Which one of the following is a scalar matrix ? A. ((1,1),1,1))

Question

Which one of the following is a scalar matrix ?

A. \(\begin{pmatrix} 1&1 \\ 1 &1 \end{pmatrix}\)

B.\(\begin{pmatrix} 6&0 \\ 0 &3 \end{pmatrix}\)

C.\(\begin{pmatrix} -8&0 \\ 0 &-8 \end{pmatrix}\)

D. None of these

Answer 1

= \(\begin{pmatrix} -8&0 \\ 0 &-8 \end{pmatrix}\)

= - 8\(\begin{pmatrix} 1&0 \\ 0 &1 \end{pmatrix}\)

Since - 8 could be taken common from each row or column. Hence C is a scalar matrix.