{"id":7674,"date":"2021-11-20T14:16:44","date_gmt":"2021-11-20T07:16:44","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=7674"},"modified":"2021-11-20T17:13:31","modified_gmt":"2021-11-20T10:13:31","slug":"the-nao-la-bai-toan-nu-sinh-cachoman","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/the-nao-la-bai-toan-nu-sinh-cachoman\/","title":{"rendered":"Th\u1ebf n\u00e0o l\u00e0 b\u00e0i to\u00e1n “N\u1eef sinh Cach\u01a1man”?"},"content":{"rendered":"\n

N\u0103m 1850, Cach\u01a1man ng\u01b0\u1eddi Anh \u0111\u00e3 \u0111\u01b0a ra m\u1ed9t b\u00e0i to\u00e1n kh\u00e1 l\u00ed th\u00fa: M\u1ed9t b\u00e0 x\u01a1 d\u1eabn 15 n\u1eef sinh h\u00e0ng ng\u00e0y x\u1ebfp h\u00e0ng d\u1ea1o ch\u01a1i.<\/p>\n\n\n\n

B\u00e0 chia c\u00e1c h\u1ecdc sinh<\/a> l\u00e0m n\u0103m t\u1ed5, m\u1ed7i t\u1ed5 c\u00f3 ba n\u1eef sinh theo b\u00e0 \u0111i d\u1ea1o. B\u00e0 kh\u00f4ng mu\u1ed1n ng\u00e0y n\u00e0o c\u0169ng \u0111i d\u1ea1o v\u1edbi c\u00f9ng m\u1ed9t nh\u00f3m ba n\u1eef sinh c\u1ed1 \u0111\u1ecbnh m\u00e0 m\u1ed7i ng\u00e0y v\u1edbi m\u1ed9t t\u1ed5 \u0111\u1ec3 cho m\u1ed7i n\u1eef sinh trong su\u1ed1t m\u1ed7i tu\u1ea7n l\u1ec5 \u0111\u1ec1u c\u00f3 c\u01a1 h\u1ed9i ti\u1ebfp x\u00fac v\u1edbi b\u00e0. \u0110\u00f3 ch\u00ednh l\u00e0 b\u00e0i to\u00e1n \u201cc\u00e1c n\u1eef sinh cach\u01a1man\u201d.<\/p>\n\n\n\n

V\u00e0o n\u0103m sau, Cach\u01a1man \u0111\u00e3 c\u00f4ng b\u1ed1 tr\u00ean t\u1ea1p ch\u00ed \u0111\u00e1p \u00e1n c\u1ee7a \u00f4ng v\u1ec1 b\u00e0i to\u00e1n. Tr\u01b0\u1edbc h\u1ebft \u00f4ng \u0111\u00e1nh s\u1ed1 c\u00e1c n\u1eef sinh t\u1eeb 1 \u0111\u1ebfn 15, c\u00e1ch s\u1eafp x\u1ebfp c\u00e1c \u0111\u1ed9i trong m\u1ed9t tu\u1ea7n s\u1ebd nh\u01b0 sau:<\/p>\n\n\n\n

Th\u1ebf nh\u01b0ng v\u1edbi c\u00e1c nh\u00e0 to\u00e1n h\u1ecdc th\u00ec \u0111\u00e1p \u00e1n n\u00e0y l\u00e0 ch\u01b0a \u0111\u1ee7. H\u1ecd \u0111\u1eb7t ra c\u00e2u h\u1ecfi: li\u1ec7u c\u00f2n c\u00f3 c\u00e1c \u0111\u00e1p \u00e1n n\u00e0o kh\u00e1c n\u1eefa kh\u00f4ng, v\u00e0 li\u1ec7u c\u00f3 c\u00e1ch gi\u1ea3i t\u1ed5ng qu\u00e1t h\u01a1n kh\u00f4ng?<\/p>\n\n\n\n

C\u0169ng n\u0103m \u0111\u00f3, c\u00e1c nh\u00e0 to\u00e1n h\u1ecdc Anh Toenu\u00e2yd\u01a1 (Twelweis) v\u00e0<\/p>\n\n\n\n

Kaix\u00e2y (Kaisei) \u0111\u00e3 th\u00eam m\u1ed9t b\u01b0\u1edbc v\u00e0o b\u00e0i to\u00e1n n\u00e0y.<\/p>\n\n\n\n

Li\u1ec7u c\u00f3 th\u1ec3 v\u1ea1ch ra m\u1ed9t c\u00e1ch s\u1eafp x\u1ebfp trong v\u00f2ng 13 tu\u1ea7n, kh\u00f4ng ch\u1ec9 trong m\u1ed7i tu\u1ea7n ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c quy \u0111\u1ecbnh \u0111\u1eb7t ra cho b\u00e0i to\u00e1n \u1edf tr\u00ean m\u00e0 c\u00f2n ph\u1ea3i l\u00e0m th\u1ebf n\u00e0o cho m\u1ed7i h\u1ecdc sinh<\/a> trong v\u00f2ng 13 tu\u1ea7n l\u1ea1i c\u00f3 th\u1ec3 quay v\u1ec1 \u1edf m\u1ed9t t\u1ed5 c\u00f9ng v\u1edbi c\u00e1c h\u1ecdc sinh<\/a> trong m\u1ed9t ng\u00e0y tr\u01b0\u1edbc \u0111\u00f3 trong chu tr\u00ecnh n\u00e0y.<\/p>\n\n\n\n

B\u00e0i to\u00e1n \u0111\u00e3 h\u1ebft s\u1ee9c kh\u00f3, m\u00e3i \u0111\u1ebfn n\u0103m 1979 m\u1edbi \u0111\u01b0\u1ee3c \u0110ana (Dangars) gi\u1ea3i \u0111\u01b0\u1ee3c nh\u1edd m\u00e1y t\u00ednh \u0111i\u1ec7n t\u1eed.<\/p>\n\n\n\n

Cach\u01a1man ch\u1ec9 \u0111\u1eb7t ra b\u00e0i to\u00e1n v\u1edbi 15 n\u1eef sinh, nh\u01b0ng c\u00e1c nh\u00e0 to\u00e1n h\u1ecdc \u0111\u00e3 m\u1edf r\u1ed9ng \u0111\u1ebfn 3k n\u1eef h\u1ecdc sinh<\/a> v\u00e0 b\u00e0i to\u00e1n n\u1eef sinh \u0111\u00e3 \u0111\u01b0\u1ee3c m\u1edf r\u1ed9ng r\u1ea5t nhi\u1ec1u.<\/p>\n\n\n\n

L\u1eddi gi\u1ea3i t\u1ed5ng qu\u00e1t c\u1ee7a b\u00e0i to\u00e1n \u0111\u01b0\u1ee3c m\u1ed9t sinh vi\u00ean h\u1ec7 to\u00e1n c\u1ee7a tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc s\u01b0 ph\u1ea1m C\u00e1t L\u00e2m (Trung Qu\u1ed1c) l\u00e0 L\u1ee5c Gia Hi \u0111\u01b0a ra n\u0103m 1961. Nh\u01b0ng \u0111\u00e1ng ti\u1ebfc c\u00e1ch gi\u1ea3i v\u1eabn ch\u01b0a \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1.<\/p>\n\n\n\n

N\u0103m 1971, m\u1ed9t h\u1ecdc gi\u1ea3<\/a> Italia l\u00e0 Xcathari (Scathari) v\u00e0 Uynx\u01a1n (Wilson), m\u1ed9t gi\u00e1o s\u01b0 to\u00e1n h\u1ecdc tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc Cacha (Cachar), \u0111\u00e3 c\u00f4ng b\u1ed1 l\u1eddi gi\u1ea3i v\u1ec1 b\u00e0i to\u00e1n Cach\u01a1man v\u00e0 gi\u1ea3i quy\u1ebft tr\u1ecdn v\u1eb9n b\u00e0i to\u00e1n n\u00e0y.<\/p>\n\n\n\n

N\u0103m 1981, L\u1ee5c Gia Hi \u0111\u00e3 tr\u1edf th\u00e0nh m\u1ed9t nh\u00e0 to\u00e1n h\u1ecdc xu\u1ea5t s\u1eafc nh\u01b0ng v\u1eabn \u0111\u1ec3 t\u00e2m nghi\u00ean c\u1ee9u b\u00e0i to\u00e1n n\u1eef sinh Cach\u01a1man. Vi\u1ec7c gi\u1ea3i b\u00e0i to\u00e1n n\u1eef sinh Cach\u01a1man m\u1ed9t c\u00e1ch c\u01a1 b\u1ea3n c\u00f3 li\u00ean quan v\u1edbi m\u1ed9t s\u1ed1 b\u00e0i to\u00e1n ph\u1ee9c t\u1ea1p h\u01a1n l\u00e0 b\u00e0i to\u00e1n nh\u00f3m ba Stanay. B\u00e0i gi\u1ea3i \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1 tr\u00ean m\u1ed9t t\u1eadp s\u00e1ch c\u00f3 uy t\u00edn c\u1ee7a to\u00e1n h\u1ecdc th\u1ebf gi\u1edbi v\u00e0o n\u0103m 1983 \u201cL\u00ed thuy\u1ebft t\u1ed5 h\u1ee3p\u201d.<\/p>\n\n\n\n

Nh\u01b0ng b\u00e0i to\u00e1n nh\u00f3m ba Stanay l\u00fac \u0111\u00f3 c\u00f2n ch\u01b0a \u0111\u01b0\u1ee3c gi\u1ea3i quy\u1ebft tr\u1ecdn v\u1eb9n. B\u00e0i to\u00e1n \u0111\u01b0\u1ee3c nh\u00e0 to\u00e1n h\u1ecdc H\u00e0 Lan l\u00e0 Talin (Thalins) ho\u00e0n th\u00e0nh v\u00e0o th\u00e1ng 10 n\u0103m 1989.<\/p>\n\n\n\n

C\u1ea7n n\u00f3i th\u00eam r\u1eb1ng b\u00e0i to\u00e1n n\u1eef sinh Cach\u01a1man kh\u00f4ng c\u00f3 l\u1eddi gi\u1ea3i duy nh\u1ea5t m\u00e0 c\u00f3 th\u1ec3 c\u00f3 nhi\u1ec1u l\u1eddi gi\u1ea3i kh\u00e1c nhau.<\/p>\n\n\n\n

T\u1eeb kho\u00e1: B\u00e0i to\u00e1n n\u1eef sinh Cach\u01a1man.<\/p>\n\n\n\n

<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"

N\u0103m 1850, Cach\u01a1man ng\u01b0\u1eddi Anh \u0111\u00e3 \u0111\u01b0a ra m\u1ed9t b\u00e0i to\u00e1n kh\u00e1 l\u00ed th\u00fa: M\u1ed9t b\u00e0 x\u01a1 d\u1eabn 15 n\u1eef sinh h\u00e0ng ng\u00e0y x\u1ebfp h\u00e0ng d\u1ea1o ch\u01a1i. B\u00e0 chia c\u00e1c h\u1ecdc sinh l\u00e0m n\u0103m t\u1ed5, m\u1ed7i t\u1ed5 c\u00f3 ba n\u1eef sinh theo b\u00e0 \u0111i d\u1ea1o. B\u00e0 kh\u00f4ng mu\u1ed1n ng\u00e0y n\u00e0o c\u0169ng \u0111i d\u1ea1o v\u1edbi c\u00f9ng […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,9],"tags":[],"class_list":["post-7674","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-toan-hoc"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7674","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=7674"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7674\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7674"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7674"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7674"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}