Solving Matrix: AX + B = CA | X + A'B = C

  • Thread starter Thread starter TranscendArcu
  • Start date Start date
  • Tags Tags
    Matrix
Click For Summary

Homework Help Overview

The discussion revolves around solving a system of matrix equations involving the expressions AX + B = CA and X + A'B = C. Participants are exploring the implications of their notation and the properties of matrix operations.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the validity of simplifying the equations directly and discussing the implications of notation, particularly regarding whether A' represents the inverse or the transpose of matrix A. There is also exploration of the steps involved in manipulating the equations to isolate X.

Discussion Status

Some participants have provided feedback on the notation and the approach taken by the original poster. There seems to be a productive exchange regarding the correct interpretation of matrix operations and notation, although no consensus has been reached on the best method to proceed.

Contextual Notes

There is a mention of potential confusion surrounding the notation used for matrices, specifically regarding the distinction between transposes and inverses, which may affect the understanding of the problem.

TranscendArcu
Messages
277
Reaction score
0

Homework Statement



Skjermbilde_2012_03_08_kl_11_13_40_AM.png


The Attempt at a Solution



I think I'm oversimplifying this problem. Why can't I just write:

AX + B =CA
X + A'B = C
X = C - A'B

?
 
Physics news on Phys.org
does your notation mean [itex]A' = A^{-1}[/itex]?

... if so, you can't do what you propse because matrix multiplication does not necesarrily commute. ionce you fix that, you're not far off the answer
 
Yes, that's what I intended my notation to convey.

Do I have to write:

AX + B = CA
AX = CA - B
A'(AX) = A'(CA - B)
IX = A'CA - A'B
X = A'CA - A'B

?
 
that looks better
 
TranscendArcu said:
AX + B =CA
X + A'B = C
X = C - A'B

lanedance said:
does your notation mean [itex]A' = A^{-1}[/itex]?

The notation A' is sometimes used to mean the transpose of matrix A. For inverses, I don't think I've ever seen ' used to indicate the inverse.

It's just as easy to write an exponent of -1 as an exponent of 2 or 3, and the intent is much clearer.

At the bottom of the input pane, click the Go Advanced button. This opens a menu of icons at the top of the input pane. The X2 button let's you write exponents, which it does by inserting [ sup ] and [ /sup ] tags (without the spaces).

You can also do this manually, like so: A[noparse]-1[/noparse]. I have inserted some other tags so that you could see the sup tags. Without those other tags, what I wrote renders like this: A-1.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K