Câu 21:
Cho $A = \left[ {\begin{array}{*{20}{c}}1&1\\0&1\end{array}} \right]\left[ {\begin{array}{*{20}{c}}2&0\\0&3\end{array}} \right]\left[ {\begin{array}{*{20}{c}}1&{ - 1}\\0&1\end{array}} \right]$. Biết ${\left[ {\begin{array}{*{20}{c}}a&0\\0&b\end{array}} \right]^n} = \left[ {\begin{array}{*{20}{c}}{{a^n}}&0\\0&{{b^n}}\end{array}} \right](n \in {N^ + })$. Tính A3?
Câu 21:
Cho A = \left[ {\begin{array}{*{20}{c}}1&1\\0&1\end{array}} \right]\left[ {\begin{array}{*{20}{c}}2&0\\0&3\end{array}} \right]\left[ {\begin{array}{*{20}{c}}1&{ - 1}\\0&1\end{array}} \right]. Biết {\left[ {\begin{array}{*{20}{c}}a&0\\0&b\end{array}} \right]^n} = \left[ {\begin{array}{*{20}{c}}{{a^n}}&0\\0&{{b^n}}\end{array}} \right](n \in {N^ + }). Tính A3?