$$f(x)=0$$

In mathematics, a function is a rule or relationship that assigns each input (typically denoted as "x") to a unique output (typically denoted as "f(x)"). It describes how elements from one set (the domain) correspond to elements in another set (the codomain or range). Functions are fundamental in mathematics and are used to model relationships between variables, analyze transformations, and solve equations. They are represented as equations, graphs, or tables and play a crucial role in various mathematical concepts and applications.