Understanding basics of matrices

Matrices 

A matrix is collection of numbers in form of horizontal and vertical lines is called as matrix

The above shown matrix is termed as 2x2 matrices as it contains two rows and two columns

Similarly a 3x3 matrix would be represented as

Comparable matrices:

The matrices are only comparable if columns of first matrices are equal to rows of second matrices. Then only they are comparable

Matrix A is 3 x 3 while B is 3 x 2 Matrix

If columns of first matrix are equal to rows of the second matrix then only they are comparable matrix

But if columns of first matrix are equal to rows of the second matrix then they are not comparable matrix

Equal matrix:

Two matrices A and B are equal they are of same order

Row matrix:

A matrix containing only one row

Column matrix:

A matrix containing only one column

Square matrix:

A matrix containing equal number of rows and column is a square matrix

Diagonal matrix:

A square matrix is diagonal matrix if each of its non diagonal elements are “0”

How to interpret diagonal matrix diag [2    6    8]

Scalar matrix:

A diagonal matrix is scalar if all the diagonal elements are equal

Lower triangular matrix:

A square matrix in which each of its elements above the diagonal are zero

Upper triangular matrix:

 A square matrix in which each of its elements below the diagonal are zero