OPERATOR

in mathematics, any symbol that indicates an operation to be performed. Ex amples are (which indicates the square root of x is to be taken) and d/dx (which indicates a differentiation with respect to x is to be performed). As a synonym for function, the word indicates the particular operation of the function, the association of a set of objects (the independent variable) with another set of objects (the dependent variable). The domain of the independent variable is mapped onto its image in the range of the dependent variable. An operator may be a transformation, map, or mapping.