Difference between revisions of "Real number"

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A '''real number''' is a number that falls on the real number line. It can have any value. Some examples of real numbers are:<math>1, 2, -23.25, 0, \frac{\pi}{\phi}</math>, and so on. Numbers that are not real are  <math>\ 3i</math>, <math>\ 3+2.5i</math>, <math>\ 3+2i+2j+k</math>, i.e. [[complex number]]s, and [[quaternion]]s.
 
A '''real number''' is a number that falls on the real number line. It can have any value. Some examples of real numbers are:<math>1, 2, -23.25, 0, \frac{\pi}{\phi}</math>, and so on. Numbers that are not real are  <math>\ 3i</math>, <math>\ 3+2.5i</math>, <math>\ 3+2i+2j+k</math>, i.e. [[complex number]]s, and [[quaternion]]s.
  
The set of real numbers is denoted by <math>\mathbb{R}</math>. Commonly used subsets of the real numbers are the [[rational number]]s (<math>\mathbb{Q}</math>), [[integer]]s (<math>\displaystyle\mathbb{Z}</math>), [[natural number]]s (<math>\mathbb{N}</math>) and [[irrational number]]s (sometimes, but not universally, denoted <math>\mathbb{J}</math>).  The real numbers can also be divided between the [[algebraic number]]s and [[transcendental number]]s, although these two classes  are best understood as subsets of the [[complex number]]s.
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The set of real numbers, denoted by <math>\mathbb{R}</math>, is a subset of [[complex number]]s(<math>\mathbb{C}</math>). Commonly used subsets of the real numbers are the [[rational number]]s (<math>\mathbb{Q}</math>), [[integer]]s (<math>\displaystyle\mathbb{Z}</math>), [[natural number]]s (<math>\mathbb{N}</math>) and [[irrational number]]s (sometimes, but not universally, denoted <math>\mathbb{J}</math>).  The real numbers can also be divided between the [[algebraic number]]s and [[transcendental number]]s, although these two classes  are best understood as subsets of the [[complex number]]s.
  
  

Revision as of 20:44, 4 November 2006

A real number is a number that falls on the real number line. It can have any value. Some examples of real numbers are:$1, 2, -23.25, 0, \frac{\pi}{\phi}$, and so on. Numbers that are not real are $\ 3i$, $\ 3+2.5i$, $\ 3+2i+2j+k$, i.e. complex numbers, and quaternions.

The set of real numbers, denoted by $\mathbb{R}$, is a subset of complex numbers($\mathbb{C}$). Commonly used subsets of the real numbers are the rational numbers ($\mathbb{Q}$), integers ($\displaystyle\mathbb{Z}$), natural numbers ($\mathbb{N}$) and irrational numbers (sometimes, but not universally, denoted $\mathbb{J}$). The real numbers can also be divided between the algebraic numbers and transcendental numbers, although these two classes are best understood as subsets of the complex numbers.


See Also

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