2.34 Find the rank and the bases of the Null space for a matrix A
Problem: Find the rank and nullities of the following matrices, and find the bases of the
range space and the Null space.
\( A=\begin {pmatrix} 2 & 3 & 3 & 4 \\ 0 & -1 & -2 & 2 \\ 0 & 0 & 0 & 1 \end {pmatrix} \)
| Mathematica
mat={{2,3,3,4},
{0,-1,-2,2},
{0,0,0,1}};
{nRow,nCol} = Dimensions[mat]
|
3,4 |
Print["Rank (or dimension of the range space)=",
MatrixRank[mat]]
|
Rank (or dimension of the range space)=3
|
Print["Dimension of the Null Space=",
nCol-MatrixRank[mat]]
|
Dimension of the Null Space=1
|
Print["Basis for Null Space=",NullSpace[mat]]
|
Basis for Null Space={{3,-4,2,0}}
|
| Matlab
A=[2 3 3 4;
0 -1 -2 2;
0 0 0 1]
[nRow,nCol]=size(A);
r = rank(A);
fprintf('A range space dimension=%d\n',r);
fprintf('A null space dimension= %d\n',nCol-r);
fprintf('Basic for null space of A =');
null(A,'r')'
|
A range space dimension=3
A null space dimension= 1
Basic for null space of A =
ans =
1.5000 -2.0000 1.0000 0
|
| Maple
restart;
A:=Matrix([[2,3,3,4],[0,-1,-2,2],[0,0,0,1]]);
LinearAlgebra:-Rank(A);
LinearAlgebra:-ColumnDimension(A)-LinearAlgebra:-Rank(A);
LinearAlgebra:-NullSpace(A)
|
3
1
[3/2
-2
1
0]
|