(management) Any primary business function that would affect customers or profits if interrupted

(mathematics) Any function that possesses a finite integral

(mathematics) A function which expresses numerically the loss produced by a decision or other event

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

(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

(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