Which of the following is a diagonal matrix?

Question

Accepted Answer

C. $\begin{bmatrix}4&0&0\0&-1&0\0&0&2\end{bmatrix}$

In a diagonal matrix, every non-diagonal entry must be zero.
Option C satisfies this exactly.
Although the zero matrix in option B also has all off-diagonal entries zero, the chapter separately defines zero/null matrix
the clearest standard example of a diagonal matrix here is option C.

Answer

$\begin{bmatrix}1&2\0&3\end{bmatrix}$

Answer

$\begin{bmatrix}0&0\0&0\end{bmatrix}$

Answer

$\begin{bmatrix}1&1\1&1\end{bmatrix}$

Which of the following is a diagonal matrix?

Keep practising Unit 8B: Volumes of Revolution and Cross-Sections