ABSTRACT
AI 1 2 3
2 1 0
1 0 0 0 1 0
0 0 1
2 4
3 5
(1) (1)(2) (0)(3) (0) (2) (1)(1) (0)(0) (0)
(1) (0)(2) (1)(3) (0) (2) (0)(1) (1)(0) (0)
(1) (0)(2) (0)(3) (1) (2) (0)(1) (0)(0) (0)
1 2 3
2 1 0
A: m
The last example has shown that, in general, the order in which matrices
are multiplied influences the result. To make this order perfectly clear, when speaking of matrix multiplication we say that in the matrix product AB the matrix A premultiplies B (multiplies it from the left) and that the matrix B postmultiplies A (multiplies it from the right).
