(mathematical analysis, algebraic geometry) A function defined by a (multivariable) implicit equation when one of the variables is regarded as the value of the function, especially where said equation is such that the value is not directly calculable from the other variables.

(mathematics) A function of two, three or n variables which is a solution to any of Laplace's equations

(mathematics) Any function that is a solution of the hypergeometric equation; usually an expansion of an hypergeometric series

(mathematics) A function whose value is always the same as its independent variable, and for which the codomain equals the domain.

(mathematics) For a given function f, another function, denoted f⁻¹, that reverses the mapping action of f; (formally) given a function f:X→Y, a function g:Y→X such that, ∀x∈X,f(x)=y⟹g(y)=x.

(mathematics) Any function, in the calculus of variations, that satisfies the Euler equations

(mathematics) A printed tabulation of selected values of a function corresponding to selected independent variables; e.g. a table of logarithms.

(mathematics) A function that assigns a pair of vertices to each edge of a graph.

(mathematics) Any generalized function which is defined by its behavior under integration.

(mathematics) Any function of a real variable whose value increases (or is constant) as the variable increases.