pembahasan matrik

3
1. a) | 5 6 1 3 | =15 +6=21 b) | 2 3 4 1 1 1 3 0 5 | 2 3 1 1 3 0 =¿ ¿ (10 ) +(9 ) +( 0) ( 12 ) ( 0 ) ( 15) ¿ 1915 =−34 2. a) ( 3 2 10 7 ) = 1 2120 ( 7 2 10 3 ) = ( 7 2 10 3 ) b) ( 4 8 3 6 ) = 1 24 24 ( 6 8 3 4 ) =tidakmemiliki invers matriks c) ( 2 4 4 7 ) = 1 14 16 ( 7 4 4 2 ) = 1 2 ( 7 4 4 2 ) = ( 7 2 2 2 1 ) 3. P = ( 2 3 4 0 4 2 1 1 5 ) C 11 =(−1) 1+ 1 | 4 2 1 5 | =1 x ( 20 (2 ) )=−20 +2=−18 C 12 =(−1) 1+ 2 | 0 2 1 5 | =−1 x (0( 2) )=0 + 2=−2 C 13 =(−1) 1+ 3 | 0 4 1 1 | =1 x (0( 4) )=0+4=4 C 21 =(−1) 2+ 1 | 3 4 1 5 | =−1 x ( 15( 4 ) )=−15 + 4=−11 C 22 =(−1) 2+ 2 | 2 4 1 5 | =1 x (10 (4 ) )=10 +4=14 C 23 =(−1) 2+ 3 | 2 3 1 1 | =−1 x (2( 3) )=2+ 3=5 C 31 =(−1) 3+ 1 | 3 4 4 2 | =1 x ( 6( 16 ) )=616 =−10 C 32 =(−1) 3+ 2 | 2 4 0 2 | =−1 x (4( 0) )=−4+ 0=−4

description

pembahasan soal matriks SMK

Transcript of pembahasan matrik

Page 1: pembahasan matrik

1. a) | 5 6−1 3|=15+6=21

b) |2 −3 41 1 13 0 −5|

2 −31 13 0

=¿

¿ (−10 )+(−9 )+(0 )− (12 )−(0 )−(15 ) ¿−19−15=−34

2. a)( 3 210 7)= 1

21−20 ( 7 −2−10 3 )=( 7 −2

−10 3 )b)(4 8

3 6)= 124−24 ( 6 −8

−3 4 )=tidak memiliki invers matriks

c) (2 44 7)= 1

14−16 ( 7 −4−4 2 )=−1

2 ( 7 −4−4 2 )=(−7

22

2 −1)

3. P = (2 3 −40 −4 21 −1 5 )

C11=(−1)1+1|−4 2−1 5|=1x (−20− (−2 ) )=−20+2=−18

C12=(−1)1+2|0 21 5|=−1 x ( 0−(2 ) )=0+2=−2

C13=(−1)1+3|0 −41 −1|=1 x (0−(−4 ) )=0+4=4

C21=(−1)2+1| 3 −4−1 5 |=−1 x (15−(4 ) )=−15+4=−11

C22=(−1)2+2|2 −41 5 |=1 x (10−(−4 ) )=10+4=14

C23=(−1)2+3|2 31 −1|=−1 x (−2−(3 ) )=2+3=5

C31=(−1)3+1| 3 −4−4 2 |=1 x (6−(16 ))=6−16=−10

C32=(−1)3+2|2 −40 2 |=−1 x (4−(0 ))=−4+0=−4

C33=(−1)3+3|2 30 −4|=1x (−8− (6 ) )=−8−6=−14

Jadi Adj(P)=(C11 C12 C13

C21 C22 C23

C31 C32 C33)=(−18 −2 4

−11 14 5−10 −4 −14)

Page 2: pembahasan matrik

4. a) Adj (A) = [+|4 52 −1| −|1 5

0 −1| +|1 40 2|

−|0 32 −1| +|2 3

0 −1| −|2 00 2|

+|0 34 5| −|2 3

1 5| +|0 34 5|]=[−14 1 2

6 −2 4−12 −7 −12]

|2 0 31 4 50 2 −1|

2 01 40 2

=(−8 )+(0 )+ (6 )−(0 )−(20 )−(0 )=−22

A−1= 1det A

adj ( A )=−122 [−18 −2 4

−11 14 5−10 −4 −14 ]=[

911

111

−211

12

−711

−522

511

211

711

]5. b) Adj (B) = [+|

3 71 6| −|2 7

4 6| +|2 34 1|

−|0 11 6| +|1 1

4 6| −|1 04 1|

+|0 13 7| −|1 1

2 7| +|1 02 3|]=[ 11 16 −10

1 2 −1−3 −5 −3 ]

|1 0 12 3 74 1 6|

1 02 34 1

=(12 )+(7 )+(0 )−(18 )−(0 )−(2 )=−1

B−1= 1det B

adj (B )=−11 [ 11 16 −10

1 2 −1−3 −5 −3 ]=[−11 −16 10

−1 −2 13 5 3 ]

6. A . X=BA−1 . X=A−1BX=A−1B

¿ 1det A

adj (A ) .B=15 ( 4 −1

−3 2 ) x ( 5 711 3)=(

45

−15

−35

25

)x ( 5 711 3)=(

95

5

75

−3)7. X . A=BX . A . A−1=B . A−1

X=B A−1

Page 3: pembahasan matrik

B .1

det Aadj (A )=( 5 7

11 3)x 15 ( 4 −1

−3 2 )=( 5 711 3)x (

45

−15

−35

25

)=( 15

95

7 −1)