If the matrix $A=\begin{bmatrix}5 & 4a+6\\a+12 & a+3\end{bmatrix}$ is a symmetric matrix, then the value of a is :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 2
As 'A' is a symmetric matrix,
$A=A^T$
$⇒\begin{bmatrix}5 & 4a+6\\a+12 & a+3\end{bmatrix}=\begin{bmatrix}5 & a+12\\4a+6 & a+3\end{bmatrix}$
$⇒4a+6=a+12$
$⇒3a=6$
$⇒a=2$