Đại số Ví dụ
[24681012120]⎡⎢⎣24681012120⎤⎥⎦
Bước 1
Nullity is the dimension of the null space, which is the same as the number of free variables in the system after row reducing. The free variables are the columns without pivot positions.
Bước 2
Bước 2.1
Multiply each element of R1R1 by 1212 to make the entry at 1,11,1 a 11.
Bước 2.1.1
Multiply each element of R1R1 by 1212 to make the entry at 1,11,1 a 11.
[22426281012120]⎡⎢
⎢⎣22426281012120⎤⎥
⎥⎦
Bước 2.1.2
Rút gọn R1R1.
[12381012120]⎡⎢⎣12381012120⎤⎥⎦
[12381012120]⎡⎢⎣12381012120⎤⎥⎦
Bước 2.2
Perform the row operation R2=R2-8R1R2=R2−8R1 to make the entry at 2,12,1 a 00.
Bước 2.2.1
Perform the row operation R2=R2-8R1R2=R2−8R1 to make the entry at 2,12,1 a 00.
[1238-8⋅110-8⋅212-8⋅3120]⎡⎢⎣1238−8⋅110−8⋅212−8⋅3120⎤⎥⎦
Bước 2.2.2
Rút gọn R2R2.
[1230-6-12120]⎡⎢⎣1230−6−12120⎤⎥⎦
[1230-6-12120]⎡⎢⎣1230−6−12120⎤⎥⎦
Bước 2.3
Perform the row operation R3=R3-R1R3=R3−R1 to make the entry at 3,13,1 a 00.
Bước 2.3.1
Perform the row operation R3=R3-R1R3=R3−R1 to make the entry at 3,13,1 a 00.
[1230-6-121-12-20-3]⎡⎢⎣1230−6−121−12−20−3⎤⎥⎦
Bước 2.3.2
Rút gọn R3R3.
[1230-6-1200-3]⎡⎢⎣1230−6−1200−3⎤⎥⎦
[1230-6-1200-3]⎡⎢⎣1230−6−1200−3⎤⎥⎦
Bước 2.4
Multiply each element of R2R2 by -16−16 to make the entry at 2,22,2 a 11.
Bước 2.4.1
Multiply each element of R2R2 by -16−16 to make the entry at 2,22,2 a 11.
[123-16⋅0-16⋅-6-16⋅-1200-3]⎡⎢
⎢⎣123−16⋅0−16⋅−6−16⋅−1200−3⎤⎥
⎥⎦
Bước 2.4.2
Rút gọn R2R2.
[12301200-3]⎡⎢⎣12301200−3⎤⎥⎦
[12301200-3]⎡⎢⎣12301200−3⎤⎥⎦
Bước 2.5
Multiply each element of R3R3 by -13−13 to make the entry at 3,33,3 a 11.
Bước 2.5.1
Multiply each element of R3R3 by -13−13 to make the entry at 3,33,3 a 11.
[123012-13⋅0-13⋅0-13⋅-3]⎡⎢
⎢⎣123012−13⋅0−13⋅0−13⋅−3⎤⎥
⎥⎦
Bước 2.5.2
Rút gọn R3.
[123012001]
[123012001]
Bước 2.6
Perform the row operation R2=R2-2R3 to make the entry at 2,3 a 0.
Bước 2.6.1
Perform the row operation R2=R2-2R3 to make the entry at 2,3 a 0.
[1230-2⋅01-2⋅02-2⋅1001]
Bước 2.6.2
Rút gọn R2.
[123010001]
[123010001]
Bước 2.7
Perform the row operation R1=R1-3R3 to make the entry at 1,3 a 0.
Bước 2.7.1
Perform the row operation R1=R1-3R3 to make the entry at 1,3 a 0.
[1-3⋅02-3⋅03-3⋅1010001]
Bước 2.7.2
Rút gọn R1.
[120010001]
[120010001]
Bước 2.8
Perform the row operation R1=R1-2R2 to make the entry at 1,2 a 0.
Bước 2.8.1
Perform the row operation R1=R1-2R2 to make the entry at 1,2 a 0.
[1-2⋅02-2⋅10-2⋅0010001]
Bước 2.8.2
Rút gọn R1.
[100010001]
[100010001]
[100010001]
Bước 3
The pivot positions are the locations with the leading 1 in each row. The pivot columns are the columns that have a pivot position.
Pivot Positions: a11,a22, and a33
Pivot Columns: 1,2, and 3
Bước 4
The nullity is the number of columns without a pivot position in the row reduced matrix.
0