Question

If $A$ is a square matrix of order $m$, then the matrix $B$ of same order is called the inverse of the matrix $A$, if

• A. AB = A
• B. BA = A
• C. AB = BA = I
• D. AB = -BA

Answer 1

Answer: (C)

If $A$ is a square matrix of order $m$, and if there exists another square matrix $B$ of the same order $m$, such that $AB=BA=I$, then $B$ is called the inverse matrix of $A$. In this case $A$ is said to be invertible.