What are all the matrices that commute wit a matrix of ones?

In summary, the characteristics of a matrix that commutes with a matrix of ones is that the sum of every row and column is the same.
  • #1
Jamin2112
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Homework Statement



What are the characteristics of a matrix that commutes with a matrix of ones?

Homework Equations



None.

The Attempt at a Solution



I'm helping a buddy with his homework and I can't figure out this problem.
 
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  • #2
Try working it out explicitly for a 2x2 matrix (it's easy) and see if you can generalize from there.
 
  • #3
Relevant equations None.
What about the definition of "commute"?
 
  • #4
Figured out the answer, I think. The sum of every row and column is the same.
 
  • #5
Jamin2112 said:
Figured out the answer, I think. The sum of every row and column is the same.

Sounds right, can you prove it?
 
  • #6
Dick said:
Sounds right, can you prove it?

Yes, but the problem doesn't ask me to
 
  • #7
Jamin2112 said:
Yes, but the problem doesn't ask me to

Fair enough.
 

FAQ: What are all the matrices that commute wit a matrix of ones?

1. What is the definition of a matrix that commutes with a matrix of ones?

A matrix that commutes with a matrix of ones is a square matrix that, when multiplied with a matrix of ones, gives the same result regardless of the order in which the multiplication is performed.

2. How do I determine which matrices commute with a matrix of ones?

To determine which matrices commute with a matrix of ones, you can use the commutativity property, which states that two matrices A and B commute if and only if AB = BA. In other words, if the product of a matrix with a matrix of ones is equal to the product of a matrix of ones with the matrix, then the matrix commutes with the matrix of ones.

3. Can any matrix commute with a matrix of ones?

No, not all matrices can commute with a matrix of ones. For example, a matrix with only zeros in its entries will not commute with a matrix of ones because the product of the two matrices will always result in a matrix of zeros, which is not equal to the original matrix of ones.

4. Are there any special properties of matrices that commute with a matrix of ones?

One special property of matrices that commute with a matrix of ones is that they are diagonalizable. This means that they can be written in the form of a diagonal matrix, which can make certain calculations and operations easier to perform.

5. How do matrices that commute with a matrix of ones relate to linear independence?

If two matrices commute with each other, they are said to be linearly independent. This means that they cannot be written as a linear combination of each other, and they have unique properties that make them useful in various mathematical and scientific applications.

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