Question

6．若矩阵A=$[\begin{array}{l}{1}&{2}\\{3}&{4}\end{array}]$，B=$[\begin{array}{l}{4}&{3}\\{2}&{1}\end{array}]$，则AB=$[\begin{array}{l}{8}&{5}\\{20}&{13}\end{array}]$．

Answer 1

分析 根据矩阵的乘法，即可求得AB．

解答 解：根据矩阵的乘法AB=$[\begin{array}{l}{1}&{2}\\{3}&{4}\end{array}]$$[\begin{array}{l}{4}&{3}\\{2}&{1}\end{array}]$=$[\begin{array}{l}{8}&{5}\\{20}&{13}\end{array}]$，
∴AB=$[\begin{array}{l}{8}&{5}\\{20}&{13}\end{array}]$，
故答案为：$[\begin{array}{l}{8}&{5}\\{20}&{13}\end{array}]$．

点评 本题考查矩阵的乘法，考查计算能力，属于基础题．