List of functions with $f(x)=\dfrac{d\,f(x)}{dx}$ like $f(x)=0$ or $f(x)=e^x$
10431
Prove that $C\exp(x)$ is the only set of functions for which $f(x) = f'(x)$
109942
Find continuous functions such that $f(x+y)+f(x-y)=2[f(x)+f(y)]$
5419
Continuous functions with $f^2(x)=g^2(x)\neq 0$
26677
thoughts about $f(f(x))=e^x$
100378
Are there "All" and "Any" functions in Mathematica?
10068
$f(x,y)= e^{-\frac{1}{x^2+y^2}}$ when $(x,y)\neq (0,0)$ and $f(0,0)=0$.
74810
A function $f$ such that $f' = 0$ when $x < 0$ and $f' = 1$ when $x \geq 0$?
52858
Find $f$ if $ f(x)+f\left(\frac{1}{1-x}\right)=x $
47166
Is there a function whose inverse is exactly the reciprocal of the function, that is $f^{-1} = \frac{1}{f}$?
94944
Differentiable functions satisfying $f'(f(x))=f(f'(x))$
56827
Functions that are their Own nth Derivatives for Real $n$
103568
Possibility of finding a such function?
122519
Multiplicative Functions
64339
Find $f$ where $f'(x) = f(1+x)$
24810
Functions satisfying $(b-a)f'(\tfrac{a+b}{2}) = f(b)- f(a)$
106853
Find all functions: $\left ( \int \frac{dx}{f(x)} \right )\left ( \int f(x)dx \right )=c$
4065
What are the entire functions $f$ such that $|f'(z)| \leq |f(z)| \ ? $