Chapter 3 - Matrices - 3.1 Matrix Operations - Exercises 3.1 - Page 152: 17

$$A=\left[\begin{array}{r}{0}&{1} \\ {0}&{0} \end{array}\right]$$

One can see that the matrix $A$ $$A=\left[\begin{array}{r}{0}&{1} \\ {0}&{0} \end{array}\right]$$ is non zero and $$A^2=AA=\left[\begin{array}{r}{0}&{1} \\ {0}&{0} \end{array}\right]\left[\begin{array}{r}{0}&{1} \\ {0}&{0} \end{array}\right]=\left[\begin{array}{r}{0}&{0} \\ {0}&{0} \end{array}\right].$$