Finite Mathematik Beispiele
[434112302]⎡⎢⎣434112302⎤⎥⎦
Schritt 1
Schritt 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 22 by its cofactor and add.
Schritt 1.1.1
Consider the corresponding sign chart.
|+-+-+-+-+|∣∣
∣∣+−+−+−+−+∣∣
∣∣
Schritt 1.1.2
The cofactor is the minor with the sign changed if the indices match a -− position on the sign chart.
Schritt 1.1.3
The minor for a12a12 is the determinant with row 11 and column 22 deleted.
|1232|∣∣∣1232∣∣∣
Schritt 1.1.4
Multiply element a12a12 by its cofactor.
-3|1232|−3∣∣∣1232∣∣∣
Schritt 1.1.5
The minor for a22a22 is the determinant with row 22 and column 22 deleted.
|4432|∣∣∣4432∣∣∣
Schritt 1.1.6
Multiply element a22a22 by its cofactor.
1|4432|1∣∣∣4432∣∣∣
Schritt 1.1.7
The minor for a32a32 is the determinant with row 33 and column 22 deleted.
|4412|∣∣∣4412∣∣∣
Schritt 1.1.8
Multiply element a32a32 by its cofactor.
0|4412|0∣∣∣4412∣∣∣
Schritt 1.1.9
Add the terms together.
-3|1232|+1|4432|+0|4412|−3∣∣∣1232∣∣∣+1∣∣∣4432∣∣∣+0∣∣∣4412∣∣∣
-3|1232|+1|4432|+0|4412|−3∣∣∣1232∣∣∣+1∣∣∣4432∣∣∣+0∣∣∣4412∣∣∣
Schritt 1.2
Mutltipliziere 00 mit |4412|∣∣∣4412∣∣∣.
-3|1232|+1|4432|+0−3∣∣∣1232∣∣∣+1∣∣∣4432∣∣∣+0
Schritt 1.3
Berechne |1232|∣∣∣1232∣∣∣.
Schritt 1.3.1
Die Determinante einer 2×22×2-Matrix kann mithilfe der Formel |abcd|=ad-cb∣∣∣abcd∣∣∣=ad−cb bestimmt werden.
-3(1⋅2-3⋅2)+1|4432|+0−3(1⋅2−3⋅2)+1∣∣∣4432∣∣∣+0
Schritt 1.3.2
Vereinfache die Determinante.
Schritt 1.3.2.1
Vereinfache jeden Term.
Schritt 1.3.2.1.1
Mutltipliziere 22 mit 11.
-3(2-3⋅2)+1|4432|+0−3(2−3⋅2)+1∣∣∣4432∣∣∣+0
Schritt 1.3.2.1.2
Mutltipliziere -3−3 mit 22.
-3(2-6)+1|4432|+0−3(2−6)+1∣∣∣4432∣∣∣+0
-3(2-6)+1|4432|+0−3(2−6)+1∣∣∣4432∣∣∣+0
Schritt 1.3.2.2
Subtrahiere 66 von 22.
-3⋅-4+1|4432|+0−3⋅−4+1∣∣∣4432∣∣∣+0
-3⋅-4+1|4432|+0−3⋅−4+1∣∣∣4432∣∣∣+0
-3⋅-4+1|4432|+0−3⋅−4+1∣∣∣4432∣∣∣+0
Schritt 1.4
Berechne |4432|∣∣∣4432∣∣∣.
Schritt 1.4.1
Die Determinante einer 2×22×2-Matrix kann mithilfe der Formel |abcd|=ad-cb∣∣∣abcd∣∣∣=ad−cb bestimmt werden.
-3⋅-4+1(4⋅2-3⋅4)+0−3⋅−4+1(4⋅2−3⋅4)+0
Schritt 1.4.2
Vereinfache die Determinante.
Schritt 1.4.2.1
Vereinfache jeden Term.
Schritt 1.4.2.1.1
Mutltipliziere 44 mit 22.
-3⋅-4+1(8-3⋅4)+0−3⋅−4+1(8−3⋅4)+0
Schritt 1.4.2.1.2
Mutltipliziere -3−3 mit 44.
-3⋅-4+1(8-12)+0−3⋅−4+1(8−12)+0
-3⋅-4+1(8-12)+0−3⋅−4+1(8−12)+0
Schritt 1.4.2.2
Subtrahiere 1212 von 88.
-3⋅-4+1⋅-4+0−3⋅−4+1⋅−4+0
-3⋅-4+1⋅-4+0−3⋅−4+1⋅−4+0
-3⋅-4+1⋅-4+0−3⋅−4+1⋅−4+0
Schritt 1.5
Vereinfache die Determinante.
Schritt 1.5.1
Vereinfache jeden Term.
Schritt 1.5.1.1
Mutltipliziere -3−3 mit -4−4.
12+1⋅-4+012+1⋅−4+0
Schritt 1.5.1.2
Mutltipliziere -4−4 mit 11.
12-4+012−4+0
12-4+012−4+0
Schritt 1.5.2
Subtrahiere 44 von 1212.
8+08+0
Schritt 1.5.3
Addiere 88 und 00.
88
88
88
Schritt 2
Since the determinant is non-zero, the inverse exists.
Schritt 3
Set up a 3×63×6 matrix where the left half is the original matrix and the right half is its identity matrix.
[434100112010302001]⎡⎢⎣434100112010302001⎤⎥⎦
Schritt 4
Schritt 4.1
Multiply each element of R1R1 by 1414 to make the entry at 1,11,1 a 11.
Schritt 4.1.1
Multiply each element of R1R1 by 1414 to make the entry at 1,11,1 a 11.
[443444140404112010302001]⎡⎢
⎢⎣443444140404112010302001⎤⎥
⎥⎦
Schritt 4.1.2
Vereinfache R1R1.
[13411400112010302001]⎡⎢
⎢⎣13411400112010302001⎤⎥
⎥⎦
[13411400112010302001]⎡⎢
⎢⎣13411400112010302001⎤⎥
⎥⎦
Schritt 4.2
Perform the row operation R2=R2-R1R2=R2−R1 to make the entry at 2,12,1 a 00.
Schritt 4.2.1
Perform the row operation R2=R2-R1R2=R2−R1 to make the entry at 2,12,1 a 00.
[134114001-11-342-10-141-00-0302001]⎡⎢
⎢⎣134114001−11−342−10−141−00−0302001⎤⎥
⎥⎦
Schritt 4.2.2
Vereinfache R2R2.
[134114000141-1410302001]⎡⎢
⎢⎣134114000141−1410302001⎤⎥
⎥⎦
[134114000141-1410302001]⎡⎢
⎢⎣134114000141−1410302001⎤⎥
⎥⎦
Schritt 4.3
Perform the row operation R3=R3-3R1R3=R3−3R1 to make the entry at 3,13,1 a 00.
Schritt 4.3.1
Perform the row operation R3=R3-3R1R3=R3−3R1 to make the entry at 3,13,1 a 00.
[134114000141-14103-3⋅10-3(34)2-3⋅10-3(14)0-3⋅01-3⋅0]⎡⎢
⎢
⎢
⎢⎣134114000141−14103−3⋅10−3(34)2−3⋅10−3(14)0−3⋅01−3⋅0⎤⎥
⎥
⎥
⎥⎦
Schritt 4.3.2
Vereinfache R3R3.
[134114000141-14100-94-1-3401]⎡⎢
⎢
⎢⎣134114000141−14100−94−1−3401⎤⎥
⎥
⎥⎦
[134114000141-14100-94-1-3401]⎡⎢
⎢
⎢⎣134114000141−14100−94−1−3401⎤⎥
⎥
⎥⎦
Schritt 4.4
Multiply each element of R2R2 by 44 to make the entry at 2,22,2 a 11.
Schritt 4.4.1
Multiply each element of R2R2 by 44 to make the entry at 2,22,2 a 11.
[134114004⋅04(14)4⋅14(-14)4⋅14⋅00-94-1-3401]⎡⎢
⎢
⎢⎣134114004⋅04(14)4⋅14(−14)4⋅14⋅00−94−1−3401⎤⎥
⎥
⎥⎦
Schritt 4.4.2
Vereinfache R2R2.
[13411400014-1400-94-1-3401]⎡⎢
⎢⎣13411400014−1400−94−1−3401⎤⎥
⎥⎦
[13411400014-1400-94-1-3401]⎡⎢
⎢⎣13411400014−1400−94−1−3401⎤⎥
⎥⎦
Schritt 4.5
Perform the row operation R3=R3+94R2 to make the entry at 3,2 a 0.
Schritt 4.5.1
Perform the row operation R3=R3+94R2 to make the entry at 3,2 a 0.
[13411400014-1400+94⋅0-94+94⋅1-1+94⋅4-34+94⋅-10+94⋅41+94⋅0]
Schritt 4.5.2
Vereinfache R3.
[13411400014-140008-391]
[13411400014-140008-391]
Schritt 4.6
Multiply each element of R3 by 18 to make the entry at 3,3 a 1.
Schritt 4.6.1
Multiply each element of R3 by 18 to make the entry at 3,3 a 1.
[13411400014-140080888-389818]
Schritt 4.6.2
Vereinfache R3.
[13411400014-140001-389818]
[13411400014-140001-389818]
Schritt 4.7
Perform the row operation R2=R2-4R3 to make the entry at 2,3 a 0.
Schritt 4.7.1
Perform the row operation R2=R2-4R3 to make the entry at 2,3 a 0.
[134114000-4⋅01-4⋅04-4⋅1-1-4(-38)4-4(98)0-4(18)001-389818]
Schritt 4.7.2
Vereinfache R2.
[1341140001012-12-12001-389818]
[1341140001012-12-12001-389818]
Schritt 4.8
Perform the row operation R1=R1-R3 to make the entry at 1,3 a 0.
Schritt 4.8.1
Perform the row operation R1=R1-R3 to make the entry at 1,3 a 0.
[1-034-01-114+380-980-1801012-12-12001-389818]
Schritt 4.8.2
Vereinfache R1.
[134058-98-1801012-12-12001-389818]
[134058-98-1801012-12-12001-389818]
Schritt 4.9
Perform the row operation R1=R1-34R2 to make the entry at 1,2 a 0.
Schritt 4.9.1
Perform the row operation R1=R1-34R2 to make the entry at 1,2 a 0.
[1-34⋅034-34⋅10-34⋅058-34⋅12-98-34(-12)-18-34(-12)01012-12-12001-389818]
Schritt 4.9.2
Vereinfache R1.
[10014-341401012-12-12001-389818]
[10014-341401012-12-12001-389818]
[10014-341401012-12-12001-389818]
Schritt 5
The right half of the reduced row echelon form is the inverse.
[14-341412-12-12-389818]