Question

For a matrix $A,AI=A$ and $A{A}^T=I$ is true

• A. If $A$ is a square matrix
• B. If $A$ is a non-singular matrix
• C. If $A$ is a symmetric matrix
• D. If $A$ is any matrix

Answer 1

The correct option is A If $A$ is a square matrix

$\begin{array}{c}ForamatrixA,AI=A,A{A}^T=I\\ Then,Aissquarematrix.\end{array}$