(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Hi all,

I need help proving the result:

Let g(x) = x'Mx, where M is a n-by-n real constant matrix and x' denotes the transpose of vector x. Then the derivative of g(x) = (M + M')x.

3. The attempt at a solution

I was thinking of using product rule on x'(Mx) to get Mx + x'M, but apparently this is incorrect as the dimensions of Mx and x'M don't even match and so cannot be grouped together to get (M + M')x.

Please help.

Thank you.

Regards,

Rayne

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# Homework Help: Matrix/Vector differentiation

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