Matrix Multiplication: Can You Multiply a Matrix in the Middle?

In summary, the conversation is about whether or not a matrix Z can be inserted in the middle of an equation AB = BC and still maintain its validity. Some examples are discussed and it is mentioned that the proof worked out well, but the person is still wondering if they are doing it correctly. They mention relying on others for help and express their time constraints due to finals.
  • #1
EvLer
458
0
Ok, maybe a dumb question, but anyway:
if I have some matrices equation like this:

AB = BC

if I want to multiply both sides by some matrix Z can I stick it in the middle?

AZB = BZC

I know I can do these two:

ABZ = BCZ
ZAB = ZBC

but can I do the middle too?

Thanks!
 
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  • #2
Have you tried some examples to see if it works?
 
  • #3
Hurkyl said:
Have you tried some examples to see if it works?
no :biggrin:
but the proof worked out nice, so I am wondering if I am actually not doing it right.
Good point.
I just rely on the fact that people here know everything and know it off top of their heads, so it would save me trouble :biggrin:
But usually, I make an effort before I ask here. I am just pressed for time: reviewing before finals.
 
Last edited:

What is matrix multiplication?

Matrix multiplication is a mathematical operation that involves multiplying two matrices together to create a new matrix. It is a fundamental operation in linear algebra and is commonly used in various fields of science and engineering.

What are the rules for matrix multiplication?

The rules for matrix multiplication are as follows:

  • The number of columns in the first matrix must equal the number of rows in the second matrix.
  • The resulting matrix will have the same number of rows as the first matrix and the same number of columns as the second matrix.
  • To multiply two matrices, take the dot product of each row of the first matrix with each column of the second matrix.
  • The dot product is calculated by multiplying corresponding elements in each row and column, then adding the products together.

What is the difference between matrix multiplication and matrix addition?

The key difference between matrix multiplication and matrix addition is that matrix multiplication combines two matrices to create a new matrix, while matrix addition combines two matrices to create a new matrix of the same dimension. In matrix multiplication, the number of rows and columns in the resulting matrix is determined by the number of rows and columns in the two original matrices, while in matrix addition, the number of rows and columns in the resulting matrix is the same as the original matrices.

What are the applications of matrix multiplication?

Matrix multiplication has numerous applications in science and engineering. Some common examples include:

  • In computer graphics, matrix multiplication is used to rotate, translate, and scale objects.
  • In economics, matrix multiplication is used to model and analyze systems of economic relationships.
  • In physics, matrix multiplication is used to represent and solve systems of linear equations.
  • In genetics, matrix multiplication is used to analyze genetic data and identify genetic patterns.

Can any two matrices be multiplied together?

No, in order for two matrices to be multiplied together, the number of columns in the first matrix must be equal to the number of rows in the second matrix. This is known as the "multiplicability rule" and if it is not satisfied, the matrices cannot be multiplied together.

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