(computing) Any character used to specify a function of a piece of software or hardware (such as carriage return of a printer)

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

(physics) The relationship between the energy of an electron and its ability to excite an atom to a particular excited state

(mathematics) Any function in which an independent variable appears in the form of a logarithm; they are the inverse functions of exponential functions

(physics) The function governing the rate at which mechanical energy is converted to heat during viscous flow.

An electronic device used to generate a signal representing the periodic value of a given mathematical function, especially sine, square, triangle and sawtooth waveforms

(mathematics) Any function whose value may be directly calculated from the independent variable.

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

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