GEBRA: Representation and Operations of Matrices - FAQs

[rollcast]

I'm just revising my maths notes on matrices and I have a couple of questions, mainly about representation of matrices.

1. I have drawn the matrices in my notes with square brackets, curved brackets or straight lines and curved ends. I always just copied what the slide show or board notes had up at the time.

Is it preferable to draw matrices with one type of bracket around them compared to another?

2. When calculating the determinant of the matrix I have used delta, Δ, to represent the det. of the matrix but I can't find reference to the use of delta anywhere else?

3. When writing the inverse of a matrix I haven't divided the entities of the matrix by the determinant. I have just writing it as 1 / det. and put this in front of the matrix?

Is this correct or should I get rid of the 1/det. by multiplying it into the matrix?

Thanks
AL

 

[micromass]

I'm just revising my maths notes on matrices and I have a couple of questions, mainly about representation of matrices.

1. I have drawn the matrices in my notes with square brackets, curved brackets or straight lines and curved ends. I always just copied what the slide show or board notes had up at the time.

Is it preferable to draw matrices with one type of bracket around them compared to another?

This doesn't matter that much. All are used. However, I advize you not to use straight lines as this might be used for the determinant.

2. When calculating the determinant of the matrix I have used delta, Δ, to represent the det. of the matrix but I can't find reference to the use of delta anywhere else?

This is indeed not a common notation. Commonly, the notation det(A) is used. Using delta isn't wrong, but you must state clearly that it signifies the determinant.

3. When writing the inverse of a matrix I haven't divided the entities of the matrix by the determinant. I have just writing it as 1 / det. and put this in front of the matrix?

Is this correct or should I get rid of the 1/det. by multiplying it into the matrix?

Both are ok. However, multiplying it into the matrix is cleaner.

 

[rollcast]

Thanks Micro, I looked back and the straight line ones where determinant.

The use of delta must be set by the exam board as its used on their mark scheme solutions for matrix questions.