What a Matrix Tells Us

Complete the chart below given that: A is an m x n matrix with p pivot columns, b is m x 1 vector

Condition
m < n
m = n
m > n

Show an example of this condition, using - for entries, such as

- - - 
- - -  

for a 2x3 matrix.





Maximum number of pivot columns       
Maximum number of pivot rows       
p= number of pivot columns if p=m if p<m if p=m if p<m if p=n if p<n
1. Number of solutions of Ax=0
.
 1a 1b
1c  1d  1e  1f
2. Number of solutions of Ax=b
where [A|b] has p pivot columns. (Remember, A has p pivot columns).
 2a  2b  2c  2d  2e  2f
3. Number of solutions of Ax=b
where  [A|b] has p+1 pivot columns
(Remember, A has p pivot columns).
 3a  3b  3c  3d  3e  3f
4. Is b is in Span{columns of A} for all possible b's? .  4a  4b  4c  4d  4e  4f
5. Do columns of A span R^m? 

.

 5a  5b  5c  5d  5e  5f
6. Is {Columns of A}  linearly independent?

.

 6a  6b  6c  6d  6e  6f

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