Short Quiz

If \(\mathrm{A}^{2}=4 \mathrm{~A}+3 \mathrm{I}\) and \(\mathrm{A}^{-1}=\mathrm{xA}+\mathrm{yI}\), then the value of \((\mathrm{x}+\mathrm{y})\) is :

Assertion (A) : Every scalar matrix is a diagonal matrix.
Reason (R) : In a diagonal matrix, all the diagonal elements are 0 .

If \(A=\left[a_{i j}\right]\) is an identity matrix, then which of the following is true ?

Assertion (A) : A=diag [ \(\begin{array}{lll}3 & 5 & 2\end{array}\) is a scalar matrix of order \(3 \times 3\).
Reason (R) : If a diagonal matrix has all non-zero elements equal, it is known as a scalar matrix.