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which is true? Please explain the meaning of each question and the answer. (I pu

ID: 3078333 • Letter: W

Question

which is true? Please explain the meaning of each question and the answer. (I put the answer on the HWwebsite that #4&6 are true, but thoes choices were wrong... there is few more true or 4 or 6 is wrong..) #1. If "A" is an "m*n" matrix and if the equation Ax = b is inconsistent for some b in R^m, then "A" cannot have a pivot position in every row. #2. If the equation Ax = b is inconsistent, then "b" is not in the set spanned by the columns of "A". #3. The solution set of a linear system whose augmented matrix is[a1 a2 a3 | b] is the same as the solution set of Ax = b , if A = [a1 a2 a3]. #4. Every matrix equation Ax = b corresponds to a vector equation with the same solution set. #5. The equation Ax = b is consistent if the augmented matrix [A | b] has a pivot position in every row. #6. If the augmented matrix [A | b] has a pivot position in every row, then the equation Ax = b is inconsistent.

Explanation / Answer

1.False; If A has a pivot position in every row, then Ax = b is consistent. 2.false; its true at this condition This is about the equivalence, again. More precisely, you can write the matrix equation as a vector equation x1a1+ +xnan = b. Since the matrix equation is consistent, 3.TRue 4.true 5.False; Be careful. If the last column of the augmented matrix has a pivot position, then the system (as well as the matrix equation) is inconsistent. Note that if, however, the coefficient matrix A has a pivot position in every row, then the last column of the augmented matrix cannot have a pivot position, and hence the system is consistent