Question:
If \(A=[a_{ij}]\) is an identity matrix, then which of the following is true ?
- A. \(a_{ij}=\begin{cases}0,&if~i=j\\ 1,&if~i\ne j\end{cases}\)
- B. \(a_{ij}=1,\forall i,j\)
- C. \(a_{ij}=0,\forall i,j\)
- D. \(a_{ij}=\begin{cases}0,&if~i\ne j\\ 1,&if~i=j\end{cases}\)