All $f$ such that $(\exists k)(f^\prime(x) = f(x+k))$
114307
Are Exponential and Trigonometric Functions the Only Non-Trivial Solutions to $F'(x)=F(x+a)$?
98255
Find $f(x)$ such that $f(f(x)) = x^2 - 2$
120147
For what prime numbers $p$ is $x^2+x+1$ irreducible in $\mathbb{F}_p[X]$
31698
$f(m^2 + f(n)) = f(m)^2 + n$ for all natural numbers
62966
Find all functions $f(x)$ such that $f\left(x^2+f(y)\right)$=$y+(f(x))^2$
24810
Functions satisfying $(b-a)f'(\tfrac{a+b}{2}) = f(b)- f(a)$
120960
$f,g$ such that $\int fg = \int f \int g$
24988
Prove there exists $m > 2010$ such that $f(m)$ is not prime
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} $
47162
Proving there are infinitely many primes of the form $a2^k+1.$
39090
Finding functions such that $f(g(x)) = f(x)g(x)$
28007
Assuming: $\forall x \in [0,1]:f(x) > x$ Prove: $\forall x \in [0,1]:f(x) > x + \varepsilon $
146480
Example of $\deg(fg)<\deg(f)+\deg(g)$
37183
Show that the set of all $x$ such that $x \in P$ and $x \notin Q$ exists
52530
There exists a prime congruent to $m$ mod $p$
15262
Prove $\exists \xi, \eta \in (0,1)$, such that $f(\xi)+f'(\eta)=\xi+\eta$.
135577
Prove the existence of $c$ such that $f'(c) = 2c(f(c) - f(0))$