How can we find a function such that $f'(x)=f(x+1)$?
36302
How to solve differential equations of the form $f'(x) = f(x + a)$
129579
If $f''(x_0)$ exists then $\lim_{x \to x_0} \frac{f(x_0+h)-2f(x_0)+f(x_0-h)}{h^2} = f''(x_0)$
105319
A calculus problem with functions such that $f''(x) = g(x)$ and $g''(x) = f(x)$
55286
Functional equation: $f: \mathbb{R} \rightarrow \mathbb{R}$, $f((x + 1) f(y)) = y (f(x) + 1)$
105999
An application of derivatives problem- to show that $f(x+2)-f(x)>2$ for $f(x)=x\cos(1/x)$
40070
Is there a real-valued function $f$ such that $f(f(x)) = -x$?
11453
Find a real function $f:\mathbb{R}\to\mathbb{R}$ such that $f(f(x)) = -x$?
59063
$f(f(x))=f(x)$ question
53024
$f(x)f(1/x)=f(x)+f(1/x)$
139019
Polynomial satisfying $f(x) = f'(x) \cdot f''(x)$
151519
If $f(f(x))=x^2-x+1$, what is $f(0)$?
23222
If $f(x) + f'(x) + f''(x) \to A$ as $x \to \infty$, then show that $f(x) \to A$ as $x \to \infty$
13202
Prove that there exists at least one $x_0\in\mathbb{R}$, such that $f(x_0)+f''(x_0)=0$
129052
Find all functions satisfying $\frac{1}{f(a)}+ \frac{1}{f(b)} = \frac{1}{f(c)} $ whenever $\frac{1}{a}+ \frac{1}{b} = \frac{1}{c} $
4065
What are the entire functions $f$ such that $|f'(z)| \leq |f(z)| \ ? $
107727
$m\{x\in [0,1]:f'(x)=0\}>0$
81720
$f(x) + f(x+f(y)) = y + f(f(x) + f(f(y)))$