The types of roles can be a rather unpleasant memory for many students who are not such fans of mathematics. The truth, however, and that the content is not very difficult, in practice, to understand the types of functions require perception and attention, without the need for complex calculations or advanced levels of mathematics itself.

To understand the types of existing functions, it is necessary to know the characteristics of each, and what the sets. Check out the quick start guide of the different types of functions, and when to identify each of them:

### As for the type classifications

The ratings on the type determine how a variable that exists in another function behaves towards her. The three types of functions are considered:

### Injector functions

The injection function is one in which an element of the domain analyzed can be associated with only one element in the image domain, how do you define a rule of it. In the injection moulding machines, however, it is possible that – despite the correlation between elements – the codomain contains elements that do not relate to the elements of the function.

That means that is a set can have three elements, while the codomain may submit five, and two of them are not part of the image of the function of the original set.

### Surjective functions

A surjective function is one in which every element of the codomain and image correspond to each other – meaning that all these elements relate to an element of the domain of the function.

It can be said that no “left” no element of the codomain, unlike injector functions. What characterizes the surjective, in this case, is the fact that an element of the image can match more than one element of the domain of the function. There may be, therefore, five elements in the domain of the function and only four elements in the image, corresponding to all of them.

### Bijection functions

The bijection functions are those that bring together injection feature and surjectives. Are injectors to the extent that all elements of the function have relationship with a single element in the picture without an element of the codomain is related to two elements of the function.

Features surjectives, however, as regards the fact that the codomain and image are identical. That means no “left” no element of the codomain relative to the image. The sum of these characteristics in a function, makes her a bijection.

### Types of functions the degree

Another way to define the types of roles is identifying the degree to which they correspond. The degree of a function is determined by the degree of power to which the elements are high. This is because the elements with different powers cannot be directly calculated among themselves, adding a layer of complexity in your resolution.

In the case of a function of the first degree, we know there is an unknown in the first degree. In the case of a function, therefore, means that the unknown is raised to the second power – or to your square – and this sorting logic follows on.