Here is some mathematica code to be used by my linear algebra students. The post will be periodically updated as the course progresses.
Entering matrices
Mathematica views matrices as lists of columns. Thus to enter the matrix
we type in
mat = {{1, 1, -1, -1}, {1, 2, 3, 4}, {1, 3, 5, 7}};
and hit [enter]. Here we have given the matrix the name mat
and suppressed the output.
To view the matrix, type in the code
MatrixForm[mat]
and hit [enter].
Row reducing a matrix
To row reduce the matrix, type in the code
RowReduce[mat]
and hit [enter]. Notice that the output is just given in list format. To display the result as a matrix, you can use either
MatrixForm[RowReduce[mat]]
or
RowReduce[mat] // MatrixForm