Newbetuts

A bijection from the plane to itself that takes a circle to a circle must take a straight line to a straight line.

Countable-infinity-to-one function

Find all $f$ which satisfies $ f:\mathbb{R}_{\geq0} \rightarrow \mathbb{R}, f(x+y^2) \geq f(x)+y $

Function that is bijective from $(0,1)$ to $\mathbb R$ [duplicate]

How many elements can the set $S(f)=\{f(x+y)-f(x)-f(y)\ |\ x,y\in R\}$ have？

Domain of the first derivative

Find all function $f(n)$ satisfying $f(n)^2 = n f(f(n))$

Inverse function of $y=\frac{\ln(x+1)}{\ln x}$

How many nondecreasing functions $f:\{1,2, \ldots, n\} \to \{1,2, \ldots, n\}$ with $f(i)\leq i$ are there?

Set sum of graphs of linear maps is a graph only if the maps are same

The 'Square root' Function

Handy command for editing previously executed mistyped command and overwriting history entry with the fixed one

Maximal ideals in $C^\infty(\mathbb{R})$

Counting functions between two sets

Functions satisfying $f(m+f(n)) = f(m) + n$

prove that the function is surjective but not injective.

On the domain of $f(x)=\sqrt{x+2} +\frac{1}{\log_{10}(1-x) }$

New posts in functions

Is $\cos(\alpha x + \cos(x))$ periodic?

Solve $f(x+f(2y))=f(x)+f(y)+y$

Turning a Piecewise Function into a Single Continuous Expression

A bijection from the plane to itself that takes a circle to a circle must take a straight line to a straight line.

Countable-infinity-to-one function

Find all $f$ which satisfies $ f:\mathbb{R}_{\geq0} \rightarrow \mathbb{R}, f(x+y^2) \geq f(x)+y $

Function that is bijective from $(0,1)$ to $\mathbb R$ [duplicate]

How many elements can the set $S(f)=\{f(x+y)-f(x)-f(y)\ |\ x,y\in R\}$ have？

Domain of the first derivative

Find all function $f(n)$ satisfying $f(n)^2 = n f(f(n))$

Inverse function of $y=\frac{\ln(x+1)}{\ln x}$

How many nondecreasing functions $f:\{1,2, \ldots, n\} \to \{1,2, \ldots, n\}$ with $f(i)\leq i$ are there?

Set sum of graphs of linear maps is a graph only if the maps are same

The 'Square root' Function

Handy command for editing previously executed mistyped command and overwriting history entry with the fixed one

Maximal ideals in $C^\infty(\mathbb{R})$

Counting functions between two sets

Functions satisfying $f(m+f(n)) = f(m) + n$

prove that the function is surjective but not injective.

On the domain of $f(x)=\sqrt{x+2} +\frac{1}{\log_{10}(1-x) }$