functions

Following our normal procedure to solve this type of exercise, we start with the definitions. Definition: “A function f from A to B is called onto, or a surjection, if and only if for every element b∈B there is an element a∈A with f(a)=b. A function f is called surjective if it is onto.” Discrete […]

Note that in each case, to find the domain, determine the set of elements assigned values by the function. As you should know by now, we need to always start with the definitions. Definition: “If f is a function from A to B, we say that A is the domain of f and B is

When solving exercises related to functions, a common type of problem is to find out if what we are given is actually a function or not. As with almost everything in mathematics, we need to start with the definition. Definition: “Let A and B be nonempty sets. A function f from A to B is