A function satisfying $f \left ( \frac 1 {f(x)} \right ) = x$
47166
Is there a function whose inverse is exactly the reciprocal of the function, that is $f^{-1} = \frac{1}{f}$?
158888
Prove that the function $f(x)=\frac{x}{x^2+1}$ is continuous at $x=-1$.
61670
Proving that $(b_n) \to b$ implies $\left(\frac{1}{b_n}\right) \to \frac{1}{b}$
28286
About finding the function such that $f(xy)=f(x)f(y)-f(x+y)+1$
17343
Function on $[a,b]$ that satisfies a Hölder condition of order $\alpha > 1 $ is constant
104278
Finding function $f(x)$ which satisfy given functional equation
1582
$f(x+1)-f(x)$ converges $\Rightarrow\frac{f(x)}x$ converges
54830
Find the limit $\lim\limits_{x\to\infty} f(x)= \lim\limits_{x \to \infty} \left(\frac{x}{x+1}\right)^x$
35556
$f(z)=\frac{z}{1+|z|} $ Is 1-1?
44293
Functions satisfying $f\left( f(x)^2+f(y) \right)=xf(x)+y$
142928
Proving $\left\{ \frac{1}{n} \right\}$ is Cauchy
132093
Solve $f(f(x))=f(x)$
8913
Show that there is $\xi$ s.t. $f(\xi)=f\left(\xi+\frac{1}{n}\right)$
62966
Find all functions $f(x)$ such that $f\left(x^2+f(y)\right)$=$y+(f(x))^2$
98768
Prove $\left(1+\frac{x}{n}\right)^n < e^x$, where $x$ is any positive real number and $n$ is any positive integer.
409
functions satisfying $f(x - y) = f(x) f(y) - f(a - x) f(a + y)$ and $f(0)=1$
88683
Functional equation $f\left(\frac{x+y}{2}\right)+f\left(\frac{2xy}{x+y}\right)=f(x)+f(y)$ implies $2f(\sqrt{xy})=f(x)+f(y)$