Functions involving real values
34223
Prove that every function that verifies $|f(x)-f(y)|\leq(x-y)^2$ for all $x,y$ is constant.
103568
Possibility of finding a such function?
99827
For what values will f(x) be necessarily one-one?
28011
Does there exists an entire function such that for each $|z|>C$ for some constant $C$, $|f(z)|=|z|+1$?
56827
Functions that are their Own nth Derivatives for Real $n$
1440
Are the any non-trivial functions where $f(x)=f'(x)$ not of the form $Ae^x$
89257
Give an example of a function $f:\mathbb{R}^2 \mapsto \mathbb{R}^2$ such that
156778
Finding functions satisfying $f(f(x))+f(x)+x=0$
97371
Proving a function is constant, under certain conditions?
11453
Find a real function $f:\mathbb{R}\to\mathbb{R}$ such that $f(f(x)) = -x$?
92638
Approximation of measurable function by simple functions
62817
Functions which are Continuous, but not Bicontinuous
40070
Is there a real-valued function $f$ such that $f(f(x)) = -x$?
8255
Real polynomials from repunits to repunits ( Putnam 2007 A4)
47611
Integers and integer functions
153969
The "elements" of a real number
75882
Countability of local maxima on continuous real-valued functions