In general, matrix multiplication is not commutative. Show by counterexample that this is true. Then give an example of when matrix multiplication is commutative. Explain.

Question

anonymous · Answer

@Mertsj Please help!

mertsj · Answer

Yes.  You could multiply those and then switch the order, multiply again and show that the results are not the same and therefore matrix multiplication is not commutative.

anonymous · Answer

So how about disproving it?

anonymous · Answer

When would the commutative property work?

mertsj · Answer

You can't disprove something that is true.

mertsj · Answer

When you are multiplying two inverse matrices.

anonymous · Answer

Or wait, so there is no example that shows marix multiplication is commutative?

mertsj · Answer

I don't think think those two are inverses.

mertsj · Answer

|dw:1367452967838:dw|