Editing Square matrix (section)

=== Identity matrix ===
The [[identity matrix]] <math>I_n</math> of size <math>n</math> is the <math>n \times n</math> matrix in which all the elements on the [[main diagonal]] are equal to 1 and all other elements are equal to 0, e.g.
<math display="block">
I_1 = \begin{bmatrix} 1 \end{bmatrix}
,\ 
I_2 = \begin{bmatrix}
         1 & 0 \\
         0 & 1 
      \end{bmatrix}
,\ \ldots ,\ 
I_n = \begin{bmatrix}
         1 & 0 & \cdots & 0 \\
         0 & 1 & \cdots & 0 \\
         \vdots & \vdots & \ddots & \vdots \\
         0 & 0 & \cdots & 1
      \end{bmatrix}.
</math>
It is a square matrix of order {{nowrap|<math>n</math>,}} and also a special kind of [[diagonal matrix]]. The term ''identity matrix'' refers to the property of matrix multiplication that
<math display=block>I_m A = A I_n = A</math> for any <math>m \times n</math> matrix {{nowrap|<math>A</math>.}}