Question

Which matrix is a scalar matrix?

Options

• \[\begin{bmatrix}\sqrt{3}&0&0\\0&2&0\\0&0&\sqrt{3}\end{bmatrix}\]

• \[\begin{bmatrix}1&0&1\\0&1&0\\0&0&1\end{bmatrix}\]

• \[\begin{bmatrix}\sqrt{3}&0&0\\0&\sqrt{3}&0\\0&0&\sqrt{3}\end{bmatrix}\]

• \[\begin{bmatrix}0&0&0\\0&0&0\\0&0&0\end{bmatrix}\]

Answer 1

All non-diagonal elements in the first matrix are zero. Every diagonal position contains the same value, \[\sqrt{3}\].