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Question

anonymous · Answer

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.

anonymous · Answer

you dnt hv to say
those who knw,will answer x)

anonymous · Answer

do you know what is commutative?

anonymous · Answer

Yes,sort of

anonymous · Answer

well? tell me

anonymous · Answer

It has something to do with changing the operation i think. Let me look it up quickly

anonymous · Answer

It basically means to exchange, like in addition you can do the communtative property like 5+2 = 7 and  you can switch that to 2+5= 7.

anonymous · Answer

hmm
no its fine
consider A and B be the matrix
if you say they are commutative then AB= BA
but matrix multiplication is not commutative
so
$$AB \neq BA$$

anonymous · Answer

it is aplied for all matrix multiplications except for identity matrix
the multiplication of identity matrices is commutative

anonymous · Answer

ok, that makes sense. so it only works with the identity matrix?

anonymous · Answer

if u multiply any identity matrix to a square matrix ,u will get the same

anonymous · Answer

yes

anonymous · Answer

Ok that makes perfect sense now!

anonymous · Answer

identity matrix is I
 AI = IA =A 
just gv 1 example on each :)

anonymous · Answer

Ok thank you sooo much!

anonymous · Answer

no probs