How can I prove/understand the following functional derivative?
114021
Inverse Green's Function identity in derivation of Hedin's equations
12172
help me understand derivatives and their purpose
28888
The functional $I[w] = \int_U \frac{1}{2} |Dw|^2 - fw \, dx$ is weakly lower semicontinuous
80471
Derivative of $(y-XB)' h(y-XB)$ with respect to $B$
124499
Where is the error in my proof that all derivatives are continuous?
54321
Questions about $f: \mathbb{R} \rightarrow \mathbb{R}$ with bounded derivative
75216
What is the derivative of this?
72702
Estimate on the derivative at fixed point
105068
Proving that the function is differentiable and $f'(0)=0$
71599
How to prove useful property of logarithm of generating functional in QFT?
85623
Proof of continuity implied by differentiability
90435
Prove that there exist linear functionals $L_1, L_2$ on $X$
115635
Differentiability of antiderivative and continuity of derivative
84318
A problem with the functional $F(\chi) = \int_{\mathbb{R}}(\chi'^2+\chi^2(1-\chi)^2)dx$.
13086
Overview of basic facts about Cauchy functional equation
26113
Proving the functional equation $\theta (x) = x^{-\frac{1}{2}} \theta (x^{-1})$ from the Poisson summation formula
151109
Verification that $\lim_{x \to a}\frac{f(x)-f(a)}{x-a}$ and $\lim_{h\to 0}\frac{f(a+h) -f(a)}{h}$ are equivalent definitions of the derivative.