Reduced Row Echelon Form

Definition

Reduced row echelon form is a special type of matrix where the leading entry in each row is 1, and all other entries in that column are 0. This form is particularly useful when solving systems of linear equations using matrices, as it allows for the efficient identification of the solutions.

5 Must Know Facts For Your Next Test

1. Reduced row echelon form is a unique representation of a matrix, and it can be obtained from the row echelon form by performing additional row operations.
2. The reduced row echelon form of a matrix is the simplest possible form that still retains all the information about the original matrix.
3. The number of non-zero rows in the reduced row echelon form of a matrix is equal to the rank of the matrix.
4. The reduced row echelon form of a matrix can be used to determine the solutions of a system of linear equations, as the variables corresponding to the free columns are the parameters of the solution.
5. Reduced row echelon form is a crucial step in the process of solving systems of equations using matrices, as it simplifies the matrix and makes the solutions more easily identifiable.

Review Questions

• Explain how the reduced row echelon form of a matrix is obtained from the row echelon form.
  • To obtain the reduced row echelon form of a matrix from the row echelon form, additional row operations are performed. Specifically, the leading 1 in each row is made the only non-zero entry in that column by subtracting appropriate multiples of that row from the other rows. This process ensures that the leading entry in each row is 1, and all other entries in that column are 0, resulting in the reduced row echelon form of the matrix.
• Describe the relationship between the rank of a matrix and the number of non-zero rows in its reduced row echelon form.
  • The number of non-zero rows in the reduced row echelon form of a matrix is equal to the rank of the matrix. This is because the rank of a matrix represents the number of linearly independent rows or columns in the matrix, and the reduced row echelon form preserves this information while simplifying the matrix. The reduced row echelon form can, therefore, be used to determine the rank of a matrix, which is an important concept in solving systems of linear equations using matrices.
• Explain how the reduced row echelon form of a matrix can be used to identify the solutions of a system of linear equations.
  • The reduced row echelon form of a matrix can be used to efficiently identify the solutions of a system of linear equations. The variables corresponding to the free columns (columns with a leading entry of 0) in the reduced row echelon form are the parameters of the solution, while the variables corresponding to the pivot columns (columns with a leading entry of 1) can be expressed in terms of the free variables. This allows for the identification of the particular solution and the general solution of the system of linear equations, making the reduced row echelon form a crucial tool in solving systems of equations using matrices.

Related terms

Row Echelon Form: A matrix is in row echelon form if the leading entry in each row is 1, and all entries below it in that column are 0.

Gaussian Elimination: A method used to transform a matrix into row echelon form by performing elementary row operations.

Augmented Matrix: A matrix formed by combining the coefficient matrix and the constant terms of a system of linear equations.