If X is an N vector, is it 1) possible for X*X to be negative? 2) if x*x=0, what is X.(adsbygoogle = window.adsbygoogle || []).push({});

I am having trouble writing the proper proof. for 1 I stated that it is impossible for X*X to be negative bc if x is positive, X*X is positive and if x is negative, -X*-X is still positive.

for 2 I stated the properties of multiplication; in order for a product to = 0 one of the components must be 0.

Can someone advise on the proper method for writing these proofs?

Thanks

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# Homework Help: Dot product proof

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