Question

Which matrix is a diagonal matrix?

Options

• \[\begin{bmatrix}-1.1&2&0\\0&2&0\\0&0&3\end{bmatrix}\]

• \[\begin{bmatrix}1&0&3\end{bmatrix}\]

• \[\begin{bmatrix}-1.1&0&0\\0&2&0\\0&0&3\end{bmatrix}\]

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

Answer 1

The first matrix is square and each non-diagonal element is zero. Therefore, it satisfies the condition for a diagonal matrix.