If \( A=[a_{ij}]_{2\times 2} \) where \( a_{ij}=i+j+1,\ \forall\,i,j \), then \( |A| \) is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → -1
The matrix is built from \( a_{ij}=i+j+1 \), with i as the row and j as the column:
\( \displaystyle a_{11}=3,\ a_{12}=4,\ a_{21}=4,\ a_{22}=5 \)
\( \displaystyle |A|=\begin{vmatrix}3 & 4\\4 & 5\end{vmatrix} \)
\( \displaystyle =15-16=-1 \)