Some formulae and rules of operation on matrices

A matrix is a rectangular table of numbers or other mathematical objects, 

The replacement of the rows of a matrix by the corresponding columns results in a different matrix called the transpose of the initial one  

A square matrix is called sy7nmetric, if the transi osc matrix is ccjual to the original matrix  

The inverse matrix is defined if and only if A is a square matrix and the determinant of A does not vanish. A matrix satisfying these conditions is called nonsingular. A square matrix whose determinant vanishes is said to be singular. 

Definition 85 A square matrix V is called an orthogonal matrix if 

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