NUMBER SYSTEM

 In number system there are various numbers.

• Natural Numbers
• Whole Numbers
• Integers
• Rational Numbers
• Irrational Numbers 
• Real Numbers
• Complex Numbers
• Even Numbers
• Odd Numbers
• Prime Numbers
• Composite Numbers

Now we will discuss the definitions of above one by one

      1.Natural Numbers: 

Natural numbers start from 1. It is denoted by N. 

          N = {1,2,3,...}

     2. Whole Numbers:  

Whole numbers starts from 0. It is denoted by W.

          W = {0,1,2,3,...}

      3. Integers: 

It is denoted by Z. It is the collection of positive and negative numbers with zero. 

          Z = {...,-3,-2,-1,0,1,2,3,...}

      4. Rational Numbers: 

The numbers that can be written in the form of p/q, where p,q are integers and q is non zero.   

   It is denoted by Q.

        

        5. Irrational Numbers: 

The numbers that can not be written in the form p/q. It is denoted by Q'.

         6. Real Numbers: 

 The union of rational and irrational numbers is called real numbers. It is denoted by R.

  

          7. Complex Numbers: 

The number having imaginary part and can be written in the form of "a+ib", where a and b are real numbers and i(iota) is the imaginary number. It can be represented by C. In a+ib, a is real part and ib is imaginary part. 

 

          8.Even Numbers:

The numbers multiples of 2 are even numbers. It is represented by E. 

              E = {0,2,4,6,8,...}

 

           9. Odd Numbers: 

The numbers that are the multiples of 2 are odd numbers. It is represented by O.

              O = {1,3,5,7,...}

 

          10.Prime Numbers 

The number which has only two factors 1 and itself. It is represented by P.

                P= {2,3,5,7,11,...}

2 is the only even prime number.

          

          11. Composite Numbers: 

The numbers other than prime numbers are composite numbers. It is represented by  C. These numbers have more than two factors.

      C = {1,4,6,8,9,...}