New posts in functions

Demonstrate that if $f$ is surjective then $X = f(f^{-1}(X))$

What do sine, tan, cos actually mean?

Why is an ellipse, hyperbola, and circle not a function?

Integer function which takes every value infinitely often

How to represent the floor function using mathematical notation?

How is the codomain for a function defined?

Proof of linear independence of $e^{at}$

Codomain of a function

Proving that $C$ is a subset of $f^{-1}[f(C)]$

Why aren't the graphs of $\sin(\arcsin x)$ and $\arcsin(\sin x)$ the same?

How to prove if a function is bijective?

Can a function return itself or take itself as an argument?

Can differentiation be thought of as a function?$ $

can any continuous function be represented as a sum of convex and concave function?

Are the smooth functions dense in either $\mathcal L_2$ or $\mathcal L_1$?

Are two mathematically alike functions equal?

Are there any non-constant "bump functions" in "closed form" whose Fourier Transforms are also in closed form?

How to find length of a part of a curve?

Why can a circle be described by an equation but not by a function?

How prove this function $f(x)=x!-x^n$ is injective