(mathematics) Any function whose value is the solution of a quadratic polynomial

(mathematics) Any function whose domain is a vector space and whose value is its scalar field

(mathematics, computing) A function whose value is chosen at random from its domain / (mathematics) A function chosen at random from a set of functions

(mathematics) A function whose value is the same for all the elements of its domain.

(mathematics) Any function whose value is unchanged if the independent variable changes sign i.e. f(x) = f(-x)

(mathematics) An orthogonal function whose inner product with itself is unity

(mathematics) An ordinary trigonometric function

(algebra, logic, computing) Any function based on the operations AND, OR and NOT, and whose elements are from the domain of Boolean algebra

(mathematics) homogeneous polynomial

(mathematics) The branch of mathematics dealing with infinite-dimensional vector spaces, whose elements are actually functions, as well as generalizations such as Banach spaces and Hilbert spaces.