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[122220032]⎡⎢⎣122220032⎤⎥⎦
Bước 1
Bước 1.1
Choose the row or column with the most 00 elements. If there are no 00 elements choose any row or column. Multiply every element in column 11 by its cofactor and add.
Bước 1.1.1
Consider the corresponding sign chart.
|+-+-+-+-+|∣∣
∣∣+−+−+−+−+∣∣
∣∣
Bước 1.1.2
The cofactor is the minor with the sign changed if the indices match a -− position on the sign chart.
Bước 1.1.3
The minor for a11a11 is the determinant with row 11 and column 11 deleted.
|2032|∣∣∣2032∣∣∣
Bước 1.1.4
Multiply element a11a11 by its cofactor.
1|2032|1∣∣∣2032∣∣∣
Bước 1.1.5
The minor for a21a21 is the determinant with row 22 and column 11 deleted.
|2232|∣∣∣2232∣∣∣
Bước 1.1.6
Multiply element a21a21 by its cofactor.
-2|2232|−2∣∣∣2232∣∣∣
Bước 1.1.7
The minor for a31a31 is the determinant with row 33 and column 11 deleted.
|2220|∣∣∣2220∣∣∣
Bước 1.1.8
Multiply element a31a31 by its cofactor.
0|2220|0∣∣∣2220∣∣∣
Bước 1.1.9
Add the terms together.
1|2032|-2|2232|+0|2220|1∣∣∣2032∣∣∣−2∣∣∣2232∣∣∣+0∣∣∣2220∣∣∣
1|2032|-2|2232|+0|2220|1∣∣∣2032∣∣∣−2∣∣∣2232∣∣∣+0∣∣∣2220∣∣∣
Bước 1.2
Nhân 00 với |2220|∣∣∣2220∣∣∣.
1|2032|-2|2232|+01∣∣∣2032∣∣∣−2∣∣∣2232∣∣∣+0
Bước 1.3
Tính |2032|∣∣∣2032∣∣∣.
Bước 1.3.1
Có thể tìm được định thức của một 2×22×2 ma trận bằng công thức |abcd|=ad-cb∣∣∣abcd∣∣∣=ad−cb.
1(2⋅2-3⋅0)-2|2232|+01(2⋅2−3⋅0)−2∣∣∣2232∣∣∣+0
Bước 1.3.2
Rút gọn định thức.
Bước 1.3.2.1
Rút gọn mỗi số hạng.
Bước 1.3.2.1.1
Nhân 22 với 22.
1(4-3⋅0)-2|2232|+01(4−3⋅0)−2∣∣∣2232∣∣∣+0
Bước 1.3.2.1.2
Nhân -3−3 với 00.
1(4+0)-2|2232|+01(4+0)−2∣∣∣2232∣∣∣+0
1(4+0)-2|2232|+01(4+0)−2∣∣∣2232∣∣∣+0
Bước 1.3.2.2
Cộng 44 và 00.
1⋅4-2|2232|+01⋅4−2∣∣∣2232∣∣∣+0
1⋅4-2|2232|+01⋅4−2∣∣∣2232∣∣∣+0
1⋅4-2|2232|+01⋅4−2∣∣∣2232∣∣∣+0
Bước 1.4
Tính |2232|∣∣∣2232∣∣∣.
Bước 1.4.1
Có thể tìm được định thức của một 2×22×2 ma trận bằng công thức |abcd|=ad-cb∣∣∣abcd∣∣∣=ad−cb.
1⋅4-2(2⋅2-3⋅2)+01⋅4−2(2⋅2−3⋅2)+0
Bước 1.4.2
Rút gọn định thức.
Bước 1.4.2.1
Rút gọn mỗi số hạng.
Bước 1.4.2.1.1
Nhân 22 với 22.
1⋅4-2(4-3⋅2)+01⋅4−2(4−3⋅2)+0
Bước 1.4.2.1.2
Nhân -3−3 với 22.
1⋅4-2(4-6)+01⋅4−2(4−6)+0
1⋅4-2(4-6)+01⋅4−2(4−6)+0
Bước 1.4.2.2
Trừ 66 khỏi 44.
1⋅4-2⋅-2+01⋅4−2⋅−2+0
1⋅4-2⋅-2+01⋅4−2⋅−2+0
1⋅4-2⋅-2+01⋅4−2⋅−2+0
Bước 1.5
Rút gọn định thức.
Bước 1.5.1
Rút gọn mỗi số hạng.
Bước 1.5.1.1
Nhân 44 với 11.
4-2⋅-2+04−2⋅−2+0
Bước 1.5.1.2
Nhân -2−2 với -2−2.
4+4+04+4+0
4+4+04+4+0
Bước 1.5.2
Cộng 44 và 44.
8+08+0
Bước 1.5.3
Cộng 88 và 00.
88
88
88
Bước 2
Since the determinant is non-zero, the inverse exists.
Bước 3
Set up a 3×63×6 matrix where the left half is the original matrix and the right half is its identity matrix.
[122100220010032001]⎡⎢⎣122100220010032001⎤⎥⎦
Bước 4
Bước 4.1
Perform the row operation R2=R2-2R1R2=R2−2R1 to make the entry at 2,12,1 a 00.
Bước 4.1.1
Perform the row operation R2=R2-2R1R2=R2−2R1 to make the entry at 2,12,1 a 00.
[1221002-2⋅12-2⋅20-2⋅20-2⋅11-2⋅00-2⋅0032001]⎡⎢⎣1221002−2⋅12−2⋅20−2⋅20−2⋅11−2⋅00−2⋅0032001⎤⎥⎦
Bước 4.1.2
Rút gọn R2R2.
[1221000-2-4-210032001]⎡⎢⎣1221000−2−4−210032001⎤⎥⎦
[1221000-2-4-210032001]⎡⎢⎣1221000−2−4−210032001⎤⎥⎦
Bước 4.2
Multiply each element of R2R2 by -12−12 to make the entry at 2,22,2 a 11.
Bước 4.2.1
Multiply each element of R2R2 by -12−12 to make the entry at 2,22,2 a 11.
[122100-12⋅0-12⋅-2-12⋅-4-12⋅-2-12⋅1-12⋅0032001]⎡⎢
⎢⎣122100−12⋅0−12⋅−2−12⋅−4−12⋅−2−12⋅1−12⋅0032001⎤⎥
⎥⎦
Bước 4.2.2
Rút gọn R2R2.
[1221000121-120032001]⎡⎢
⎢⎣1221000121−120032001⎤⎥
⎥⎦
[1221000121-120032001]⎡⎢
⎢⎣1221000121−120032001⎤⎥
⎥⎦
Bước 4.3
Perform the row operation R3=R3-3R2R3=R3−3R2 to make the entry at 3,23,2 a 00.
Bước 4.3.1
Perform the row operation R3=R3-3R2R3=R3−3R2 to make the entry at 3,23,2 a 00.
[1221000121-1200-3⋅03-3⋅12-3⋅20-3⋅10-3(-12)1-3⋅0]⎡⎢
⎢⎣1221000121−1200−3⋅03−3⋅12−3⋅20−3⋅10−3(−12)1−3⋅0⎤⎥
⎥⎦
Bước 4.3.2
Rút gọn R3R3.
[1221000121-12000-4-3321]⎡⎢
⎢⎣1221000121−12000−4−3321⎤⎥
⎥⎦
[1221000121-12000-4-3321]⎡⎢
⎢⎣1221000121−12000−4−3321⎤⎥
⎥⎦
Bước 4.4
Multiply each element of R3R3 by -14−14 to make the entry at 3,33,3 a 11.
Bước 4.4.1
Multiply each element of R3R3 by -14−14 to make the entry at 3,33,3 a 11.
[1221000121-120-14⋅0-14⋅0-14⋅-4-14⋅-3-14⋅32-14⋅1]⎡⎢
⎢⎣1221000121−120−14⋅0−14⋅0−14⋅−4−14⋅−3−14⋅32−14⋅1⎤⎥
⎥⎦
Bước 4.4.2
Rút gọn R3R3.
[1221000121-12000134-38-14]⎡⎢
⎢⎣1221000121−12000134−38−14⎤⎥
⎥⎦
[1221000121-12000134-38-14]⎡⎢
⎢⎣1221000121−12000134−38−14⎤⎥
⎥⎦
Bước 4.5
Perform the row operation R2=R2-2R3R2=R2−2R3 to make the entry at 2,32,3 a 00.
Bước 4.5.1
Perform the row operation R2=R2-2R3R2=R2−2R3 to make the entry at 2,32,3 a 00.
[1221000-2⋅01-2⋅02-2⋅11-2(34)-12-2(-38)0-2(-14)00134-38-14]⎡⎢
⎢
⎢⎣1221000−2⋅01−2⋅02−2⋅11−2(34)−12−2(−38)0−2(−14)00134−38−14⎤⎥
⎥
⎥⎦
Bước 4.5.2
Rút gọn R2R2.
[122100010-12141200134-38-14]⎡⎢
⎢⎣122100010−12141200134−38−14⎤⎥
⎥⎦
[122100010-12141200134-38-14]⎡⎢
⎢⎣122100010−12141200134−38−14⎤⎥
⎥⎦
Bước 4.6
Perform the row operation R1=R1-2R3R1=R1−2R3 to make the entry at 1,31,3 a 00.
Bước 4.6.1
Perform the row operation R1=R1-2R3R1=R1−2R3 to make the entry at 1,31,3 a 00.
[1-2⋅02-2⋅02-2⋅11-2(34)0-2(-38)0-2(-14)010-12141200134-38-14]⎡⎢
⎢
⎢
⎢⎣1−2⋅02−2⋅02−2⋅11−2(34)0−2(−38)0−2(−14)010−12141200134−38−14⎤⎥
⎥
⎥
⎥⎦
Bước 4.6.2
Rút gọn R1R1.
[120-123412010-12141200134-38-14]⎡⎢
⎢
⎢⎣120−123412010−12141200134−38−14⎤⎥
⎥
⎥⎦
[120-123412010-12141200134-38-14]⎡⎢
⎢
⎢⎣120−123412010−12141200134−38−14⎤⎥
⎥
⎥⎦
Bước 4.7
Perform the row operation R1=R1-2R2R1=R1−2R2 to make the entry at 1,21,2 a 00.
Bước 4.7.1
Perform the row operation R1=R1-2R2R1=R1−2R2 to make the entry at 1,21,2 a 00.
[1-2⋅02-2⋅10-2⋅0-12-2(-12)34-2(14)12-2(12)010-12141200134-38-14]⎡⎢
⎢
⎢⎣1−2⋅02−2⋅10−2⋅0−12−2(−12)34−2(14)12−2(12)010−12141200134−38−14⎤⎥
⎥
⎥⎦
Bước 4.7.2
Rút gọn R1.
[1001214-12010-12141200134-38-14]
[1001214-12010-12141200134-38-14]
[1001214-12010-12141200134-38-14]
Bước 5
The right half of the reduced row echelon form is the inverse.
[1214-12-12141234-38-14]