Non-linear functional form satisfying $g(x-y) = \frac{g(x)}{g(y)}$.
11828
continuous functions on $\mathbb R$ such that $g(x+y)=g(x)g(y)$
25953
Solving a functional relation $f\left( x \cdot f(y)\right)=x^2 \cdot y^a$
90435
Prove that there exist linear functionals $L_1, L_2$ on $X$
67383
Prove that $G'$ is not planar.
76679
Prove there are no other solutions of functional equation $f(x+y) = \frac{f(x)+f(y)}{1-f(x)f(y)}$
135634
Prove that there exists a smooth map $g\colon R\to R$ such that $f(\cos(t),\sin(t))=(\cos(g(t)),\sin(g(t)))$ and satisfying $g(2π)=g(0)+2\pi q$.
78344
Nonconstant linear functional on a topological vector space is an open mapping
147299
Prove that $g(x,y) = \frac{x^3y}{x^2+y^2}$ with $g(0,0)=0$ is continuous
76458
Solve the following functional equation $f(xf(y))+f(yf(x))=2xy$
75932
Differentiability of $g:=f(\sqrt{x^2+y^2})$ for a $C^1$ function with $f'(0)=0$ NBHM $2008$
112548
Existence of non-trivial linear functional on any vector space
6680
Solve for all possible functions f: $|f(x)-f(y)|=2|x-y|$.
105497
A function satisfying a series equation
104848
What's the name of this theorem ($f>g$ given $f'>g'$ and initial value)?
39090
Finding functions such that $f(g(x)) = f(x)g(x)$
157744
Cauchy's functional equation with composite function: $gf(x+y)=gf(x)+gf(y)$
68171
Non-trigonometric Continuous Periodic Functions