Question

Under which condition on the set A of order m x n and set B of order k x l, be so that AB and BA exist.​

Answer 1

Answer:

Let A = [aij]m×n and B = [bij]p×q

∴ B'=[bij]p×q

Now, AB' is defined, so n = q

and B'A is also defined, so p = m

∴ order of B is m × n