If A is an invertible symmetric matrix, then $A^{-1}$ is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → a symmetric matrix
For an invertible symmetric matrix $A$, $A^T = A$.
$(A^{-1})^T = (A^T)^{-1} = A^{-1}$, hence $A^{-1}$ is also symmetric.