How to answer matrix question 2.

Question

Given

1

2

0

3

and [1 2 0 3]

find AB and BA

Answer 1

Answer 2

if A is the four by one matrix, and B is the one by four matrix, then

AB is a four by four

1 2 0 3

2 4 0 6

0 0 0 0

3 6 0 9

BA is a one by one

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