(mathematics) Any function whose graph is a straight line: f(x)=ax+b

(computing) Any of a set of subroutines supplied with a language or system that can be called to perform standard mathematical functions efficiently

(logic, mathematics) A function that is equivalent to the NOT operator.

(astronomy) A relative measure of the relationship between stellar magnitude and the distribution of stars between magnitudes

(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