Matrix operations

Patent Granted In mathematics, a matrix (plural matrices) is a rectangular array[1] of numbers, symbols, or expressions, arranged in rows and columns.[2][3] The individual items in a matrix are called its elements or entries. An example of a matrix with 2 rows and 3 columns is \begin{bmatrix}1 & 9 & -13 \\20 & 5 & -6 \end{bmatrix}. Matrices of the same size can be added or subtracted element by element. The rule for matrix multiplication, however, is that two matrices can be multiplied only when the number of columns in the first equals the number of rows in the second.