The two is a natural number, written in the Indian Arabic system as 2, in Roman numerals as II, in some cases written ii.
Summary
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- 1 Arithmetic properties
- 2 In various numbering bases and others
- 3 Algebraic properties
- 4 Geometric properties
- 5 The two in human anatomy
- 6 Bibliographic citations
- 7 Sources
Arithmetic properties
- It is a natural number, according to Peano’s axiomatic, [1]is the successor of 1; id. est s (1) = 1
- It is an even number; since 2 × 1 = 2
- Well, it is a prime natural number, since there is no divisor of it, between 2 and 1
- It is an additive positive, opposite or inverse integer of -2; their integer divisors are ± 1 and ± 2
- It is a rational number whose multiplying inverse is 1/2; 2 is the representative element of the class of integers {(2; 1); (2h; h)}
- It is a real limit number of 1,999 …
- It is a real complex number
- It is a non-prime Gaussian integer, since it supports factorization (1-i) (1 + 1)
In various numbering bases and others
- In the ternary, quaternary, quinary, senary, octal, decimal, duodecimal, hexadecimal, etc. numbering systems, it is simply denoted by 2.
- Binary 10
- Roman numerals II
- Maya numbering ºº
- Secondordinal
- partitive half
- double: twice as large
- pair: set of two objects; for example, a pair of shoes from the same person.
- ordered pair: arrangement of two elements, subject to their ordering.
Algebraic properties
Nonrational equations and operations
- It is square root of 4, cube root of 8, fourth root of 16, nthroot of 2 n , here n is a positive integer n ≥ 2.
- 2 is the vulgar logarithm of 100
- 2 4= 4 2 , result regardless of the commutativity.
- In a quadratic or quadratic algebraic equation the greatest exponent is 2.
- A quadratic equation has 2 roots.
- An imaginary complex number (a + bi, b ≠ 0) has two square roots.
- is the third Fibonaci number, results by adding x 0= 1 and x 1 = 1. [2]
Abeliano group
- The set {0,1} of division remains in Z, by 2, form an abelian group with the sum:
1 + 1 = 0
1 + 0 = 1
0 + 1 = 1
0 + 0 = 0
neutral element 0
Opposite elements: 1 is 1, 0, 0.
Geometric properties
- Any quadrilateral has exactly two diagonals.
- Two different parallels are cut at exactly two points by a third.
- A point on a line determines two rays only, also only two rays.
- Two intersecting lines determine a plane and only one [3]
- Every line segment has two ends.
- any ceviana that starts from a vertex of a triangle splits the opposite side in parts, if it goes through the inside of the side.
- the trivial topology contains only 2 sets: the set X and the empty set {} [4]
The two in human anatomy
- There are two legs
- there are two feet
- there are two knees
- There are two hands
- there are two eyes
- There are two lungs
- There are two nostrils
- There are two two ears
- there are two shoulders
- There are two feet
- There are kidneys
- There are two elbows
- there are two dolls
- there are two shoulders
- there are two eyebrows
- there are two cheekbones
- there are two cheeks.
All this is a sample of the axial symmetry of many human organs.