Wednesday, September 12

Set Theory Venn Diagrams

INTRODUCTION TO SET THEORY VENN DIAGRAMS:

Define Set:

A set is a collection of well defined objects and these things which constitute a set are called its ‘elements’ or ‘members’.

Example:Set of odd numbers from 1 to 10 = {1, 3, 5, 7, 9}

Define Set theory - Venn diagram:

The geometrical representation of different types of sets is called “Venn diagram”

Example:

Basic Operations on Sets:

The primary operation on a set is,

- Union of sets:

The union of two nonempty sets A and B is the set consisting of all elements belonging to A or B or to both of them.

Ex: A = {1, 2, 5, 6} and B= {3, 7, 8, 9}

A `uu` B= {1, 2, 3, 5, 6, 7, 8, 9}

- Intersection of sets:

Let P and Q are two sets. The set of elements present in both the sets A and B are known as the set intersection of P and Q.

Ex P = {1, 2, 4, 6, 8}, Q = {6, 8, 9, 10, 12}.

P  `nn` Q = {6, 8}.

Algebra is widely used in day to day activities watch out for my forthcoming posts on algebra word problem solver online free and math problem solver algebra 2. I am sure they will be helpful.

Set Theorey Notations Used in Venn Diagrams

Let A, B are two sets and the following are the notations that are used in Venn diagrams:

AUB – >A union B which means that everything that is in either of the sets

A n B -> A intersect B which means that only the things that are in both of the sets

A c    -> A complement which means that everything in the object that is outside of A

A- B -> A minus B or A complement B which means everything in A except for anything in its overlap with B

- (AUB) -> not (A union B) which means everything outside of A and B

- (AnB) -> not (A intersect B) which means everything outer of the overlap of A and B



Set Theory Venn Diagrams Example Problem:

Mary asked 100 coffee drinkers whether they like cream or sugar in their coffee. 16 drinkers using cream only and 20 using both and 35 drinkers like sugar only.   How many like cream, sugar, cream but not sugar, sugar but not cream, cream and sugar, cream or sugar? Apply set theory Venn diagrams to solve.

Solution:We can find the solution for these questions using set theory Venn diagrams like


We should add 20 + 16 to find the no. of drinkers like cream

And 16+35 gives the number of sugar liking drinkers

Sugar but not cream is 35 and cream but not sugar is 16. Both gives 20 and we should add all 16+35+20 to find how many drinkers like cream or sugar which is 71.

Operations and Laws of Set Theory Venn Diagrams:

Operations on Sets:

Union of Sets
Intersection of sets
Disjoint of sets
Difference of two sets
Symmetrical difference of two sets
Complement of  a set
Algebraic laws:

Idempotent Laws
Identity laws
Associative laws
De-Morgan's Laws
Distributive laws

Friday, September 7

Linear Inequalities

Introduction

Two algebraic expressions or two real numbers related by the symbol '<', '>', '<=' or '>=' form an linear inequality.

Examples of numerical inequalities: 3 < 5; 7 > 5 x < 5;

Examples of literal inequalities: y > 2; x <= 3, y >= 4.

3 > x > 5 (read as x is greater than or equal to 3 and less than 5) and 2 < y < 4 are the examples of double inequalities.

How to solve linear inequality:

Added or subtracted by the same number on both side of the inequality.

Multiplied or divided by the same number on both side of the inequality but if we divide or multiply by a negative number, we must reverse the inequality sign.

Worked Examples for Linear Inequalities :

Example 1:

Solve the linear inequality: 5x – 3 < 7

Solution:

5x – 3 < 7

Add 3 on both side of the equation

5x - 3 + 3 < 7 + 3

5x < 10

Divide by 5 on both side of the equation

5x / 5 < 10 / 5

x<2 2="" br="" infinity="" is="" so="" solution="" the="">
Example 2:
Solve the linear inequality: 7x + 3 < 5x + 9

Solution:

7x + 3 < 5x + 9

Subtract 3 to the both side of the equation

7x + 3 - 3 < 5x + 9 -3

7x < 5x + 6

Subtract 5x on both sides of the equation

7x - 5x < 5x + 6 - 5x

2x<6 2="" both="" br="" by="" divide="" equation="" of="" on="" sides="" the="">
2x / 2 < 6 / 2

x < 3

So, the solution is (-infinity, 3).

I am planning to write more post on show me how to multiply fractions, how to solve and graph linear inequalities. Keep checking my blog.

Additional Linear Inequality Examples

Example 3: Solve the linear inequality: 5x – 3 < 3x +1

Solution:

5x – 3 < 3x +1

Add 3 to the both side of the equation

5x – 3+3 < 3x +1+3

5x < 3x + 4

Subtract 3x on both sides of the equation

5x - 3x < 4

2x < 4

Divide by 2 on both side of the equation

2x / 2 < 4 / 2

x<2 2="" br="" inequality="" infinity="" is="" range="" so="" the="">
Example 4: Solve the linear inequality: 37 – (3x + 5) > 9x – 8 (x – 3)

Solution:

37 – (3x + 5) > 9x – 8 (x – 3)

37- 3x - 5 > 9x - 8x + 24

-3x + 32 > 1x + 24

Subtract x on both sides of the equation

-3x+32- x > 1x + 24 - x

-4x +32 > 24

Subtract 32 on both sides of the equation

-4x + 32-32 > 24 - 32

-4x > -8

Divide by -4 on both sides of the equation and change the inequality sign

-4x / -4 < -8 / -4

x < 2 So, the solution is (-infinity, 2)

Tuesday, September 4

Reflex Measure of an Angle

Introduction to reflex measure of an angle.

Let x be the given angle. Then we can define three important angles as follows:

1. The complimentary angle of x is 90 – x

2. The supplementary angle of x is 180 – x.

3. The reflex angle of x is 360 – x.

The above difference of angles must be known clearly.

Example: if x = 400, Then the reflex angle of x is given by 360 – x = 360 - 40 = 3200.

The above diagram, clearly shows that, the reflex angle of any angle is the remaining value of 360 beside the given angle x.

Now let us see some examples to understand and to practice these concepts in the following article.

Example Problems on Reflex Measure of Angle.
Ex 1: What is the reflex angle of  800?

Solution: The reflex angle of 80 is 360 - 80 = 2800.

Ex 2: Find the reflex of A is the given diagram Here XY is a straight line.

Solution: In the given diagram, A+15 = 180.

Therefore A = 180 -15 = 1650.

Therefore the reflex angle is given by 360 - A = 360 – 165 = 1950.

Ex 3: Find the reflex angle of B in the given diagram. Here XY is a straight line. Angle POY is 900.
Solution:

Since POY = 90

POY = 35+B = 90 implies B = 90-35

Therefore B = 550.

Therefore the reflex angle of B is 360 – B = 360 -55

= 3050.

Ex 4: Find the reflex angle of P in the given diagram. Here XY is a straight line.
Solution: Since XY is a straight line, Angle XOY = 180

implies 25+P = 180

implies P =180-25 =1550

Therefore the reflex angle of P is 360 – P = 360 -155 = 2050.



Ex 5: The reflex angle of P is 2250 . Find P.

Solution: Given: The reflex angle of P is 225 implies 360 - P = 225.

implies –P = 225 - 360 = -1350.

Therefore P =1350.

Between, if you have problem on these topics get help with math problems, please browse expert math related websites for more help on college algebra solver step by step.

Practice Problems on Reflex Measure of Angle

1. Find the reflex angle of 300.

[Ans: Reflex angle of 300 is 3300]

2. If the reflex angle of X is 1500, find the angle X.

[Ans: X = 2100]

I hope these examples would have helped you to find and measure the reflex angle for the given angle.

Saturday, September 1

Introduction to Practice Number Line


Introduction :                                                                                           

A number line is a line on which real numbers are placed according to their value. For example, the number 3.5 or 3 1/2 corresponds with the point on a number line that is halfway between the numbers 3 and 4. Each point on a number line corresponds to a real number, and each real number has a unique point on the Number line that corresponds only to that number. Number lines are valuable tools which are easily used to illustrate the mathematical concepts such as subtraction, addition and positive and negative numbers.          

The number line is usually represented as a horizontal line. An arrowhead on either end of the line is suggests that the line  continues indefinitely in the positive and negative real number's which are denoted by ‘R’. The real numbers may be irrational and rational numbers, integers, whole numbers or also natural numbers.      

Steps to Draw a Number Line:

In order to draw a number line,

Draw a straight line with 1 inch divisions.
Position the bottom edge of your ruler at the start of the line. Mark each 1inch measurement divisions on the line until you reach the end of the line. Draw an arrow head (i.e., "<" and ">") on the left and right ends of the line.
Now, draw a perpendicular line at the centre and label it "0” where both the lines meet.
The divisions on the right hand side of the horizontal line will be the positive divisions i.e., numbers are prefixed with “+” sign and written as +1   +2   +3   +4   +5   +6……….

·       The divisions on the left hand side of the horizontal line will be the negative divisions i.e., numbers are prefixed with “-” sign and written as -1   -2   -3   -4    -5   -6………..


The points on a number line are called as the coordinates and the zero point is called the origin and the numbers on the right side of the origin are the positive numbers and those on the left side of the origin are the negative numbers. Hence the number line is divided as two symmetric halves by origin.

My forthcoming post is on factoring polynomials problems, change fractions to decimals will give you more understanding about Algebra.

Examples for Practice Based on Number Line:

Below are the examples on how to perform addition and subtraction using Number line


Ex 1: +6  - +2

Sol: +6 - +2 = +6  - 2 = +4

Ex 2: +8  +  +2

Sol: +8  +  +2 = +10

similarly,

+7 - +10 =    +7 - 10 =    -3
+7 + -10 =    +7 - 10 =    -3
+7+ +10 =    +7 + 10 =    +17
-7 - -10 =    -7 + 10 =    +3

Thursday, August 30

Factor the Trinomial Calculator

Introduction of factor the trinomial calculator :
Any expression which have three non zero terms is known as trinomial.

Ex :

Ax2+ Bx + C  is a trinomial because it is having three non zero terms ( Ax2 , Bx and C)

While cx + d is not a trinomial because it has only two non zero terms ( cx and d ) hence it is known as binomial.

Factor of trinomial- By factoring trinomial we mean that to express the trinomial as a product of two binomials.

Ex : Suppose we have to factorize 35 .Then we have to find two prime numbers whose product is zero so factors of 35 will be 5 and 7 . In the same way we will write each trinomial as a product of two binomials.

Example for Factor the Trinomial Calculator

We have to follow the following steps for factoring type of trinomials

1. Look for the sign of third term.

2. if the sign of third term is positive then we have to divide the coefficient  of middle term in two parts  in such a way that sum of these two part is equal to the middle terms and product of these two parts is equal to the coefficient of third term.

3. Take the common parts out and solve.

Ex : factorize  x2 + 14x + 24

Sol :

Step1. Sign of third term is positive

Step 2. Coefficient of middle term is 14. So we will divide in two parts such that the sum of these two parts is 14 and product of these two parts is 24. Clearly these two parts will be 12 and 2.

Step3.

x2 + 14x + 24

= x2 +  (12 + 2 )x + 24

= x2 +  12x + 2x + 24

= x ( x + 12 ) + 2 ( x +12 )  [take out the common terms and solve]

= (x + 12 ) (x + 2 )

So x2 +  14x + 24 = (x +12 ) (x +2)

I am planning to write more post on list of all prime numbers, translate to an algebraic expression. Keep checking my blog.

Explaination for Factoring the Trinomial of Type X^2 + Bx - C

We have to follow following steps.

1. Look for the sign of third term.

2. If the sign of third term is negative then we have to divide the coefficient  of middle term in two parts  in such a way that difference of these two part is equal to the middle terms and product of these two parts is equal to the coefficient of third term.

3. Take the common parts out and solve.

Example: Factorize  x2 -5x -6

Solution:

Step1. Sign of third term is negative

Step 2. Coefficient of middle term is 5. So we will divide in two parts such that the difference of these two parts is 5 and product of these two parts is 6. Clearly these two parts will be 6 and 1.

Step3.

x2 - 5x – 6

= x2 – 6x  + x – 6

= x ( x -6 ) + 1 (x -6 )

= (x +1 ) (x – 6)

So x2 - 5x – 6 = (x +1 ) (x – 6)

Rules for Factoring the Trinomial of Type Ax^2 + Bx - C and Ax^2 + Bx +c

We have to follow following steps.

1. Look for the sign of third term.

2. Multiply the coefficient of first term and last term,say the product is A

3. If the sign of the last term is positive then divide the A in two parts such that addition of those parts equal to the middle term and multiplication of those two parts equals A.If the sign of the last term is negative then divide the A in two parts such that subs traction of those parts equal to the middle term and multiplication of those two parts equals A.

4. Take out the common factor and solve.

Tuesday, August 28

Sum of Positive Integers

Introduction about sum of positive integers:

The integers are formed by the natural numbers including 0 (0,1,2,3…..) together with the negatives  of the non-zero natural numbers (-1, -2, -3, ...) The positive integers are 0,1,2,3…..

To find the sum of consecutive positive integers we have to use the following formula,

                 `sum_(i=1)^n`n = `(n (n+1))/(2)`  where n is the positive integer

Properties of integer

Addition (or) sum: If we have added two positive integers the result will be a positive integer. If negative integer involved in addition means the result is based on the biggest number.

Commutative property: a+b= b+a
Associative property:a+(b+c)=(a+b)+c
Identity property: a+1= 1+a

Algebra is widely used in day to day activities watch out for my forthcoming posts on how to solve quadratic inequalities and algebra linear equations. I am sure they will be helpful.

Lets Solve some Examples on Sum of Positive Integers

Pro 1 :Find the sum of consecutive positive integers from 1 to 25

Solution:From the formula  `sum_(i=1)^n`n  = `(n (n+1))/(2)`

Here n =25  `sum_(i=1)^25`25  = `(25 *(25+1))/(2)`

                                       = `(25 * 26 )/(2)`

                                       =`(650)/(2)`

                                       = 325

The answer for sum of consecutive integer from 1 to 25 is 325

Pro 2:Find the sum of consecutive positive integers from 1 to 50

Solution:From the formula  `sum_(i=1)^n`n  = `(n (n+1))/(2)`

Here n =50  `sum_(i=1)^50`50  = `(50 *(50+1))/(2)`

                                       = `(50 * 51)/(2)`

                                       =`(2550)/(2)`

                                       = 1275

The answer for sum of consecutive integer from 1 to 25 is 1275

Pro 3:Find the sum of positive integer 5 + 10.

The symbol plus +, represents the positive direction.
So, To find 5+10, number line starts from 5,  go to the  positive direction and move 10 units frontward we will get the 15
5+10=15

The answer is 15

Some more Problems on Sum of Positive Integers

Pro 4: Find the sum of consecutive positive integers from 1 to100

Solution:

From the formula  `sum_(i=1)^n`n  = `(n (n+1))/(2)`

Here n =100 =  `sum_(i=1)^100`100 = `(100 *(100+1))/(2)`

                                       = `(100 * 101)/(2)`

                                       =`(10100)/(2)`

                                       = 5050

The answer for sum of consecutive integer from 1 to 100 is 5050

Pro 5:Find the sum of consecutive positive integers from 1 to 45

Solution:From the formula `sum_(i=1)^n`n  = `(n (n+1))/(2)`

Here n =45  `sum_(i=1)^45`45  = `(45 *(45+1))/(2)`

                                       =`(45 * 46)/(2)`

                                       =`(2070)/(2)`

                                       = 1035

The answer for sum of consecutive integer from 1 to 45 is 1035

Friday, August 24

Introduction of add polynomials

Introduction of add polynomials:

          A polynomial is an expression formed by variables and constant, using the  fundamental operation addition, subtraction, multiplication, and non-negative, number exponents. For example, x 2 - 4x + 5 is a polynomial. An algebraic expression, ax 2 is called a monomial in x, x is a variable a. The number a is called the coefficient of x^2 , the degree of the monomial. The sum of two monomials is called a binomial. The sum of a limited number of monomials in x is called a polynomial in x.

Please express your views of this topic solve a math problem by commenting on blog.

Polynomials and Methods for Adding

The monomials in a polynomial are called the terms and the highest degree of the terms, the degree of the polynomial. The coefficient of the highest power of x in a polynomial is called the leading coefficient of the polynomial. For example, 3x – 1 + 5x^2 + 6x^5 – 4x3 is a polynomial of degree 5 with terms 2x, –1, 5x^2, 6x^5 and –4x3 and most important coefficient 6. The terms of a polynomial are real numbers, they are rearranged using the property of real numbers

A first degree polynomial is called a linear polynomial. A second degree polynomial is called a quadratic polynomial. A degree polynomial is third called as cubic polynomial and a degree polynomial is four called as bi-quadratic polynomial. Since the terms of a polynomial are numbers, all polynomials represent numbers. So we can add, subtract, multiply and divide polynomials. The following method used to add the polynomials.

Adding Polynomials Examples

Ex 1: Find the sum or add of 3x^4 – 4x^2 + 5x + 3 and 4x + 6x3 – 6x^2 – 2 polynomials.

Sol :  Using the properties of real numbers, we add the polynomial

(3x^4 – 4x^2 + 5x + 3) + (6x3 – 6x^2 + 4x – 2) = 3x^4 + 6x3 – 4x^2 – 6x^2 + 5x + 4x + 3 – 2

= 3x^4 + 6x3 – (4+6)x^2 + (5+4)x + 1

= 3x^4 + 6x3 – 10x^2 + 9x + 1.

The following method is useful in add two polynomials

3x^4 + 0x3 – 4x^2 + 5x + 3

0x^4 + 6x3 – 6x^2 + 4x – 2

_____________________

3x^4 + 6x3– 10x^2 + 9x + 1

_____________________