If A and B are two square symmetric matrices of same order, then $AB-BA$ is |
a symmetric matrix a skew-symmetric matrix neither a symmetric nor a skew-symmetric always a diagonal matrix |
a skew-symmetric matrix |
The correct answer is Option (2) → a skew-symmetric matrix Given: $A$ and $B$ are symmetric square matrices of the same order. To find the nature of $AB - BA$, compute its transpose: $(AB - BA)^T = (AB)^T - (BA)^T = B^T A^T - A^T B^T$ Since $A$ and $B$ are symmetric, $A^T = A$ and $B^T = B$, so: $(AB - BA)^T = BA - AB = - (AB - BA)$ Therefore: $AB - BA$ is a skew-symmetric matrix. |