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Question
Compute the products AB and BA whichever exists in each of the following cases:
A = [1 −1 2 3] and B=`[[0],[1],[3],[2]]`
Solution
AB=[1 −1 2 3] `[[0],[1],[3],[2]]`
⇒AB=[0+(−1)+6+6]
⇒AB=[11]
Also,
`BA = [[0],[1],[3],[2]]`[1 −1 2 3]
`⇒BA=[[0 0 0 0],[1 -1 2 3],[3 -3 6 9],[2 -2 4 6]]`
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