This online calculator can help with RREF matrix problems. Not only does it reduce a given matrix into the Reduced Row Echelon Form, but it also shows the solution in terms of elementary row operations applied to the matrix. Definitions and theory can be found below the calculator.
Reduced Row Echelon Form of a matrix
The matrix is said to be in Row Echelon Form (REF) if
- all non-zero rows (rows with at least one non-zero element) are above any rows of all zeroes
- the leading coefficient (the first non-zero number from the left, also called the pivot) of a non-zero row is always strictly to the right of the leading coefficient of the row above it (although some texts say that the leading coefficient must be 1).
Example of a matrix in REF form:
The matrix is said to be in Reduced Row Echelon Form (RREF) if
- it is in Row Echelon Form
- the leading entry in each non-zero row is a 1 (called a leading 1)
- each column containing a leading 1 has zeros everywhere else
Example of a matrix in RREF form:
Transformation to the Reduced Row Echelon Form
You can use a sequence of elementary row operations to transform any matrix to Row Echelon Form and Reduced Row Echelon Form. Note that every matrix has a unique reduced Row Echelon Form.
Elementary row operations are:
- Swapping two rows
- Multiplying a row by a non-zero constant
- Adding a multiple of one row to another row
Elementary row operations preserve the row space of the matrix, so the resulting Reduced Row Echelon matrix contains the generating set for the row space of the original matrix.
The calculator above shows all elementary row operations step-by-step, as well as their results, which are needed to transform a given matrix to RREF.