## Elementary Linear Algebra 7th Edition

$$A^{19}=\left[\begin{array}{ccc}{1} &{0} &{0}\\{0}& {-1}&{0}\\{0}&{0}&{1} \end{array}\right].$$
Given $$A=\left[\begin{array}{ccc}{1} &{0} &{0}\\{0}& {-1}&{0}\\{0}&{0}&{1} \end{array}\right].$$ Then, $$A^{19}=\left[\begin{array}{ccc}{1} &{0} &{0}\\{0}& {-1}&{0}\\{0}&{0}&{1} \end{array}\right],$$