# [Maths Class Notes] on Representation of Functions Pdf for Exam

A function may be a relation between two sets of variables such one variable depends on another variable. We can represent differing types of functions in several ways. Usually, functions are represented using formulas or graphs. We can represent the functions in four ways as given below:

Each representation has its own advantages and disadvantages. Let’s just look and try to understand.

### Different Types of Representation of functions in Maths

An example of an easy function is f(x) = x2. In this function, the function f(x) takes the given value of “x” and squares it.

For instance, if x = 3, then f(3) = 9. A few more examples of functions are: f(x) = sin x, f(x) = x2 + 3, f(x) = 1/x, f(x) = 2x + 3, etc.

There are several types of representation of functions in maths. Some important types are:

• Injective function or One to at least one of the functions: When there is mapping for a variety for every domain between two sets.

• Surjective functions or Onto function: Whenever there is more than one element is mapped from the domain to range.

• Polynomial function: The function which consists of polynomials.

• Inverse Functions: The function which inverts another function.

These were a few examples of functions. Point should be taken that there are many other functions like into function, algebraic functions, etc.

### Representation of Functions

The function is the link between the two sets and it can be represented in different ways. Consider the above example of the printing machine. The function that shows the connection between the numbers of seconds (x) and therefore the numbers of lines printed (y). We are quite conversant in functions and now we’ll find out how to represent them.

### Algebraic Representation of Function

It is one among the standard representations of functions. In this, functions are explicitly represented using formulas. The functions are generally denoted by small letter alphabet letters. For e.g. let us take the cube function.

The standard letter to represent function is f. However, it can be represented by any variable. To denote the function f algebraically i.e. using the formula, we write:

f : x → x3

where x is the variable denoting the input. It can be represented by any variable.

x3 is the formula of function

f is the name of the function

Even if it is one of the easiest ways of representing a function, it is not always easy to get the formula for the function. For such cases, we use different methods of representation.

In this method, we represent the connection within the sort of a table. For each value of x (input), there’s one and just one value of y (output). The table representation of the problem:

## Table Representation of Function

 X (Second) Y (Number of Lines) 1 100 2 130 4 160 6 190 8 220 10 250 12 280 14 310 15 325

### What is the Function Table?

A function table is a table of ordered pairs that follow the relationship, or rule, of a function. To make a function table for the example, first let us figure out the rule that shows our function. We have that every fraction of each day worked gives us that fraction of [\$] 200. Thus, if we work at some point , we get [\$] 200, because 1 * 200 = 200. If we work for two days, we get [\$] 400, because 2 * 200 = 400. If we have to work for 1.5 days, we get [\$] 300 in amount, as 1.5 * 200 = 300. Are we seeing a pattern here?

To find the entire amount of cash made at this job, we multiply the amount of days we’ve worked by 200. Thus, our rule is that we take a worth of x (the number of days worked), and that we multiply it by 200 to urge y (the total amount of money made).

A function table is used to display the rules. In the first row for the function table, we put the values of x, and in the second row of the table, we put the corresponding values of y which is according to the function rule.

 x = # days worked 1 2 3 3.5 5 7.25 8 y = total money made 200 400 600 700 1000 1450 1600

### Graphical Representation of Function

Here, we’ll draw a graph showing the connection between the 2 elements of two sets, say x and y such that x ∈ X and y ∈ Y. Putting up the satisfying points of x and y in their own axes. Drawing a line passing through these points will represent the function during a graphical way. Graphical representation of the above problem: