real numbers

Real Numbers

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What are Real Numbers?

Real numbers are all the numbers that can be represented on the number line. Real numbers are the set of all rational and irrational numbers. The symbol used for Real Numbers is R

Real numbers are used in mathematics, science, engineering, and everyday calculations.

Classification of Real Numbers

Given below is the classification of real numbers

real numbers classification

Properties of Real Numbers

Properties of Real Numbers include Closure Property, Commutative Property, Associative Property, Distributive Property, Identity, Inverse property

Closure Property

If a and b are real numbers:

a + b is real
a − b is real
a × b is real
a ÷ b is real (if b ≠ 0)

Commutative Property

a + b = b + a
a × b = b × a

Example:

3 + 5 = 5 + 3
4 × 2 = 2 × 4

Associative Property

(a + b) + c = a + (b + c)

(a × b) × c = a × (b × c)

Distributive Property

a × (b + c) = ab + ac

Example:

3(4 + 5) = 3×4 + 3×5
= 12 + 15
= 27

Identity Elements

Additive identity:

a + 0 = a

Multiplicative identity:

a × 1 = a

Inverse Property

Additive inverse:

a + (-a) = 0

Multiplicative inverse:

a × 1/a = 1

Decimal Representation of Real Numbers

Types of decimals:

  1. Terminating decimal
1/2 = 0.5
3/4 = 0.75
  1. Non-terminating repeating decimal
1/3 = 0.333...
2/11 = 0.181818...
  1. Non-terminating non-repeating decimal (irrational)
√2 = 1.414213...
π = 3.141592...