CEVAP:

Although the range and the image of a function are two concepts that need to be distinguished, we still know that they are closely related. The image is always a subset of the range. Yet, there are functions for which the range and the image sets are exactly the same. Thus, given a function f : A › B if the image is equal to the range, i.e. f (A)=B the function f is called surjective (onto). Equivalently, for every element b of the set B if there can be found an element a of A such that f (a)=b, then f is called onto.