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

Hey, can I just check these functional derivatives?:

1) [tex] \frac{\delta F[g]}{\delta g(y)}[/tex] where [tex] F[g] = \int dx \left[ \frac{1}{\sqrt{1+(g'(x))^2}} - 2g(x) + 5 \right]\>. [/tex]

2) [tex] \frac{\delta F[a,b,g]}{\delta g(y)}[/tex] where [tex] F[a,b,g] = \int d^4x \left[ A(\partial_{\mu} g(x))a(x)b(x) + Bg^3(x) \right]\>. [/tex]

2. Relevant equations

[tex] \frac{\delta F[g]}{\delta g(y)} = \lim_{\epsilon \to 0} \frac{1}{\epsilon} \left[ F[g(x) +\epsilon\delta(x-y)] - F[g(x)] \right]\>. [/tex]

3. The attempt at a solution

The answers I get are 1) -2 and 2) 3Bg^{2}(y).

Thanks in advance!

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# Homework Help: Simple Functional Derivatives

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