Zero Matrix

Definition

A matrix whose entries are all zero is called a zero matrix.

Usually denoted as $0$, or if the sizes are important, $0_{m\times n}$.

Example

$$\left[\begin{array}{c}0\end{array}\right],\left[\begin{array}{cc}0& 0\\ 0& 0\end{array}\right],\left[\begin{array}{ccc}0& 0& 0\\ 0& 0& 0\\ 0& 0& 0\end{array}\right]$$