How can we find functions that satisfy $f(x\cdot y)=f(x)f(y)$?
21891
If $f(xy)=f(x)f(y)$ then show that $f(x) = x^t$ for some t
74810
A function $f$ such that $f' = 0$ when $x < 0$ and $f' = 1$ when $x \geq 0$?
104278
Finding function $f(x)$ which satisfy given functional equation
64339
Find $f$ where $f'(x) = f(1+x)$
54137
Find a non-negative function on [0,1] such that $t\cdot m(\{x:f(x) \geq t\}) \to 0$ that is not Lebesgue Integrable
14975
Functions satisfying $f:\mathbb{N}\rightarrow\ \mathbb{N}$ and $f(f(n))+f(n+1)=n+2$
99917
What function satisfies $F'(x) = F(2x)$?
142873
What does the function f: x ↦ y mean?
68165
Find a function $f: \mathbb{R} \to \mathbb{R}$ that is continuous at precisely one point?
82597
How to find $ f(x)$ if $f(1-f(x))=x$ for all $x$ $\in \mathbb{R}$
31732
If the function $f$ satisfies the equation $f(xf(y)+x)=xy+f(x)$, find $f$
134043
Prove that for $ f(x+2\cdot\pi)=f(x), x \in \mathbb{R} $, there exists $ x_0 $ so $ f(x_0+\pi)=f(x_0) $
11453
Find a real function $f:\mathbb{R}\to\mathbb{R}$ such that $f(f(x)) = -x$?
29403
Finding functions $f: \Bbb R_*^+ \to \Bbb R_*^+$ with certain properties
40070
Is there a real-valued function $f$ such that $f(f(x)) = -x$?
126931
Find $f(x)$ such that $f(x)+f\left(\frac{1}{x}\right)=f(x)\cdot f\left(\frac{1}{x}\right)$
124523
Finding an Inverse Function and Composition of Functions?