-ova formula
Funkcija f ( x ) neprekidna na [ a, b] i ϕ ( x ) njena primitivna funkcija tj. ϕ ( x ) = f ( x ) b
tada je
∫ f ( x ) dx = ϕ ( x ) a
159. 95
b a
= ϕ( b) − ϕ( a) .
4
x2 xdx = ∫ 2 0
4
42 02 − =8 2 2
= 0
160. 1
x n +1 ∫ x dx = n + 1 0
1n +1 0 n +1 1 = − = n +1 n +1 n +1
1
n
0
161. 0
3x 4 + 3x 2 + 1 dx = x2 +1
∫π
−
3x 4 + 3x 2 + 1 1 x3 2 3 ∫ x 2 + 1 dx = ∫ 3x + x 2 + 1 dx = 3 3 + arctgx = x + arctgx =
4
(
= x 3 + arctgx
)
0 −
π 4
3
π π π π = 0 + 0 − − + arctg − = + arctg 4 4 4 64 3
162.
A B A( x − 1) + B( x + 2 ) Ax − A + Bx + 2 B + = = = ( x + 2)( x − 1) ( x + 2)( x − 1) x + x − 2 x + 2 x −1 x( A + B ) − A + 2 B = A+ B = 0 ( x + 2)( x − 1) +∞ dx − A + 2B = 1 = ∫ x2 + x − 2 = 2 3B = 1 1 1 B= A=− 3 3 1
2
=
1 1 3 + 3 dx = − 1 ln x + 2 + 1 ln x − 1 = ln 3 x − 1 3 x + 2 x + 2 x −1 3
+∞
∫ 2
=
−
+∞
=
2
2
− 1 2 = − ln 3 = − ln 2 3 = ln 2 4 3
163. y = 4x ⇒ y = 2 x 4 4 y = x+ 5 5 Presjek funkcija f1 i f2 y 2 = 4x 4 4 y = x+ 5 5 2
4 4 x + = 4x 5 5
96
( f1 ) ∩ ( f 2 ) je rješenje sistema jednačina.
2
(
)
4 2 x + 1 = 4x 5 16 2 25 x + 2x + 1 = 4x ⋅ 25 4 2 4 x + 8 x + 4 = 25 x
(
)
4 x 2 − 17 x + 4 = 0 17 ± 289 − 64 8 17 ± 225 17 ± 15 x1, 2 = = 8 8 2 1 x1 = = 8 4 32 x2 = =4 8 x1, 2 =
3 4 2 2 4x 4 x 4 x 4 4 3 2 2 4 P = ∫2 x − − dx = 2 ⋅ − ⋅ − x = x − x − x 3 5 2 5 1 3 5 5 5 5 1 4 4 2 4 2 4 4 1 2 1 4 1 32 32 16 1 1 1 = ⋅ 8 − ⋅ 16 − ⋅ 4 − ⋅ − ⋅ − ⋅ = − − − + + = 5 5 5 5 6 40 5 3 8 5 16 5 4 3 3 4
=
1280 − 768 − 384 − 20 + 3 + 24 135 27 9 = = = 120 120 24 8
164. y 2 = 2x + 1 x − y −1 = 0
( 4,3)
x = y +1 y 2 = 2( y + 1) + 1 y2 = 2y + 2 +1 y2 − 2y − 3 = 0 y1 = −1 y2 = 3 x = y +1 x1 = −1 + 1 = 0 x2 = 3 + 1 = 4
97
1 − ,0 2
P∆
4 1 4
=
0
P=2∫
1 − 2
= 2
1
4
1 2 x + 1dx + + ∫ 2 x + 1dx + ∫ 2 0 1
( 2 x + 1) 3
3
0 1 − 2
+
1 + 2
(
)
2 x + 1 − ( x − 1) dx =
( 2 x + 1) 3
3
+ 0
1
( 2 x + 1) 3
3
x2 − 1 2 4
4
+x
1
4
=
1
1 2 1 1 1 16 1 1 3 3 1 27 3 3 = 2 ⋅ − 0 + + − + − − 8 − + 4 − 1 = + − + 1 + + 3 = 3 3 3 2 3 2 3 2 3 3 2 3
165. x2 2 1 y= 1+ x2 x2 = 2y 1 y= 1+ 2y y=
2y2 + y −1 = 0
y
y=
x2 2
(1,0)
y=
1 1+ x2
0
−1± 1+ 8 −1± 3 = 4 4 y1 = −1 y1, 2 =
x
1 2 = −2 ∈ R
y2 = x1, 2
x3, 4 = ±1 1 1 x2 P = ∫ − 2 2 −1 1 + x π 1 3π − 2 = − = 2 3 6
1 x3 dx = arctgx − ⋅ 2 3
1 −1
= arctg1 −
1 1 1 − arctg ( − 1) + = 2arctg1 − = 6 6 3
166. Odrediti zapreminu V koja nastaje rotacijom prave y = y
y=
1 1+ x2 y=0
x= − 1 98
x=1
1 oko x – ose. 1+ x2
1+ x2 − x2
1+ x2 x 2 dx dx − ∫ 1+ x2 2 ∫ 1+ x2 2 = 1+ x2 dx x xdx =∫ − ∫x⋅ dx = arctgx − ∫ x ⋅ 2 2 1+ x 1+ x 1+ x2
(
1
2
1
1 V = π ∫ y 2 dx = π ∫ dx = 2 1 + x −1 −1
)
dx = ∫
(
(
)
(
)
)
(
)
2
=
x 1 1 x = arctgx + − arctgx = arctgx + 2 2 2 2 1+ x 2 1+ x2 xdx ∫ x ⋅ 1 + x 2 2 =I1
(
(
)
(
=
)
)
xdx ′ x=u = v 1+ x2 2 1+ x = t xdx I1 = x ⋅ xdx = dx = du v=∫ = 2 xdx = dt = ∫ 2 2 2 2 1 + x 1 + x = dt = xdx = 2 1 dt 1 t − 2+1 1 1 v= ∫ 2 = ⋅ =− =− 2 2 t 2 − 2 +1 2t 2 1+ x −x 1 x 1 +∫ dx = − + arctgx = 2 2 2 2 2 1+ x 21+ x 2 1+ x 1 1 1 x 1 1 1 1 = π ⋅ arctgx + = π ⋅ arctg1 + − arctg ( − 1) − = π arctg1 + = 2 2⋅2 2 2 ⋅ 2 2 2 1 + x −1 2 2
(
(
)
)
(
)
(
(
)
(
(
)
(
)
)
2 π π 2 + 2π π 1 π = π ⋅ + = + = 2 4 4 2 4
Diferencijalne jednačine 99
)
Diferencijalne jednačine prvog reda y = y ( x ) , y ′ = f ( x, y ) . Oblik jednačine je y ′ = f ( x, y ) Tipovi diferencijalnih jednačina 1.) Jednačina koja razdvaja promjenljive f ( x ) dx = F( y ) dy rješenje : ∫ f ( x ) dx = ∫ F( y ) dy + C . 2.) Homogena diferencijalna jednačina y ′ = ϕ y x
y x
pomoću smjene = z
y = x⋅z
y ′ = z + x ⋅ z ′ rješenje jednačine.
3.)Linearna diferencijalna jednačina y′ + f ( x) y = g ( x) f ( x ) , g ( x ) - neprekidne funkcije − f ( x ) dx f dx ⋅ ∫ ∫ ( x ) ⋅ g ( x ) dx + C rješenje : y = ∫
dx
ako je linearna diferencijalna jednačina data u obliku dy + f ( y ) ⋅ x = g ( y ) − f ( y ) dy f dy ⋅ ∫ ∫ ( y ) ⋅ g ( y ) dy + C . tada je rješenje : x = ∫
3.) Bernulijeva diferencijalna jednačina y′ + f( x) y = g ( x) ⋅ y n y′ z′ = yn 1− n ydx − xdy = 0 ydx = xdy dx dy = x y ∫ dx dy ∫ x =∫ y ln x = ln y + C ln
(
100
)
xy + x ⋅ y ′ = y x
(
)
y +1 ⋅
)
y′ =
dy =y dx
y + 1 dy dx = y x
1 y
n −1
= z z ′ = (1 − n )
z′ + f ( x ) z ′ = g ( x ) linearna diferencijalna jednačina 1− n
x =C y
167.
(
( n ≠ 0 ∧ n ≠ 1) uvodi se smjena
∫
dy dx
y′ yn
∫
(
)
y + 1 dy dx =∫ y x
1 1 − 1 ∫ y + y dy = ∫ x 2 dx 1 −1+1 y2 x − 2 +1 + ln y = +C − 1 +1 − 1 +1 2 2 1
y2 + ln y = 2 x + C 1 2 2 y + ln y = 2 x + C
168.
169.
y ⋅ y′ + x = 1 dy y⋅ + x =1 dx dy y⋅ = 1− x dx
y ⋅ dy = (1 − x ) dx
(
dy = x dx x dx ydy = 2 1 + x ∫
(
)
x
dx
∫
∫ ydy = ∫ 2(1 + x )
∫ ydy = ∫ (1 − x ) dx 2
)
2 ⋅ 1 + x y ⋅
y2 1 = ⋅ ln 1 + x + C ⋅ 2 2 2
2
y x = x− +C ⋅2 2 2 y 2 = 2x − x 2 + C
y 2 = ln 1 + x + C
170.
y − xy ′ − yy ′ = x y − x = y ′( x + y ) y−x = y′ y+x y−x :x y′ = y+x :x y −1 y′ = x y +1 x z −1 z + xz ′ = z +1 dz z − 1 z+x = ⋅ ( z + 1) dx z + 1 ( z + 1)( z + xz ′) = z − 1
101
y =x x
y = xz
y ′ = z + xz ′
z 2 + xz ′ ⋅ z + z + x ⋅ z ′ − z = −1 z ′x( z + 1) + z 2 = −1 −1− z2 1+ z dz − 1 − z 2 x⋅ = dx z +1 ( z + 1) dz = dx x −1− z2 ( z + 1) dz = dx − x ∫ 1+ z2 ( z + 1) dz = dx −∫ ∫x 1+ z2 1 − ln 1 + z 2 + arctgz = ln x + C 2 xz ′ =
1 y2 y − ln 1 + 2 + arctg = ln x + C 2 x x 1 y2 y − ln 1 + 2 − arctg = ln x + C 2 x x y 1 x2 + y2 − arctg = ln x ⋅ C + ln x 2 x2 − arctg
y x2 + y2 = ln C ⋅ x + ln x x2
− arctg
y = ln C ⋅ x 2 + y 2 x
171.
x y′ = y x +1 x( x + 1) = y ⋅ y ′ dy x( x + 1) = y dx x ⋅ ( x + 1) dx = ydy
∫ (x
2
)
+ x dx = ∫ ydy
x3 x2 y 2 + = + C ⋅6 3 2 2 2 x 3 + 3x 2 = 3 y 2 + C
102
1 + z 2 = t 1 dt 1 z ∫ 1 + z 2 dz = 2 zdz = dt = 2 ∫ t = 2 ln z dt zdz = 2 1 = ln 1 + z 2 2
172.
7 x + xy + y ′( y + xy ) = 0 7 − −1 dy y = 1 dx +1 x dy dx = 7 1 − −1 +1 y x dy dx = − 7 − y 1+ x y x ydy xdx = − 7 − y 1+ x ∫ ydy xdx ∫ − 7 − y = ∫1+ x y+7−7 x +1−1 −∫ dy = ∫ dx 7+ y 1+ x y+7 7 dx − ∫ dy + ∫ dy = ∫ dx − ∫ 7+ y 1+ x 7+ y − y + 7 ln 7 + y = x − ln 1 + x + C
174. x 2 + y 2 = 2 xyy ′ y′ =
x2 + y2 / : x2 2 xy / : x 2
y2 1+ 2 x ′ y = y 2 x 1+ z2 z + xz ′ = 2z 2 1+ z xz ′ = −z 2z 1 + z 2 − 2z 2 xz ′ = 2z dz 1 − z 2 x = dx 2z
103
y =z x
y′ = z + x ⋅ z′
173.
xy ′ − y = xy ′ =
x2 +y2
x2 +y2 +y
y′ = 1 +
y2 x
2
+
y x
y = z y ′ = z + xz ′ x
z + xz ′ = 1 + z 2 + z xz ′ = 1 + z 2 xdz = 1 +z 2 dx dz dx = x 1 +z 2
∫
dz 1 +z
2
=∫
∫ dx x
ln z + 1 + z 2 = ln x +ln C ln
y y2 + 1 + 2 = ln C ⋅ x x x
y y2 + 1 + 2 =C ⋅ x x x y+
y 2 +x 2 =C ⋅ x x
y+
x 2 + y 2 =C ⋅ x 2
175.
− 2 zdz dx −∫ =∫ 2 x 1− z
y + y ′ = x − dx dx y = ∫ ⋅ ∫ ∫ ⋅ x dx +C
y2 ln x + ln C + ln 1 − 2 = 0 x ln x ⋅ C ln 1=
2
x −y x2
2
x
y = −x ⋅
=0
x ⋅ C x2 − y2
= 0
2
y
C ⋅ x2 − y2 x 2
x = C ⋅ x − y2
y y y
176.
ln 1 − y
−1
3 C1 = x 1− y 3
− x3
y = 1 − C1 ⋅
y = 1 + C ⋅ − x
104
3
⋅ x dx +C
[
]
g ( x ) = x
f( x) = 1
− dx dx y = ∫ C + ∫ ∫ ⋅ x dx
(
3
y = − x C + ∫ 2 x dx
)
1 y = − x C + 2 x 2
pošto je y= 1 , za x=0 imamo 1=C +
C1 ⋅ − x = 1 − y
x
]
2 x =t 2x ∫ dx = 2dx = dt = = −x ⋅ ∫ 2 x dx +C dt dx = 2 1 1 2x t ∫ dt = 2 2 1 = −x ⋅ 2 x +C 2 1 C = x + x 2 x C = + x 2
y ′ + y = x
x3 +C 3
= ln x
[∫
177.
y ′ + 3 x 2 y = 3x 2 dy = 3 x 2 (1 − y ) dx dy = 3 x 2 dx ∫ 1− y − ln 1 − y = 3
g ( x ) = x
f ( x ) =1
− ln 1 − z 2 = ln x + C
1 2
tj.
C=
1 2
traženo partikularno rješenje je x − − x y= 2
178. y′ + 2 y = x 2 + 2x g( x) = x 2 + 2x
f( x) = 2
− f dx f dx y = ∫ ( x ) ∫ ( x ) ⋅ g ( x ) dx + C
(
)
− 2 dx − 2 dx y = ∫ ⋅ ∫ ∫ ⋅ x 2 + x dx + C
[
(
)
y = −2 x ⋅ ∫ 2 x ⋅ x 2 + x dx + C
]
x 2 2 x x2 x 32 x y = −2 x ⋅ + − + C 2 4 2
(
)
y = 2 x x 2 + 2 x dx = x 2 2 x dx + 2 x2 x dx = ∫ ∫ ∫ 2 2 x x = u dx = v ′ 2 2x 1 2x = ∫ x dx = 2 xdx = u ′ v = 2 2x ′ x = u dx = v 2 2x = x − 2 x xdx = = 1 2x ∫ 2 dx = du v = 2 2 2x 2 2x x 2 2 x x2 x 2 x 1 2x 2x = = x − x + 1 2 x = − − + x − 2 2 4 2 2 4 2 x = u 2 x dx = v ′ = ∫ 2 x2 x dx = 2 ∫ x2 x dx = dx = du v = 1 2 x 2 2 x = 2 ⋅ x − 1 2 x dx = x ⋅ 2 x − 1 2 x ∫ 2 2 2
179. y ′ cos x = y sin x + cos 2 x y ′ cos x − y sin x = cos 2 x / : cos x sin x y′ − y = cos x cos x y ′ − tgx ⋅ y = cos x f ( x ) = −tgx
g ( x ) = cos x
− f dx f dx y = ∫ ( x ) ⋅ ∫ ∫ ( x ) ⋅ g ( x ) dx + C tgxdx − tgxdx y = ∫ ⋅ ∫ ∫ ⋅ cos xdx + C
cos x = t sin x dt ∫ tgxdx = ∫ cos x dx = − sin xdx = dt = −∫ t = − ln t = − ln cos sin xdx = − dt
105
− ln cos x
y=
[
⋅ ∫
⋅ cos xdx + C
[
−1
ln cos x
y=
ln cos x
⋅ ∫ cos x ⋅ cos xdx + C
[
]
]
]
1 ⋅ ∫ cos 2 xdx + C cos x 1 1 + cos 2 x y= ⋅ ∫ dx + C cos x 2 y=
1 1 1 ⋅ x + sin 2 x + C cos x 2 4 x sin 2 x y= + +C 2 cos x 4 cos x y=
180. xdy − 2 ydx = x 3 ln xdx / : dx dy x − 2 y = x 3 ln x dx x ⋅ y ′ − 2 y = x 3 ln x / : x 2 y ′ = y = x 2 ln x x 2 f( x) = − , g ( x ) = x 2 ln x x − f dx f dx u = ln x y = ∫ ( x ) ⋅ ∫ ∫ ( x ) ⋅ g ( x ) dx + C ln xdx = 1 ∫ u ′ = dx 2 2 − ∫ dx x ∫ dx y = x ⋅ ∫ x ⋅ x 2 ln xdx + C
(
)
[
y = 2 ln x ⋅ ∫ −2 ln x ⋅ x 2 ln xdx + C 2
[
−2
y = ln x ⋅ ∫ ln x ⋅ x 2 ln xdx + C
[ ⋅ [ ∫ ln xdx + C ]
y = x 2 ⋅ ∫ x − 2 ⋅ x 2 ln xdx + C y = x2
]
]
dx = v ′ v=x
= x ln x − ∫ dx = x ln x − x
]
y = x 2 ⋅ [ x ln x − x + C ]
181.
Konstanta za drugi izvod r 2
y ′′ − a y = 2
bx
r 2 − a2 = 0 polinom od r r1 = − a r2 = a
( p( r ) )
y 0 = C1 ⋅ − ax + C 2 ⋅ ax
η=
bx bx = 2 p( b ) b − a 2 − ax
y = y 0 + η = C1 ⋅ 106
bx + C2 ⋅ + 2 b − a2 ax
182.
183.
y ′′ − 2 y ′ + y = 2 x
y ′′ − 3 y ′ + 2 y = 2 x x 2 + x
2
p : r − 2r + 1 = 0 r1, 2 = 1 1x
(
)
2
r − 3r + 2 = 0 1x
y 0 = C1 ⋅ + x ⋅ C 2 ⋅ b=2 p( b ) = p( 2) p( 2) = 2 2 − 2 ⋅ 2 + 1 = 1 2 x 2 x η= = = 2 x p( 2) 1
3± 9− 4⋅2 r1 = 1 r2 = 2 b = 2 2 Kada je b jednako sa jednim r1 ili r2 tada je η = x ⋅ ( a 0 + a1 x ) ⋅ 2 x r1, 2 =
y 0 = C1 ⋅ r1x + C 2 ⋅ r2 x y 0 = C1 ⋅ x + C 2 ⋅ 2 x
y = y 0 + η = C1 ⋅ x + x ⋅ C 2 ⋅ x + 2 x
184.
y +1 y′ = x dy y + 1 = dx x dy dx = y +1 x
ln y + 1 = ln x + ln C y +1 = C ⋅ x y = Cx − 1
y 1 = x x 1 1 y′ − ⋅ y = x x 1 1 f( x) = − g( x) = x x dx 1 − ∫ dx 1 ∫ y = x ⋅ ∫ x ⋅ dx + C x −1 1 y = ln x ⋅ ∫ ln x ⋅ dx + C x 1 1 y = x ⋅ ∫ ⋅ ⋅ dx + C x x y′ −
[
y = x ⋅ ∫ x − 2 dx + C 1 y = x ⋅ − + C x y = Cx − 1
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Sadržaj stranica Funkcija – definicija ................................................................................ 3 Granične vrijednosti – ( limesi) .............................................................. 10 Granične vrijednosti funkcije ................................................................. 29 Diferencijalni račun ................................................................................. 35 Izvod .......................................................................................................... 36 Izvod složenih funkcija ............................................................................ 37 Funkcije .................................................................................................... 40 Integrali .................................................................................................... 75 Parcijalna integracija .............................................................................. 85 Određeni integrali ................................................................................... 95 Newton – Leibnitz-ova formula ............................................................. 95 Diferencijalne jednačine ......................................................................... 100 Sadržaj ..................................................................................................... 108
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