Upload
safet-dzajic
View
262
Download
1
Embed Size (px)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 1/24
UNIVERZITET U SARAJEVUGRAĐEVINSKI FAKULTETODSJEK ZA GEODEZIJU
PREDMET: INŽINJERSKA MATEMATIKA 3
ZADAĆA 12
Sarajevo 1!"1" Zora# Pe$rov%&
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 2/24
Zadatak 1:Me$o'o( )o#a*#%+ ra,-%)a r%je.%$% r/0#% ro0-e(
Δu=−3,
u x , y =0,
x , y ∈∂ Ω ,
Ω={ x , y ∣ x2 y
21} ,
h=1
3
Rješenje: za čvor i , j : u i−1, jui 1, ju i , j−1ui , j 1−4⋅ui , j =h2⋅ f
h2⋅ f =
1
32
⋅−3=−1
3
Oblast je simetrična , pa je dovoljno računati samo za prvi kvadrant.
0,0:
u1,0u0,1u0,−1u−1,0−4⋅u0,0=−1
3
−4⋅u0,02⋅u0,12⋅u1,0=−1
3
=−4⋅u0,04⋅u0,1
0,1
u0,2u0,0u1,1u−1,1−4⋅u0,1=−1
3
u0,0−4⋅u0,1u0,22⋅u1,1=−1
3
0,2
u0,3u0,1u1,2u−1,2−4⋅u0,2=−1
3
0u0,1−4⋅u0,22⋅u1,2=−1
3
1,1
u1,0u1,2u0,1u2,1−4⋅u1,1=−1
3
2⋅u0,1−4⋅u1,12⋅u1,2=−1
3
1,2
u1,1u1,3u0,2u2,2−4⋅u1,2=−13
u0,2u1,1−4⋅u1,2=−1
3
u0,0=3
4 u0,1=
2
3 u0,2=
5
12 u1,1=
7
12 u1,2=
1
3
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 3/24
Zadatak 2:Da$% / %#$e4ra-%:
A= ∫1
2
e− x
2
dx
B= ∫
6
4
x⋅tan x dx
a!5 Kor%$e&% o.$e $rae,#o % o.$e S%(o#ovo rav%-o %,ra*/#a$% %#$e4ra-e A % 6 a $a*#o.&/78"!""""9!0!5 I,ra*/#a$% %#$e4ra-e A % 6 o(o&/ Ga/ov%+ )va'ra$/r#%+ or(/-a; re'a % 3!
Rješenje:a!5 %! O.$e $rae,#o rav%-o:
Integral A:
a=1, b=2
f x=e− x
2
f ! ! x =4⋅ x2⋅e
− x2
−2⋅e− x
2
" 2=∣ f ! !
ab
2 ∣=0.73779457193305
n= b−a3⋅ " 2
12⋅# =35.066
n≈36
h=b−a
n =
1
36
A1=h
2⋅ f x0 f x362⋅∑
i =1
35
f x i
x i= x0i⋅h , i=0...n
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 4/24
A1≈0,135300
n=72
h=b−a
n =
1
72
A2=h
2⋅ f x0 f x722⋅∑i=1
71
f x i
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 3
i
0 1, 000000 0, 367879
1 1, 027778 0, 347731
2 1, 055556 0, 328179
3 1, 083333 0, 309248
4 1, 111111 0, 290960
5 1, 138889 0, 273332
6 1, 166667 0, 256376
7 1, 194444 0, 240101
8 1, 222222 0, 224512
9 1, 250000 0, 209611
10 1,277778 0,195398
11 1,305556 0,181868
12 1,333333 0,169013
13 1,361111 0,156825
14 1,388889 0,145292
15 1,416667 0,134399
16 1,444444 0,124131
17 1,472222 0,114470
18 1,500000 0,105399
19 1,527778 0,096897
20 1,555556 0,088944
21 1,583333 0,081517
22 1,611111 0,074595
23 1,638889 0,068156
24 1,666667 0,062177
25 1,694444 0,056634
26 1,722222 0,051506
27 1,750000 0,046771
28 1,777778 0,042405
29 1,805556 0,038387
30 1,833333 0,034697
31 1,861111 0,031313
32 1,888889 0,02821533 1,916667 0,025385
34 1,944444 0,022803
35 1,972222 0,020452
36 2,000000 0,018316
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 5/24
A2≈0,135268
∣ A1− A2∣# A≈0,1353
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a <
i
0 1,000000 0, 367879
1 1,013889 0, 357732
2 1,027778 0, 347731
3 1,041667 0, 337878
4 1,055556 0, 328179
5 1,069444 0, 318634
6 1,083333 0, 309248
7 1,097222 0, 300023
8 1,111111 0, 290960
9 1,125000 0, 282063
10 1, 138889 0, 273332
11 1, 152778 0, 264769
12 1, 166667 0, 256376
13 1, 180556 0, 248153
14 1, 194444 0, 240101
15 1, 208333 0, 232220
16 1, 222222 0, 224512
17 1, 236111 0, 216976
18 1, 250000 0, 209611
19 1, 263889 0, 202419
20 1, 277778 0, 195398
21 1, 291667 0, 188548
22 1, 305556 0, 181868
23 1, 319444 0, 175357
24 1, 333333 0, 169013
25 1, 347222 0, 162837
26 1, 361111 0, 156825
27 1, 375000 0, 150977
28 1, 388889 0, 145292
29 1, 402778 0, 139766
30 1, 416667 0, 134399
31 1, 430556 0, 129188
32 1, 444444 0, 124131
33 1, 458333 0, 119226
34 1, 472222 0, 114470
35 1, 486111 0, 109862
36 1, 500000 0, 105399
37 1, 513889 0, 101078
38 1, 527778 0, 096897
39 1, 541667 0, 092853
40 1, 555556 0, 088944
41 1, 569444 0, 085166
42 1, 583333 0, 081517
43 1, 597222 0, 077994
44 1, 611111 0, 074595
45 1, 625000 0, 07131746 1, 638889 0, 068156
47 1, 652778 0, 065110
48 1, 666667 0, 062177
49 1, 680556 0, 059352
50 1, 694444 0, 056634
51 1, 708333 0, 054020
52 1, 722222 0, 051506
53 1, 736111 0, 049091
54 1, 750000 0, 046771
55 1, 763889 0, 044543
56 1, 777778 0, 042405
57 1, 791667 0, 040354
58 1, 805556 0, 038387
59 1, 819444 0, 036502
60 1, 833333 0, 034697
61 1, 847222 0, 03296862 1, 861111 0, 031313
63 1, 875000 0, 029729
64 1, 888889 0, 028215
65 1, 902778 0, 026768
66 1, 916667 0, 025385
67 1, 930556 0, 024064
68 1, 944444 0, 022803
69 1, 958333 0, 021600
70 1, 972222 0, 020452
71 1, 986111 0, 019358
72 2, 000000 0, 018316
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 6/24
Integral B:
a=
6, b=
4
f x= x⋅tan x
f ! ! x=2⋅cos x x⋅sin x
cos x 3
" 2=∣ f ! ! ab
2 ∣=4.77340836264294
n=
b−a
3
⋅ " 2
12⋅# =11.94790084035262
n≈12
h=b−a
n =0.021911747619712
B=h
2⋅ f x0 f x12 2⋅∑
i =1
11
f x i
xi= x0i⋅h , i=0...n
B1≈0,135138
n=24
h=b−a
n =0,010908
B2=h
2⋅ f x0 f x242⋅∑
i=1
23
f xi
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 9
i0 0,523599 0, 302300
1 0,545415 0, 330966
2 0,567232 0, 361367
3 0,589049 0, 393590
4 0,610865 0, 427732
5 0,632682 0, 463902
6 0,654498 0, 502214
7 0,676315 0, 542800
8 0,698132 0, 585802
9 0,719948 0, 631378
10 0, 741765 0, 679702
11 0, 763582 0, 730970
12 0, 785398 0, 785398
x i f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 7/24
B2≈0,135100
∣ B1− B2∣#
B≈0,1351
a!5 %%! S%(o#ovo rav%-o: Integral A:
a=1, b=2
f x=e− x
2
f ! ! ! ! x =16⋅ x4⋅e
− x2
−48⋅ x2⋅e
− x2
12⋅e− x
2
" 4=∣ f ! ! ! ! ab
2 ∣=1.580988368427965
n=b−a⋅4
b−a⋅ "
4
180⋅# =3.640588067797857
n≈4
h=b−a
n =
1
4
A1=
h
3⋅ f x
0 f x
42⋅∑
i=1
1
f x2⋅i4⋅∑
i=1
2
f x2⋅i−1
x i= x0i⋅h , i=0...n
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a =
i
0 0,523599 0,302300
1 0,534507 0,316421
2 0,545415 0,330966
3 0,556324 0,345944
4 0,567232 0,361367
5 0,578140 0,377244
6 0,589049 0,393590
7 0,599957 0,410415
8 0,610865 0,427732
9 0,621774 0,445557
10 0,632682 0,463902
11 0,643590 0,482782
12 0,654498 0,502214
13 0,665407 0,522215
14 0,676315 0,542800
15 0,687223 0,563990
16 0,698132 0,585802
17 0,709040 0,608258
18 0,719948 0,631378
19 0,730857 0,655185
20 0,741765 0,679702
21 0,752673 0,704955
22 0,763582 0,730970
23 0,774490 0,757775
24 0,785398 0,785398
xi
f(xi)
i
0 1, 000000 0, 367879
1 1, 250000 0, 209611
2 1, 500000 0, 105399
3 1, 750000 0, 046771
4 2, 000000 0, 018316
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 8/24
A1≈0,135210
n=8
h=b−a
n =
1
8
A2=h
3⋅ f x0 f x82⋅∑
i=1
3
f x2⋅i4⋅∑i=1
4
f x2⋅i−1
A2≈0,135254
∣ A1− A2∣#
A≈0,1352
Integral B :
a=
6 , b=
4
f x = x⋅tan x
f ! ! ! ! x=8⋅ x⋅ se$ x 2⋅tan x 316⋅ se$ x 2⋅tan x
216⋅ x⋅ se$ x4⋅tan x8⋅ se$ x 4
" 4=∣ f ! ! ! ! ab
2 ∣=59.20340303524299
n=b−a ⋅4
b−a⋅ "
4
180⋅# =1.686501856759905
n≈2
h=b−a
n =0.15523219660257
B1=
h
3⋅ f x0 f x24⋅∑
i=1
1
f x2⋅i−1
x i= x0i⋅h , i=0...n
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a >
i
0 1, 000000 0, 367879
1 1, 125000 0, 282063
2 1, 250000 0, 209611
3 1, 375000 0, 150977
4 1, 500000 0, 105399
5 1, 625000 0, 071317
6 1, 750000 0, 046771
7 1, 875000 0, 029729
8 2, 000000 0, 018316
xi
f(xi)
i
0 0, 523599 0, 302300
1 0, 654498 0, 502214
2 0, 785398 0, 785398
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 9/24
B1≈0,135113
n=4
h=b−a
n =0,130900
B2=h
3⋅ f x0 f x42⋅∑
i =1
1
f x2⋅i4⋅∑i=1
2
f x2⋅i−1
B2≈0,135088
∣ B1− B2∣#
B≈0,13510!5 Ga/ove )va'ra$/r#e or(/-e:
Integral A:
a=1, b=2
f x =e− x
2
t i =b−a
2 ⋅ xi
ba
2 , i=1...n
kvadraturna formula reda 2n=2:
x1=−1
3
, t 1=1.211324865405187
x2= 1
3 , t 2=1.7886751345948137
A=b−a
2 ⋅ f t 1 f t 2≈0.1357
kvadraturna formula reda3n=3:
x1=− 3
5 , t 1=1.112701665379258
x2=0, t 2=1.5
x3=
35
, t 3=1.887298334620742
A=b−a
2 ⋅
5
9⋅ f t 1
8
9⋅ f t 2
5
9⋅ f t 3≈0.1353
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a ?
i
0 0,523599 0,302300
1 0,589049 0,393590
2 0,654498 0,502214
3 0,719948 0,631378
4 0,785398 0,785398
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 10/24
Integral B:
a=
6 , b=
4
f x= x⋅tan x
t i=b−a
2 ⋅ xi
ba
2 , i=1...n
kvadraturna formula reda2 n=2:
x1=
−1
3 , t 1=0.57892349598811
x2= 1
3 , t 2=0.73007344300763
B=b−a
2 ⋅ f t 1 f t 2≈0.1351
kvadraturna formula reda3 n=3 :
x1=− 3
5 , t 1=0.55310400259853
x2=0, t 2=0.65449846949787
x3= 3
5 , t 3=0.75589293639721
B=b−a
2 ⋅
5
9⋅ f t 1
8
9⋅ f t 2
5
9⋅ f t 3≈0.1351
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a @
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 11/24
Zadatak 3:Kor%$e&% o.$e S%(o#ovo % o.$e $rae,#o rav%-o; %,ra*/#a$% o0%( e-%e:
x2
2
y2
3 =1
a $a*#o.&/ 78"!""9!Rješenje:
x=a⋅cost , x= 2⋅cos t , ˙ x=− 2⋅sin t y=b⋅sin t , y= 3⋅sin t , ˙ y= 3⋅cost
l =∫0
2
˙ x2 ˙ y
2dt =∫
0
2
2⋅sin t 23⋅cos t
2dt
O=4⋅l
S%(o#ovo rav%-o:
a=0, b=
2
f x = 2⋅sint 23⋅cost 2
f ! ! ! ! x=
4⋅sin x2
2⋅sin x23⋅cos x 2
4⋅cos x2
2⋅sin x23⋅cos x2 −
3⋅sin x4
2⋅sin x23⋅cos x 23
2
22⋅cos x2⋅sin x 2
2⋅sin x 23⋅cos x 23
2−
3⋅cos x 4
2⋅sin x23⋅cos x 23
2
18⋅cos x 2⋅sin x
4
2⋅sin x 23⋅cos x 25
2−
18⋅cos x 4⋅sin x 2
2⋅sin x 23⋅cos x25
2−
15⋅cos x 4⋅sin x4
2⋅sin x23⋅cos x 27
2
" 4=∣ f ! ! ! ! ab
2 ∣=0.97398151933186
n=b−a⋅4
b−a ⋅ " 4
180⋅# =1.793605380472007
n≈2
h=b−a
n =0.78539816339745
l 1=h
3⋅ f x0 f x 24⋅
∑i=1
1
f x2⋅i −
1
xi = x0i⋅h , i=0...n
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1"
i
0 0, 000000 1, 732051
1 0, 785398 1, 581139
2 1, 570796 1, 414214
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 12/24
l 1≈2,479455
n=4
h=b−a
n =0,392699
l 2=h
3⋅ f x0 f x42⋅∑
i=1
1
f x2⋅i 4⋅∑i=1
2
f x2⋅i−1
l 2≈2,477385
∣l 1−l 2∣#
l ≈2,48
O=4⋅l =9,92
O.$e $rae,#o rav%-o:
a=0, b=
2 f x = 2⋅sint 23⋅cost 2
f ! ! x = sin x 2
2⋅sin x 23⋅cos x 2−
cos x 2
2⋅sin x 23⋅cos x 2−
cos x 2⋅sin x 2
2⋅sin x 23⋅cos x23
2
" 2=∣ f ! ! ab
2 ∣=0.063245553203368
n= b−a
3⋅ " 2
12⋅# =2.021246068550205
n≈3
h=b−a
n =
6
l 1=h
2⋅ f x0 f x32⋅∑
i =1
2
f x i
xi = x0i⋅h , i=0...n
l 1≈2.477379
n=6
h=b−a
n =0.523599
l 2=
h
2⋅ f x0 f x6∑
i=1
5
f x i
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 11
i
0 0,000000 1,732051
1 0,392699 1,689246
2 0,785398 1,581139
3 1,178097 1,465076
4 1,570796 1,414214
xi
f(xi)
i
0 0, 000000 1, 732051
1 0, 523599 1, 6583122 1, 047198 1, 500000
3 1, 570796 1, 414214
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 13/24
l 2≈2.477379
∣l 1−l 2∣#l ≈2,48
O=4⋅l =9,92
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1
i
0 0,000000 1,732051
1 0,261799 1,712604
2 0,523599 1,658312
3 0,785398 1,581139
4 1,047198 1,500000
5 1,308997 1,437702
6 1,570796 1,414214
xi
f(xi)
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 14/24
Zadatak 4:R%je.%$% '%ere#2%ja-#e je'#a*%#e Ko.%jeve ro0-e(e5:
A : y ! x⋅ y= x⋅ y2 , y 0=2, x∈[0,1]
B : y ! = x2 y
2 , y 1=0, x ∈[1,2]
a!5 Oj-erovo( (e$o'o(; +8"!1!0!5 Po0o-j.a#o( Oj-erovo( (e$o'o(; +8"!!2!5 RK (e$o'o(; +8"!!
Rješenje:
a! A!5n=
x− x0
h =10
xi= x0i⋅h
yi = yi−1h⋅ f x i−1 , yi−1
x1=0.1 y10.1=2.0
x2=0.2 y20.2=2.02
x3=0.3 y30.3=2.061208
x4=0.4 y40.4=2.1268291
x5=0.5 y50.5=2.222692
x6=0.6 y60.6=2.3585754 x7=0.7 y7 0.7=2.5508336
x8=0.8 y80.8=2.8277479
x9=0.9 y9 0.9=3.2412207
x10=1.0 y10 1.0=3.8950068
a! 6!5
n= x− x0
h =10
xi = x0i⋅h
y i= y i−1h⋅ f xi −1 , y i −1 x1=1.1 y11.1=0.1
x2=1.2 y21.2=0.222
x3=1.3 y31.3=0.370928
x4=1.4 y41.4=0.553687
x5=1.5 y51.5=0.780344
x6=1.6 y61.6=1.0662378
x7=1.7 y71.7=1.4359241
x8=1.8 y81.8=1.931112
x9=1.9 y91.9=2.6280313 x10=2.0 y102.0=3.6796862
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 13
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 15/24
0! A!5
n= x− x0
h =5
x i= x0i⋅h
Ai = y i−1h⋅ f xi−1 , y i−1
yi= yi−1h
2⋅ f x i−1 , yi−1 f xi−1h , Ai
x1=0.2 y
10.2=2.04
x2=0.4 y20.4=2.1780393 x3=0.6 y30.6=2.4784821
x4=0.8 y40.8=3.1461645
x5=1.0 y51.0=5.0500302
0! 6!5
n= x− x0
h =5
xi= x0i⋅h
Ai = yi−1h⋅ f xi−1 , y i−1 yi= y i−1
h
2⋅ f x i−1 , yi−1 f xi−1h , Ai
x1=1.2 y11.2=0.248
x2=1.4 y21.4=0.624214
x3=1.6 y31.6=1.2348928
x4=1.8 y41.8=2.388412
x5=2.0 y52.0=5.4278587
2! A!5
n= x− x0
h =5
x i= x0i⋅h
k 1=h⋅ f x i −1 , yi −1
k 2=h⋅ f xi−1h
2 , y i−1
k 1
2
k 3=h⋅ f x i −1
h
2 , yi −1
k 22
k 4=h⋅ f x i−1h , y i−1k 3
yi = y i−11
6⋅ k 12⋅k 22⋅k 3k 4
x1=0.2 k%=0 k&=0.04 k'=0.04121 k(=0.08501 y10.2=2.04124
x2=0.4 k%=0.08502 k&=0.1355 k'=0.1403 k(=0.2062 y20.4=2.18172
x3=0.6 k%=0.2063 k&=0.2936 k'=0.3093 k(=0.4457 y30.6=2.49135
x4=0.8 k%=0.4459 k&=0.6514 k'=0.7166 k(=1.1333 y40.8=3.21056
x5=1.0 k%=1.13554 k&=1.88954 k'=2.36006 k(=5.09225 y51.0=5.66506
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1<
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 16/24
2! 6!5
n= x− x0
h =5
xi = x0i⋅h
k 1=h⋅ f xi −1 , yi −1
k 2=h⋅ f xi−1h
2 , y i−1
k 1
2
k 3=h⋅ f xi −1h
2
, y i−1k 2
2
k 4=h⋅ f x i−1h , y i−1k 3
yi= yi−11
6⋅ k 12⋅k 22⋅k 3k 4
x1=1.2 k%=0.2 k&=0.244 k'=0.245 k(=0.3 y11.2=0.2463
x2=1.4 k%=0.3001 k&=0.3694 k'=0.3752 k(=0.4692 y21.4=0.6228
x3=1.6 k%=0.4696 k&=0.5971 k'=0.6198 k(=0.8208 y31.6=1.24342
x4=1.8 k%=0.8212 k&=1.12516 k'=1.23032 k(=1.87188 y4 1.8=2.47742
x5=2.0 k%=1.87553 k&=3.0547 k'=3.92965 k(=9.01011 y52.0 =6.61981
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 19
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 17/24
Zadatak 5:RK (e$o'o( r%je.%$% -je'e&e Ko.%jeve ro0-e(e:
a. y ! ! −5⋅ y ! 6⋅ y=0, y 0=0, y ! 0=1
x ∈[0,0.4] , h=0.2
b. y ! ! =2− y , y 0=2, y ! 0=−1
x ∈[0,0.2] , h=0.1
$. y ! =− x2⋅ y z , y 0=2
z ! = x2⋅ y3⋅ z , z 0=−2
x ∈[0,0.4] , h=0.2
Rješenje:a!5
y ! ! =5⋅ y ! −6⋅ y
z 0 x = y x
z 1 x = y ! x z
1! x = y ! ! x =5⋅ z
1 x −6⋅ z
0 x
y ! x = z 1 x
z 1 ! x =5⋅ z 1 x−6⋅ z 0 x
f 1 x , y
1, y
2= y
1! = y
2, y
10=0
f 2 x , y
1, y
2= y
2! =5⋅ y
2 x −6⋅ y
1 x , y
20=1
k 11=h⋅ f 1 x , y1, y2 ,
k 12=h⋅ f
2 x , y1,
y2 ,
k 21=h⋅ f 1 xh
2 , y1
k 112
, y2k 122
,
k 22=h⋅ f 2 xh
2 , y1
k 11
2 , y2
k 12
2 ,
k 31=h⋅ f 1 xh
2 , y1
k 212
, y2k 222
,
k 32=h⋅ f 2 xh
2 , y1
k 21
2 , y2
k 22
2 ,
k 41=h⋅ f 1 xh , y1k 31, y2k 32 ,
k 42=h⋅ f 2 xh , y1k 31, y2k 32 ,
yi ,1= y i −1,11
6
⋅k 112⋅k 212⋅k 31k 41 ,
yi ,2= yi −1,21
6⋅ k 122⋅k 222⋅k 32k 42
n= x− x1,0
h =2
xi= x0i⋅h
x1,1=0.2 k 11=0.2 k 21=0.3 k 31=0.338 k 41=0.502 y1,10.2=0.329667
x1,2=0.2 k 12=1.0 k 22=1.38 k 32=1.51 k 42=2.1044 y1,20.2=2.4807333
x2,1=0.4 k 11=0.496147 k 21=0.70466 k 31=0.779148 k 41=1.1116153 y2,10.4=1.0922296
x2,2=0.4 k 12=2.0851333 k 22=2.830012 k 32=3.0773433 k 42=4.2274992 y2,20.4=5.5019572
0!5
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1=
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 18/24
y ! ! =2− y
z 0 x = y x
z 1 x= y ! x z 1 ! x = y ! ! x =2− y
y ! x = z 1 x
z 1 ! x=2− z 0 x
f 1
x , y1,
y2
= y1
! = y2,
y1
0=2
f 2 x , y1, y2= y2 ! =2− y% , y20=−1
k 11=h⋅ f 1 x , y1, y2 ,
k 12=h⋅ f 2 x , y1, y2 ,
k 21=h⋅ f 1 xh
2 , y1
k 112
, y2k 122
,
k 22=h⋅ f 2 xh
2 , y1
k 11
2 , y2
k 12
2 ,
k 31=h⋅ f 1 x h2
, y1 k 212
, y2 k 222
,
k 32=h⋅ f 2 xh
2 , y1
k 212
, y2k 222
,
k 41=h⋅ f 1 xh , y1k 31, y2k 32 ,
k 42=h⋅ f 2 xh , y1k 31, y2k 32 ,
yi ,1= y i −1,11
6⋅k 112⋅k 212⋅k 31k 41 ,
yi ,2= yi −1,21
6⋅ k 122⋅k 222⋅k 32k 42
n= x − x1,0
h =2
x i= x0i⋅h
x1,1=0.1 k 11=−0.1 k 21=−0.1 k 31=−0.09975 k 41=−0.0995 y1,10.1=1.9001667
x1,2=0.1 k 12=0 k 22=0.005 k 32=0.005 k 42=0.009975 y1,20.1=−0.995004
x2,1=0.2 k 11=−0.0995004 k 21=−0.0990012 k 31=−0.0987525 k 41=−0.0980071
y2,10.2=1.8013308
x2,2=0.2 k 12=0.00998333 k 22=0.0149584 k 32=0.0149334 k 42=0.0198586
y2,20.2=−0.980067
2!5 y1 ! =− x2⋅ y1 y2, y10=2
y2 ! = x2⋅ y13⋅ y2, y20=−2
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1>
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 19/24
k 11=h⋅ f 1 x , y1, y2 ,
k 12=h⋅ f 2 x , y1, y2 ,
k 21=h⋅ f 1 xh
2 , y1
k 112
, y2k 122
,
k 22=h⋅ f 2 xh
2 , y1
k 112
, y2k 122
,
k 31=h⋅ f 1 xh
2 , y1
k 212
, y2k 222
,
k 32=h⋅ f 2 x h2
, y1 k 212
, y2 k 222
,
k 41=h⋅ f 1 xh , y1k 31, y2k 32 ,
k 42=h⋅ f 2 xh , y1k 31, y2k 32 ,
yi ,1= y i −1,11
6⋅k 112⋅k 212⋅k 31k 41 ,
yi ,2= yi −1,21
6⋅ k 122⋅k 222⋅k 32k 42
n= x− x
1,0
h =2
x i= x0i⋅h x
1,1=0.2 k 11=0.4 k
21=0.42 k 31=0.422 k
41=0.4444 y1,1 0.2=2.4214
x1,2=0.2 k 12=−0.4 k 22=−0.42 k 32=−0.422 k 42=−0.4444 y1,2 0.2=−2.4214
x2,1=0.4 k 11=0.44428 k 21=0.468708 k 31=0.471151 k 41=0.49851 y2,10.4=2.891818
x2,2=0.4 k
12=−0.44428 k
22=−0.468708 k
32=−0.471151 k
42=−0.49851
y2,20.4=−2.891818
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1?
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 20/24
Zadatak 6:Me$o'o( )o#a*#%+ e-e(e#a$a r%je.%$% -je'e&e r/0#e ro0-e(e:
a. y ! ! =−3⋅ x , y 0=0, y ! 1=2, Δx=h=1
3
b. y ! ! x⋅ y=0, y 0=1, y ! 1=0, Δx=h=0.25
$. y ! ! −4⋅ y3=0, y ! 0=1, y ! 0.6=1, Δx=h=0.2
Rješenje:
a!5 y ! ! )⋅ y= f
za čvor
y j−2⋅1) j−1⋅ Δx
2
6−2⋅ y j −1⋅1−
) j−1)
j
6⋅ Δx
2 y j⋅1) j ⋅ Δx
2
6=
f j−1 f
j
2⋅ Δx
2
za rubove
− y0⋅1−
)1 ⋅ Δx
2
3 y
1⋅1
)1⋅ Δx
2
6=
f 1⋅ Δx
2
2 y ! a ⋅ Δx
yn−1⋅1
)n⋅ Δx
2
6− yn⋅1−
)n ⋅ Δx
2
3=
f n⋅ Δx
2
2− y ! b⋅ Δx
a=0 b=1
[a , b]=[0,1]
[0,1
3][1
3 ,2
3] [2
3 ,1]
)=0, f =−3⋅ x
−2⋅ y1 y2=−0.16666667
y1−2⋅ y2 y3=−0.27777778
y2− y
3=−0.83333333
y1=1.277777778
y2=2.388888886
y3=3.222222216
0!5 y ! ! )⋅ y= f
za čvor
y j−
2⋅1)
j−1⋅ Δx2
6 −2⋅ y
j −1⋅1−
) j −1)
j
6 ⋅ Δx
2 y j
⋅1)
j ⋅ Δx2
6 =
f j−1 f
j
2 ⋅ Δx
2
za rubove
− y0⋅1−)
1 ⋅ Δx2
3 y1⋅1
)1⋅ Δx
2
6 =
f 1⋅ Δx
2
2 y ! a ⋅ Δx
yn−1⋅1)
n⋅ Δx2
6 − yn⋅1−
)n ⋅ Δx
2
3 =
f n⋅ Δx
2
2 − y ! b⋅ Δx
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1@
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 21/24
a=0 b=1
[a , b]=[0,1][0,0.25][0.25,0.50] [0.50,0.75][0.75,1.00]
)= x , f =0⋅ x
−1.984375⋅ y11.005208333⋅ y2=−1.002604167
1.00520833⋅ y1−1.973958333⋅ y21.0078125⋅ y3=0
1.0078125⋅ y2−1.963541667⋅ y31.010416667⋅ y4=0
1.01041667⋅ y3−0.979166667⋅ y 4=0
y1=1.21633329109
y2=1.40374603073
y3=1.53626574241
y4=1.58529550484
2!5 y ! ! )⋅ y= f
za čvor
y j−2⋅1) j−1⋅ Δx2
6 −2⋅ y j −1⋅1−
) j −1) j
6 ⋅ Δx
2 y j⋅1) j ⋅ Δx2
6 =
f j−1 f j
2 ⋅ Δx
2
za rubove
− y0⋅1−)
1 ⋅ Δx2
3 y1⋅1
)1⋅ Δx
2
6 =
f 1⋅ Δx
2
2 y ! a ⋅ Δx
yn−1⋅1)
n⋅ Δx2
6 − yn⋅1−
)n ⋅ Δx
2
3 =
f n⋅ Δx
2
2 − y ! b⋅ Δx
a=0 b=0.6
[a , b]=[0,1]
[0,0.20] [0.20,0.40][0.40,0.60])=−4, f =−3⋅ x
−1.05333333⋅ y00.97333333⋅ y1=0.14
0.97333333⋅ y0−2.10666667⋅ y10.97333333⋅ y2=−0.12
0.97333333⋅ y1−2.10666667⋅ y20.97333333⋅ y3=−0.12
0.97333333⋅ y2−1.0533333⋅ y3=−0.26
y0=0.481811074641
y1=0.665247601952
y2=0.834752235001
y3=1.01818875092
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a "
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 22/24
Zadatak 7:Me$o'o( )o#a*#%+ ra,-%)a r%je.%$% -je'e&e r/0#e ro0-e(e:
a. Δu = y , x , y ∈Ω=[0,1]×[0,1]
u x ,0= x3 , u x ,1= x
3 , x∈[0,1]
u 0, y =0, u 1, y =1, y∈[0,1]h=0.2
b. Δu=−4, x , y ∈Ω={ x , y ∣ x2 y
21}u x , y =0, x , y ∈∂ Ω
h=1
3
Rješenje:
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a 1
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 23/24
a.)
0u420.008u31−4⋅u41=h2⋅0.8
u41u430.064u32−4⋅u42=h2⋅0.8
u42u440.216u33−4⋅u43=h2⋅0.8
u4310.512u34−4⋅u44=h2⋅0.8
0u32u41u21−4⋅u31=h2⋅0.6
u31u33u42u22−4⋅u32=h2⋅0.6
u32u34u43u23−4⋅u33=h2⋅0.6
u331u44u24−4⋅u34=h2⋅0.6
0u22u31u11−4⋅u21=h2⋅0.4
u21u23u32u12−4⋅u22=h2⋅0.4
u22u24u33u13−4⋅u23=h2⋅0.4
u231u34u14−4⋅u24=h2⋅0.4
0u12u210.008−4⋅u11=h2⋅0.2
u11u13u220.064−4⋅u12=h2⋅0.2
u12u14u230.216−4⋅u13=h2⋅0.2
u131u240.512−4⋅u14=h
2
⋅0.2
u11=0.0645152, u12=0.172303, u13=0.354848, u14=0.632879,
u21=0.0857576, u22=0.213848, u23=0.406212, u24=0.672667,
u31=0.0806667, u32=0.207121, u33=0.399485, u34=0.667576,
u41=0.0537879, u42=0.158485, u43=0.34103, u44=0.622152
Zora# Pe$rov%& Za'a&a 1 S$ra#%2a
7/23/2019 Inženjerska matematika III
http://slidepdf.com/reader/full/inzenjerska-matematika-iii 24/24
0!5
za čvor i , j : u i−1, jui 1, ju i , j−1ui , j 1−4⋅ui , j =h2⋅ f
h2⋅ f =
1
32
⋅−4=−4
9
Oblast je simetrična , pa je dovoljno računati samo za prvi kvadrant.
0,0:
u1,0u0,1u0,−1u−1,0−4⋅u0,0=−4
9
−4⋅u0,02⋅u0,12⋅u1,0=−4
9 =−4⋅u0,04⋅u0,1
0,1
u0,2u0,0u1,1u−1,1−4⋅u0,1=−4
9
u0,0−4⋅u0,1u0,22⋅u1,1=−4
9
0,2
u0,3u0,1u1,2u−1,2−4⋅u0,2=−49
0u0,1−4⋅u0,22⋅u1,2=−4
9
1,1
u1,0u1,2u0,1u2,1−4⋅u1,1=−4
9
2⋅u0,1−4⋅u1,12⋅u1,2=−4
9
1,2
u1,1u1,3u0,2u2,2−4⋅u1,2=−4
9
u0,2u1,1−4⋅u1,2=−4
9
u0,0=1 u0,1=8
9 u0,2=
5
9 u1,1=
7
9 u1,2=
4
9