Answers for Ex 3.10 question 2

[MTDTMFH]

Hi Mike

Not sure if this is the best place but I can't seem to find the answers showing the proofs for Exercises 3.10 Q2.

Struggling to unwind some of these equations to prove equality. Been battling with 2b for sometime now. And I'm sure I'm going to hit some walls down the track too...

If they are not available I will post on mathoverflow or something...

Many thanks in advance!

MH

[mikexcohen]

Hi MH. Sure, you can post questions here if you like. I normally direct people to discuss.sincxpress.com, but I get questions on many different platforms... Anyway, the key insight here is that both vectors are unit length. So if you end up with a term x'x, then you simply set it to 1. To solve 2b, you have to write out |x-y| as (x-y)^T(x-y). Then you expand the dot product multiplications (x'x - x'y....) and simplify when possible. I hope that hint helps. If you need more hints, please show what you've done so far so I can give feedback on that.

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On Thu, Apr 21, 2022 at 3:55 AM MTDTMFH ***@***.***> wrote: Hi Mike Not sure if this is the best place but I can't seem to find the answers showing the proofs for Exercises 3.10 Q2. Struggling to unwind some of these equations to prove equality. Been battling with 2b for sometime now. And I'm sure I'm going to hit some walls down the track too... If they are not available I will post on mathoverflow or something... Many thanks in advance! MH — Reply to this email directly, view it on GitHub <#8>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ARKKLI2OTNZQKG2AIPMQ4VDVGCYPHANCNFSM5T5YLPGQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

-- Mike X Cohen, PhD Fresh look: mikexcohen.com

[MTDTMFH]

Thank you so much, I see where I was going wrong now!

I will have a look at the discussion site in the future too before posting :)

Best wishes
MH