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* M. Shrader-Frechette, Complementary Rational Numbers, Math. Mag., 51 (1978) 90–98. | * M. Shrader-Frechette, Complementary Rational Numbers, Math. Mag., 51 (1978) 90–98. | ||
* E. Midy, De quelques proprietes des nombres et des fractions decimals periodiques, Nantes, (1836), 21 pages. | * E. Midy, De quelques proprietes des nombres et des fractions decimals periodiques, Nantes, (1836), 21 pages. | ||
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== 노트 == | == 노트 == | ||
===말뭉치=== | ===말뭉치=== | ||
| + | # In 1836, E. Midy proved that if p is a prime greater than 5, and the period of 1/p is 2 1.<ref name="ref_472101d4">[http://math.colgate.edu/~integers/h3/h3.pdf Integers: electronic journal of combinatorial number theory 7 (2007), #a03]</ref> | ||
| + | # (The results of Midy and Ginsberg follow quickly from this).<ref name="ref_472101d4" /> | ||
| + | # E. Midy, De quelques proprietes des nombres et des fractions decimals periodiques, Nantes, (1836), 6.<ref name="ref_472101d4" /> | ||
| + | # This theorem, which we will examine in this paper, be- came known as Midys Theorem due to a pamphlet published by E. Midy in Nantes, France, 1836.<ref name="ref_07047442">[http://sand.truman.edu/~dgarth/klinecapstone.pdf A graphical analysis of midy’s theorem]</ref> | ||
| + | # In 1836 E. Midy published at Nantes, France, a pamphlet of twenty-one pages on some topics in number theory with applications to decimals.<ref name="ref_758326cf">[http://emis.impa.br/EMIS/journals/INTEGERS/papers/h2/h2.pdf Integers: electronic journal of combinatorial number theory 7 (2007), #a02]</ref> | ||
| + | # Note that (iii) explains the dierence between 1/77 where k = 3 and gcd(77, 103 which has the Midy property (1), and 1/803 where k = 4 and gcd(803, 104 which (1) fails.<ref name="ref_758326cf" /> | ||
| + | # Midy himself considered the case of period length 3k, but he focused on the sums ai + ai+k + ai+2k, 1 k, which do not give smooth results.<ref name="ref_758326cf" /> | ||
| + | # Section 2 contains the main results as we study the Midy property in a more general setting.<ref name="ref_758326cf" /> | ||
| + | # This is known as Midy’s theorem.<ref name="ref_1d2f78ea">[https://www.johndcook.com/blog/2018/11/19/midys-theorem/ Midy's theorem: fractions with prime denominator]</ref> | ||
# If k is any divisor of the period of the decimal expansion of a/p (where p is again a prime), then Midy's theorem can be generalised as follows.<ref name="ref_5a20be13">[https://en.wikipedia.org/wiki/Midy%27s_theorem Midy's theorem]</ref> | # If k is any divisor of the period of the decimal expansion of a/p (where p is again a prime), then Midy's theorem can be generalised as follows.<ref name="ref_5a20be13">[https://en.wikipedia.org/wiki/Midy%27s_theorem Midy's theorem]</ref> | ||
# To prove the original Midy's theorem, take the special case where h = 2.<ref name="ref_12344c07">[https://handwiki.org/wiki/Midy%27s_theorem Midy's theorem]</ref> | # To prove the original Midy's theorem, take the special case where h = 2.<ref name="ref_12344c07">[https://handwiki.org/wiki/Midy%27s_theorem Midy's theorem]</ref> | ||
| − | # | + | # Now this is even in number therefore 1+8 = 9 which again shows the validity of Midy’s theorem.<ref name="ref_84efc06e">[https://www.geeksforgeeks.org/midys-theorem/ Midy's theorem]</ref> |
| + | # Given numerator and denominator, the task is to find if the resultant floating point number follows Midy’s theorem or not.<ref name="ref_84efc06e" /> | ||
| + | # Write( "Midy's theorem holds!" ); } else { Console.<ref name="ref_84efc06e" /> | ||
# This is to provide the necessary machinery for the proof of Midy's theorem, as well as for completeness.<ref name="ref_b7c9355f">[https://digitalcommons.unl.edu/mathfacpub/48/ A THEOREM ON REPEATING DECIMALS]</ref> | # This is to provide the necessary machinery for the proof of Midy's theorem, as well as for completeness.<ref name="ref_b7c9355f">[https://digitalcommons.unl.edu/mathfacpub/48/ A THEOREM ON REPEATING DECIMALS]</ref> | ||
| − | # | + | # In Extended Midy’s Theorem, the repeating portion is divided into m digits, then their sum is a multiple of 10m - 1.<ref name="ref_cedb9ba6">[https://www.tutorialspoint.com/extended-midy-s-theorem-in-cplusplus Extended Midy's theorem in C++]</ref> |
| − | # Write( "Denominator is not prime, " + "thus Extended Midy's theorem " + "is not applicable" ); return ; } int l = str.<ref name=" | + | # 2352 9411 7647 Extended Midy's theorem holds!<ref name="ref_cedb9ba6" /> |
| + | # We then use our method to give an elementary proof of Midy’s theorem on repeating decimals.<ref name="ref_35609a5a">[https://www.semanticscholar.org/paper/A-SIMPLE-PROOF-OF-MIDY%27S-THEOREM-Hamarsheh-Jaradat/edbcb21bb9dd4e861e5512f819a0702c14c51791 [PDF] A SIMPLE PROOF OF MIDY'S THEOREM]</ref> | ||
| + | # In Extended Midy’s theorem if we divide the repeating portion of a/p into m digits, then their sum is a multiple of 10m -1.<ref name="ref_c9954aeb">[https://www.geeksforgeeks.org/extended-midys-theorem/ Extended Midy's theorem]</ref> | ||
| + | # Write( "Denominator is not prime, " + "thus Extended Midy's theorem " + "is not applicable" ); return ; } int l = str.<ref name="ref_c9954aeb" /> | ||
| + | # Write( "Extended Midy's " + "theorem holds!" ); else Console.<ref name="ref_c9954aeb" /> | ||
| + | # Write( "Extended Midy's " + "theorem doesn't hold!" ); } else if (l % 2 != 0) { Console.<ref name="ref_c9954aeb" /> | ||
| + | # The 2-block property for primes is known as Midy’s theorem (1836).<ref name="ref_8162793e">[https://www.jstor.org/stable/10.4169/002557010x479974 Repeating Decimals: A Period Piece on JSTOR]</ref> | ||
===소스=== | ===소스=== | ||
<references /> | <references /> | ||
| 172번째 줄: | 164번째 줄: | ||
* ID : [https://www.wikidata.org/wiki/Q856158 Q856158] | * ID : [https://www.wikidata.org/wiki/Q856158 Q856158] | ||
===Spacy 패턴 목록=== | ===Spacy 패턴 목록=== | ||
| − | * [{' | + | * [{'LOWER': 'midy'}] |
* [{'LOWER': 'midy'}, {'LOWER': "'s"}, {'LEMMA': 'theorem'}] | * [{'LOWER': 'midy'}, {'LOWER': "'s"}, {'LEMMA': 'theorem'}] | ||
2021년 2월 22일 (월) 23:25 기준 최신판
개요
- '142857의 신비'에서처럼 142857과 같은 수를 적당한 자리마다 쪼개어 더했을때 9가 많이 나타나는 현상에 대한 일반적인 이해
- 1+8=4+5=2+7=9
- 142 + 857=999
- 428 + 571=999
- 285 + 714=999
- 857 + 142=999
- 571 + 248=999
- 712 + 485=999
- 14+28+57=99
- 42+85+71=198=2*99
- 여기서 142857과 같은 수란 cyclic numbers 를 의미한다
- 대부분의 성질은 순환군 을 통하여 이해할 수 있다
- 더 구체적으로는 \(\mathbb{Z}_p^{x}\)에서 10^k 꼴의 원소로 생성되는 부분군과 그 coset 의 원소들의 합을 구하는 문제로 이해할 수 있다
순환마디의 길이가 2의 배수일때
- 정리
소수 p에 대하여, 분수 a/p (\(1\leq a \leq p-1\)) 를 십진법 전개할 때 얻어지는 순환마디의 길이가 2n 이고, 순환마디가 \(a_1a_2\cdots a_{n} a_{n+1}a_{n+2}\cdots a_{2n}\) 라 하자. 다음이 성립한다 \[1\leq i \leq n\] 에 대하여, \(a_{i} + a_{i+n}=9\) 또한 \(a_1a_2\cdots a_{n} + a_{n+1}a_{n+2}\cdots a_{2n} = 99\cdots 99\)(n개의 9) 가 성립한다.
- 증명
분수 a/p (\(1\leq a \leq p-1\)) 를 생각하자.
\(g_k \equiv a10^k \pmod p\) 를 만족시키는 \(1\leq g_k \leq p-1\), \((k=0,1,\cdots,2n-1)\)를 정의하자. \(g_0=a\) 이다.
분수 a/p의 순환마디의 길이가 2n이면, \(10^n \equiv -1 \pmod p\) 가 성립하므로, \(g_n=p-a\) 임을 안다.
\(a_1a_2\cdots a_{n} + a_{n+1}a_{n+2}\cdots a_{2n}=\frac{g_0 10^n-g_n}{p} + \frac{g_{n} 10^n-g_0}{p}=\frac{(g_0+g_n)(10^n-1)}{p}=10^n-1\) ■
예 : 1176470588235294
- p=17
- 2/17 = 0.11764705882352941176470588235294...
- 11764705 + 88235294 = 99999999
- 이 경우엔 위의 증명에서 \(g_k\) 로 쓰인 수는 2, 3, 13, 11, 8, 12, 1, 10, 15, 14, 4, 6, 9, 5, 16, 7 로 주어진다
순환마디의 길이가 3의 배수일 때
- 정리
소수 p에 대하여, 분수 1/p 를 십진법 전개할 때 얻어지는 순환마디의 길이가 3n 이고, 순환마디가 \(a_1a_2\cdots a_{n} a_{n+1}a_{n+2}\cdots a_{2n}a_{2n+1}a_{2n+2}\cdots a_{3n}\) 라 하자. 다음이 성립한다. \[a_1a_2\cdots a_{n} + a_{n+1}a_{n+2}\cdots a_{2n} +a_{2n+1}a_{2n+2}\cdots a_{3n}= 99\cdots 99\]
- 증명
순환마디의 길이가 3n인 분수 1/p 를 생각하자.
\(g_k \equiv 10^k \pmod p\), \(0\leq g_k \leq p-1\) 라 정의하자. \(g_0=1\) 이다.
\(g_{2n} \equiv g_n^2 \pmod p\), \(g_n^3 \equiv 1 \pmod p\) 이므로, \(g_0+g_n+g_{2n}\equiv 1+g_n+g_n^2=(g_n^3-1)/(g_n-1)\equiv 0 \pmod p\) 이다.
따라서 \(g_0+g_n+g_{2n}=p\) 또는 \(g_0+g_n+g_{2n}=2p\)가 성립한다.
그러나 \(1\leq g_k \leq p-1\) 이므로 \(1+g_n+g_{2n}=2p\)일 수 없다. 따라서 \(g_0+g_n+g_{2n}=p\)
\(a_1a_2\cdots a_{n} + a_{n+1}a_{n+2}\cdots a_{2n} +a_{2n+1}a_{2n+2}\cdots a_{3n}=\frac{g_0 10^n-g_n}{p} + \frac{g_{n} 10^n-g_{2n}}{p}+\frac{g_{2n} 10^n-g_{0}}{p}=\frac{(g_0+g_n+g_{2n})(10^n-1)}{p}=10^n-1\) ■
- 일반적으로 소수 p에 대하여, 분수 1/p 를 십진법 전개할 때 얻어지는 순환마디의 길이가 3n 이라고 하자. 분수 a/p (\(1\leq a \leq p-1\)) 또는 (p-a)/p (\(1\leq a \leq p-1\)) 의 순환소수전개를 생각하자. 둘 중의 하나는 \(a_1a_2\cdots a_{n} + a_{n+1}a_{n+2}\cdots a_{2n} +a_{2n+1}a_{2n+2}\cdots a_{3n}= 99\cdots 99\) 다른 하나는, \(a_1a_2\cdots a_{n} + a_{n+1}a_{n+2}\cdots a_{2n} +a_{2n+1}a_{2n+2}\cdots a_{3n}=2* 99\cdots 99\) 를 만족한다
예 : 052631578947368421
- p=19
- 1/19=0.052631578947368421052...
- 52631+578947+368421=999999
- p=7
- 3/7 = 0.4285714286...
- 42+ 85+71=198
- 4/7 = 0.5714285714
- 57+14+28=99
역사
관련된 항목들
매스매티카 파일 및 계산 리소스
사전 형태의 자료
리뷰, 에세이, 강의노트
- A Curious String of Nines
- Hans Liebeck,
- The Mathematical Gazette, Vol. 85, No. 504 (Nov., 2001), pp. 431-438
관련논문
- Lewittes, Joseph. 2006. “Midy’s Theorem for Periodic Decimals”. math/0605182 (5월 7). http://arxiv.org/abs/math/0605182
- A. Gupta and B. Sury, Decimal expansion of 1/p and subgroup sums, Integers: Electronic Journal Of Combinatorial Number Theory 5 (2005),
- Brian D. Ginsberg Midy's (Nearly) Secret Theorem: An Extension after 165 Years, The College Mathematics Journal, Vol. 35, No. 1 (Jan., 2004), pp. 26-30
- M. Shrader-Frechette, Complementary Rational Numbers, Math. Mag., 51 (1978) 90–98.
- E. Midy, De quelques proprietes des nombres et des fractions decimals periodiques, Nantes, (1836), 21 pages.
노트
말뭉치
- In 1836, E. Midy proved that if p is a prime greater than 5, and the period of 1/p is 2 1.[1]
- (The results of Midy and Ginsberg follow quickly from this).[1]
- E. Midy, De quelques proprietes des nombres et des fractions decimals periodiques, Nantes, (1836), 6.[1]
- This theorem, which we will examine in this paper, be- came known as Midys Theorem due to a pamphlet published by E. Midy in Nantes, France, 1836.[2]
- In 1836 E. Midy published at Nantes, France, a pamphlet of twenty-one pages on some topics in number theory with applications to decimals.[3]
- Note that (iii) explains the dierence between 1/77 where k = 3 and gcd(77, 103 which has the Midy property (1), and 1/803 where k = 4 and gcd(803, 104 which (1) fails.[3]
- Midy himself considered the case of period length 3k, but he focused on the sums ai + ai+k + ai+2k, 1 k, which do not give smooth results.[3]
- Section 2 contains the main results as we study the Midy property in a more general setting.[3]
- This is known as Midy’s theorem.[4]
- If k is any divisor of the period of the decimal expansion of a/p (where p is again a prime), then Midy's theorem can be generalised as follows.[5]
- To prove the original Midy's theorem, take the special case where h = 2.[6]
- Now this is even in number therefore 1+8 = 9 which again shows the validity of Midy’s theorem.[7]
- Given numerator and denominator, the task is to find if the resultant floating point number follows Midy’s theorem or not.[7]
- Write( "Midy's theorem holds!" ); } else { Console.[7]
- This is to provide the necessary machinery for the proof of Midy's theorem, as well as for completeness.[8]
- In Extended Midy’s Theorem, the repeating portion is divided into m digits, then their sum is a multiple of 10m - 1.[9]
- 2352 9411 7647 Extended Midy's theorem holds![9]
- We then use our method to give an elementary proof of Midy’s theorem on repeating decimals.[10]
- In Extended Midy’s theorem if we divide the repeating portion of a/p into m digits, then their sum is a multiple of 10m -1.[11]
- Write( "Denominator is not prime, " + "thus Extended Midy's theorem " + "is not applicable" ); return ; } int l = str.[11]
- Write( "Extended Midy's " + "theorem holds!" ); else Console.[11]
- Write( "Extended Midy's " + "theorem doesn't hold!" ); } else if (l % 2 != 0) { Console.[11]
- The 2-block property for primes is known as Midy’s theorem (1836).[12]
소스
- ↑ 1.0 1.1 1.2 Integers: electronic journal of combinatorial number theory 7 (2007), #a03
- ↑ A graphical analysis of midy’s theorem
- ↑ 3.0 3.1 3.2 3.3 Integers: electronic journal of combinatorial number theory 7 (2007), #a02
- ↑ Midy's theorem: fractions with prime denominator
- ↑ Midy's theorem
- ↑ Midy's theorem
- ↑ 7.0 7.1 7.2 Midy's theorem
- ↑ A THEOREM ON REPEATING DECIMALS
- ↑ 9.0 9.1 Extended Midy's theorem in C++
- ↑ [PDF A SIMPLE PROOF OF MIDY'S THEOREM]
- ↑ 11.0 11.1 11.2 11.3 Extended Midy's theorem
- ↑ Repeating Decimals: A Period Piece on JSTOR
메타데이터
위키데이터
- ID : Q856158
Spacy 패턴 목록
- [{'LOWER': 'midy'}]
- [{'LOWER': 'midy'}, {'LOWER': "'s"}, {'LEMMA': 'theorem'}]