The inverse of a symmetric matrix (if it exists) is
a symmetric matrix
a skew-symmetric matrix
a diagonal matrix
none of these
Let A be an invertible symmetric matrix.
We have AA−1=A−1A=In
⇒AA−1′=A−1A′=In′⇒A−1′A′=A′A−1′=In⇒A−1′A=AA−1′=In
A−1′=A−1 [inverse of a matrix is unique]