Showing posts with label Functions. Show all posts
Showing posts with label Functions. Show all posts

Friday, February 22, 2013

Examples of Functions

Introduction to examples of functions:

A function is a special type of relation. In a function, no two ordered pairs can have the same initial element and a different second element. That is, for a function, corresponding to each first element of the ordered pairs, there must be a different second element. i.e. In a function we cannot have ordered pairs of the form (a1, b1) and (a2, b2) with a1 = a2 and b1 ? b2.

Types of functions:(examples of functions)


1. Onto function

2. One-to-one function:

3. Identity function:

4. Constant function

5. Linear function:

6. Trigonometrical functions:


Explanation of Types of functions: examples of functions


1. Onto function

If the range of a function is equal to the co-domain then the function is

called an onto function. Otherwise it is called an into function.


Definition: A function f is onto if to each element b in the co-domain, there is

at least one element a in the domain such that b = f(a)

Example for Onto function


2. One-to-one function:

A function is said to be one-to-one if each element of the range is

associated with exactly one element of the domain.

i.e. two different elements in the domain (A) have different images in the

co-domain (B).



Note: (1) A function is said to be injective if it is one-to-one.

(2) It is said to be injective if it is both one-to-one and onto.

Example for one to one function:


3. Identity function:

A function f from a set A to the same set A is said to be an identity

function if f(x) = x for all x e A i.e. f : A ? A is defined by f(x) = x for all

x e A. Identity function is denoted by IA or simply I. Therefore I(x) = x always.

Example of Identity function:

f(x) = x

Understanding Absolute Value Piecewise Functions is always challenging for me but thanks to all math help websites to help me out.

4. Constant function:

If the range of a function is a singleton set then the function is called a

constant function.

Example for constant function:

If

f(x) = 8

then

f (13) = 8

Here f is called the constant function. Whatever comes in to f, the number 8 comes out.


5. Linear function:

If a function f : R ? R is defined in the form f(x) = ax + b then the function

is called a linear function. Here a and b are constants.


6. Trigonometrical functions:

In Trigonometry, we have two types of functions.

(1) Circular functions (2)Hyperbolic functions.

We will discuss circular functions only. The circular functions are

Examples of trigonometrical functions are:

(a) f(x) = sinx (b) f(x) = cos x (c) f(x) = tan x

(d) f(x) = secx (e) f(x) = cosecx (f) f(x) = cotx

Monday, May 11, 2009

A Simple Problem on Finding Integral of a Function

Integral of a Function is very easy to evaluate the value of function. Here is such Integration problem with multi choice answers.

Topic : Integral of a Function
TutorVista helps you to get more multi choice questions and answers and practice the problems.

Problem : The function y(x) satisfying












Choice b is incorrect because of not adding the constant of anti-differentiation to the integral.

Choice c is incorrect because of committing the mistake to write the anti-derivative of 1 / (1 + y2) as cot-1 y.

Choice d is incorrect because of failing to find the integral correctly.

Hope the Integration of given Function is followed and if you have any more queries write to our calculus help and get your problems rectified.