1. ## simple matrix question

simple matrix question

For Matrix A; size (3 x 1)
Matrix B; size (1 x 3)

AB = (3 x 3)

But when does matrix multiplication not work

2. Hello

The product AB is not defined if the number of columns of A is different from the number of rows of B. For example, you can not evaluate AB with A and B of size 3x1.

Cheers