In: Math
1----
. Is the statement "Elementary row operations on an augmented matrix never change the solution set of the associated linear system" true or false? Explain.
A.
True, because elementary row operations are always applied to an augmented matrix after the solution has been found.
B.
False, because the elementary row operations make a system inconsistent.
C.
True, because the elementary row operations replace a system with an equivalent system.
D.
False, because the elementary row operations augment the number of rows and columns of a matrix.
2---
Indicate whether the statements given in parts (a) through (d) are true or false and justify the answer.
a. Is the statement "Every elementary row operation is reversible" true or false? Explain.
A.
False, because only interchanging is a reversible row operation.
B.
True, because interchanging can be reversed by scaling, and scaling can be reversed by replacement.
C.
False, because only scaling and interchanging are reversible row operations.
D.
True, because replacement, interchanging, and scaling are all reversible.
3----
In parts (a) through (e) below, mark the statement True or False. Justify each answer.
a. The echelon form of a matrix is unique. Choose the correct answer below.
A.
The statement is true. The echelon form of a matrix is always unique, but the reduced echelon form of a matrix might not be unique.
B.
The statement is true. Neither the echelon form nor the reduced echelon form of a matrix are unique. They depend on the row operations performed.
C.
The statement is false. The echelon form of a matrix is not unique, but the reduced echelon form is unique.
D.
The statement is false. Both the echelon form and the reduced echelon form of a matrix are unique. They are the same regardless of the chosen row operations.