翻訳と辞書
Words near each other
・ Hermund Nygård
・ Hermunduri
・ Hermus
・ Hermite constant
・ Hermite distribution
・ Hermite interpolation
・ Hermite Islands
・ Hermite normal form
・ Hermite number
・ Hermite polynomials
・ Hermite reciprocity
・ Hermite ring
・ Hermite spline
・ Hermite's cotangent identity
・ Hermite's identity
Hermite's problem
・ Hermite–Hadamard inequality
・ Hermite–Minkowski theorem
・ Hermitian adjoint
・ Hermitian connection
・ Hermitian function
・ Hermitian hat wavelet
・ Hermitian manifold
・ Hermitian matrix
・ Hermitian symmetric space
・ Hermitian variety
・ Hermitian wavelet
・ Hermits of Saint William
・ Hermits of St. John the Baptist
・ Hermits of the Most Blessed Virgin Mary of Mount Carmel


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Hermite's problem : ウィキペディア英語版
Hermite's problem
Hermite's problem is an open problem in mathematics posed by Charles Hermite in 1848. He asked for a way of expressing real numbers as sequences of natural numbers, such that the sequence is eventually periodic precisely when the original number is a cubic irrational.
==Motivation==

A standard way of writing real numbers is by their decimal representation, such as:
:x=a_0.a_1a_2a_3\ldots\
where ''a''0 is an integer, the integer part of ''x'', and ''a''1, ''a''2, ''a''3… are integers between 0 and 9. Given this representation the number ''x'' is equal to
:x=\sum_^\infty \frac.
The real number ''x'' is a rational number only if its decimal expansion is eventually periodic, that is if there are natural numbers ''N'' and ''p'' such that for every ''n'' ≥ ''N'' it is the case that ''a''''n''+''p'' = ''a''''n''.
Another way of expressing numbers is to write them as continued fractions, as in:
:x=(),\
where ''a''0 is an integer and ''a''1, ''a''2, ''a''3… are natural numbers. From this representation we can recover ''x'' since
:x=a_0 + \cfrac}}.
If ''x'' is a rational number then the sequence (''a''''n'') terminates after finitely many terms. On the other hand, Euler proved that irrational numbers require an infinite sequence to express them as continued fractions.〔(【引用サイトリンク】url=http://math.dartmouth.edu/~euler/pages/E101.html )〕 Moreover, this sequence is eventually periodic (again, so that there are natural numbers ''N'' and ''p'' such that for every ''n'' ≥ ''N'' we have ''a''''n''+''p'' = ''a''''n''), if and only if ''x'' is a quadratic irrational.

抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「Hermite's problem」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.