Name of a matrix with one column and row removed

Question

I am looking for the exact name of a matrix where the i-th column and rows have been removed.

I cannot remember how it is named in linear algebra, does anyone got an idea?

Thanks!

Answer 1

This is called the cofactor matrix of $a_{j,j}$. "Cofactor" refers to the result after deletion, and itself is used to refer to the determinant. Cofactor matrix is a derived name from that.

Answer 2

If you are talking about the determinant, the term is minor.

https://en.wikipedia.org/wiki/Minor_(linear_algebra)

Answer 3

A matrix with certain rows and columns removed is called submatrix

https://nptel.ac.in/courses/122104018/node10.html

Answer 4

You might be looking for submatrix (or possibly principal submatrix)? Or you might be thinking of the minor, which is the determinant of the thing you are describing, although it doesn't assume that the same-indexed row and column were removed.

Answer 5

you might be referring to:

1. Submatrix

2. the minor - wikipedia - Minor

3. a matrix shape resulting from a Gaussian elimination Reduced row echelon form