Matrix Multiplication (VCE SSCE General Mathematics): Flashcards

Columns in 1st must equal rows in 2nd

$m \times p$

Not commutative; generally $AB \neq BA$

1s on diagonal, 0s elsewhere (square matrix)

$AI = A = IA$

$A \times A$

Only square matrices

Run along rows of 1st, dive down columns of 2nd

Rows from 1st matrix with columns from 2nd

$A \times B$ or $AB$