# Matrix question

1. Feb 5, 2006

### Mathman23

Hi

I got a question regarding a matrix expression:

Let $$X \in Mat_{n,n} (\mathbf{F})$$. Then I'm suppose to show AX = XA for all $$A \in Mat_{n,n} \mathbf{(F)}$$ if and only if $$s \in \mathbf{F}$$

/Fred

Last edited: Feb 5, 2006
2. Feb 5, 2006

### HallsofIvy

Staff Emeritus
Did you miswrite something? What matrix expression?

3. Feb 6, 2006

### Mathman23

No, It is correctly typed.

/Fred

4. Feb 6, 2006

### matt grime

You did mistype something. s appears in the last three symbols and nowhere before, and the X vanishes from the question.

Last edited: Feb 6, 2006
5. Feb 6, 2006

### HallsofIvy

Staff Emeritus
When I first looked at it there was no matrix expression! May have been the server was slow in loading the LATEX. However, as Matt said, "if and only if $$s \in \mathbf{F}$$ makes no sense as there is no "s" in the hypothesis.