Commutativity and Associativity of Jordan Product

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Homework Statement


A and B are n x n matrices, so their Jordan Product is (AB + BA)/2. Show that this product is commutative but not associative.


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The Attempt at a Solution


I understand the logic behind the answer, but I don't know how to show it. Where would I start?
 
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/edit: deleted answer.

For associativity, just write out A*B and B*A and expand. For commutivity, write out A*(B*C) and (A*B)*C, and if what you get when you expand the two things is not the same, then you have shown what you wanted.
 
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JeSuisConf said:
/edit: deleted answer.

For associativity, just write out A*B and B*A and expand. For commutivity, write out A*(B*C) and (A*B)*C, and if what you get when you expand the two things is not the same, then you have shown what you wanted.
Thank you so much for the help. I figured out this question and the other Jordan Product questions from your advice.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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