Know Your Numbers 9th | 10th | 11th | 12th

1.    Natural numbers N = {1, 2, 3, 4...........+∞} 

2.    Integers Z = {-∞........,-3, -2, -1, 0, 1, 2, 3, 4..........+∞}

3.    Positive integers Z⁺ = {1, 2, 3, 4, ..........+∞}

4.    Negative integers Z^- = {-∞,..........-3, -2, -1}

5.    Non - negative integers or Whole numbers = {0, 1, 2, 3, 4, ..........+∞}

6.    Non - positive integers ={-∞,..........-3, -2, -1,0}

7.    Rational numbers Q = all numbers of the form p/q, where p an q are integers and b ≠ 0 are called rational numbers and their set is denoted by Q.

Q=p/q such that a, b ε Z and b≠0 and HCF of a,b is 1.

·         Every integer is a rational number as it could be written as Q=p/q

·         All recurring decimals are rational numbers e.g. Q= 1/3= 0.333333.

8.    Irrational numbers Q^c = those values which neither terminate nor could be expressed as recurring decimals are called irrational numbers i.e. it cannot be expressed as p/q form, and are denoted by Q^c e.g. sqrt (2) = 1.41421356237309.... , 1+ sqrt (2), 3.14159253.....

9.    Real numbers R = the set which contains both rational and irrational are called real numbers and is denoted by R

R={ ,..............-2, -1, 0, 1, 2, 3, ......13/5, .....16/3.......+ }