(mathematics) An ordinary trigonometric function

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

(physics) A relationship that describes the probability of a particle that collides with another being scattered in any particular manner

(astronomy) A function that describes the angular distribution of light reflected from a body when illuminated from a specific direction

(mathematics) Any function whose values are points

(computing) Any of a set of subroutines that perform standard mathematical functions included in a programming language; either included in a program at compilation time, or called when a program is executed

(mathematics) A function where the independent variable is raised to a particular real number power.

(mathematics) A function that gives the relative probability that a discrete random variable is exactly equal to some value.

(mathematics) Any function that applies constraints to a maximum or minimum problem

(mathematics) Either of a pair of functions whose inner product is zero