<\/span>Soi c\u1ea7u theo chu k\u1ef3 l\u00e0 g\u00ec?<\/h2>\nSoi c\u1ea7u theo chu k\u1ef3 th\u1ef1c ch\u1ea5t l\u00e0 m\u1ed9t c\u00e1ch d\u1ef1 \u0111o\u00e1n c\u00e1c con s\u1ed1 c\u00f3 x\u00e1c su\u1ea5t n\u1ed5 cao nh\u1ea5t trong m\u1ed9t k\u1ef3 m\u1edf th\u01b0\u1edfng d\u1ef1a v\u00e0o c\u00e1c v\u00f2ng l\u1eb7p c\u1ee7a ch\u00fang.<\/p>\n
C\u00f3 v\u00f4 v\u00e0n c\u00e1c quy lu\u1eadt kh\u00e1c nhau t\u01b0\u01a1ng \u1ee9ng v\u1edbi nh\u1eefng t\u00ednh to\u00e1n kh\u00e1 \u0111a d\u1ea1ng. Ng\u00e0y nay ch\u00fang ta v\u1eabn g\u1ecdi ch\u00fang v\u1edbi m\u1ed9t c\u00e1i t\u00ean chung l\u00e0 b\u1ea1c nh\u1edb hay b\u1ea1c nh\u1edb l\u00f4 \u0111\u1ec1.<\/p>\n
L\u00e0 t\u1ed5ng h\u1ee3p r\u1ea5t nhi\u1ec1u kinh nghi\u1ec7m c\u1ee7a c\u00e1c th\u1ebf h\u1ec7 ng\u01b0\u1eddi ch\u01a1i l\u00f4 \u0111\u1ec1 n\u00ean theo th\u1eddi gian c\u00e1c quy t\u1eafc n\u00e0y \u0111\u01b0\u1ee3c ho\u00e0n thi\u1ec7n h\u01a1n. C\u0169ng v\u00ec tr\u1ea3i qua r\u1ea5t nhi\u1ec1u giai \u0111o\u1ea1n l\u1ecbch s\u1eed h\u00ecnh th\u00e0nh v\u00e0 ph\u00e1t tri\u1ec3n c\u1ee7a x\u1ed5 s\u1ed1 n\u00ean k\u1ebft qu\u1ea3 n\u00e0y \u0111\u00e3 \u0111\u01b0\u1ee3c ki\u1ec3m ch\u1ee9ng \u0111\u1ed9 chu\u1ea9n x\u00e1c.<\/p>\n
\u0110\u1ebfn t\u1eadn th\u1eddi \u0111i\u1ec3m n\u00e0y, c\u00e1ch soi c\u1ea7u theo chu k\u1ef3 v\u1eabn \u0111\u01b0\u1ee3c c\u00f4ng nh\u1eadn l\u00e0 hi\u1ec7u qu\u1ea3 theo n\u0103m th\u00e1ng. \u0110\u1eb7c bi\u1ec7t ch\u00fang ph\u00e1t huy t\u00e1c d\u1ee5ng t\u1ed1t nh\u1ea5t l\u00e0 khi \u00e1p d\u1ee5ng b\u00ed k\u00edp l\u00f4 \u0111\u1ec1 Mi\u1ec1n B\u1eafc<\/strong>.<\/p>\nTheo c\u00e1c chuy\u00ean gia th\u00ec vi\u1ec7c t\u00ednh s\u1ed1 l\u00f4 \u0111\u1ec1 \u0111\u1eb9p d\u1ef1a v\u00e0o c\u00e1c v\u00f2ng l\u1eb7p gi\u00fap ng\u01b0\u1eddi ch\u01a1i ti\u1ebft ki\u1ec7m th\u1eddi gian ph\u00e2n t\u00edch s\u1ed1 li\u1ec7u, t\u00ecm t\u00f2i con s\u1ed1. Ch\u1ec9 c\u1ea7n tra c\u1ee9u c\u00e1c k\u1ebft qu\u1ea3 theo b\u1ea3ng b\u1ea1c nh\u1edb l\u00e0 \u0111\u00e3 t\u00ecm ra \u0111\u01b0\u1ee3c con s\u1ed1 c\u00f3 t\u1ef7 l\u1ec7 n\u1ed5 cao.<\/p>\n
Ph\u1ea3i th\u1eeba nh\u1eadn r\u1eb1ng c\u00e1ch n\u00e0y \u0111\u00f2i h\u1ecfi kh\u00f4ng qu\u00e1 nhi\u1ec1u k\u1ef9 n\u0103ng v\u00ec ph\u1ea7n l\u1edbn c\u00e1c b\u01b0\u1edbc nghi\u00ean c\u1ee9u \u0111\u00e3 \u0111\u01b0\u1ee3c chuy\u00ean gia soi c\u1ea7u l\u00f4 \u0111\u1ec1 nhi\u1ec1u th\u1ebf h\u1ec7 th\u1ef1c hi\u1ec7n. V\u1eady th\u00ec h\u1eadu b\u1ed1i ch\u00fang ta kh\u00f4ng c\u00f3 l\u00fd do g\u00ec \u0111\u1ec3 b\u1ecf ph\u00ed m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p t\u00ednh s\u1ed1 l\u00f4 \u0111\u1ec1 chu\u1ea9n \u0111\u1ebfn nh\u01b0 v\u1eady.<\/p>\nPh\u01b0\u01a1ng ph\u00e1p soi c\u1ea7u theo chu k\u1ef3<\/em><\/strong><\/figcaption><\/figure>\n<\/span>C\u00e1c ph\u01b0\u01a1ng ph\u00e1p soi c\u1ea7u l\u00f4 theo chu k\u1ef3<\/h2>\nTr\u00ean b\u1ea3ng KQXS c\u00f3 r\u1ea5t nhi\u1ec1u v\u1ecb tr\u00ed kh\u00e1c nhau v\u00e0 khi k\u1ebft h\u1ee3p s\u1ebd t\u1ea1o th\u00e0nh nhi\u1ec1u v\u00f2ng l\u1eb7p. Ch\u00fang ta c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng b\u1ea5t c\u1ee9 d\u1eef li\u1ec7u n\u00e0o \u0111\u1ec3 t\u00ecm ti\u1ebfng k\u1ebft cho m\u00ecnh v\u00e0 d\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 g\u1ee3i \u00fd c\u1ee5 th\u1ec3 nh\u1ea5t.<\/p>\n
<\/span>Soi c\u1ea7u l\u00f4 t\u00f4 theo th\u1ee9 trong tu\u1ea7n<\/h3>\nB\u1ea1c nh\u1edb n\u00e0y d\u1ef1a v\u00e0o th\u1ed1ng k\u00ea t\u1ea7n su\u1ea5t n\u1ed5 c\u1ee7a c\u00e1c con s\u1ed1 theo th\u1ee9 trong tu\u1ea7n. \u0110\u1ec3 t\u00ecm ra \u0111\u01b0\u1ee3c c\u00e1c chu k\u1ef3 l\u1eb7p n\u00e0y l\u00e0 c\u1ea3 m\u1ed9t qu\u00e1 tr\u00ecnh d\u00e0i nghi\u00ean c\u1ee9u. K\u1ebft qu\u1ea3 cu\u1ed1i c\u00f9ng l\u00e0 ta c\u00f3 \u0111\u01b0\u1ee3c nh\u1eefng tham kh\u1ea3o chu\u1ea9n x\u00e1c nh\u1ea5t.<\/p>\n
\nTh\u1ee9 Hai<\/strong> l\u00f4 02, 23<\/strong> hay l\u1ed9 di\u1ec7n nh\u1ea5t.<\/li>\nTh\u1ee9 Ba<\/strong> th\u01b0\u1eddng c\u00f3 c\u1eb7p 37, 73<\/strong> xu\u1ea5t hi\u1ec7n.<\/li>\nTh\u1ee9 T\u01b0<\/strong> l\u00e0 ng\u00e0y c\u00f3 t\u1ea7n su\u1ea5t n\u1ed5 66, 64<\/strong> nhi\u1ec1u nh\u1ea5t.<\/li>\nTh\u1ee9 N\u0103m<\/strong> th\u00ec c\u1eb7p 45, 54<\/strong> c\u00f3 chu k\u1ef3 hay ra.<\/li>\nTh\u1ee9 S\u00e1u<\/strong> n\u00ean t\u1eadp trung v\u00e0o l\u00f4 67, 76<\/strong>.<\/li>\nTh\u1ee9 B\u1ea3y<\/strong> c\u00f3 x\u00e1c su\u1ea5t n\u1ed5 l\u00f4 97, 79<\/strong> cao nh\u1ea5t.<\/li>\nCh\u1ee7 Nh\u1eadt<\/strong> l\u00e0 ng\u00e0y l\u00f4 56, 65<\/strong> c\u00f3 t\u1ef7 l\u1ec7 n\u1ed5 l\u1edbn v\u00e0 r\u1ea5t \u0111\u00e1ng xu\u1ed1ng ti\u1ec1n.<\/li>\n<\/ul>\nTr\u00ean \u0111\u00e2y ch\u1ec9 l\u00e0 c\u00e1c con s\u1ed1 c\u00f3 chu k\u1ef3 hay ra nh\u1ea5t. Chu k\u1ef3 n\u00e0y c\u00f3 th\u1ec3 c\u00f3 s\u1ef1 thay \u0111\u1ed5i n\u00ean ng\u01b0\u1eddi ch\u01a1i c\u0169ng c\u1ea7n c\u1eadp nh\u1eadt li\u00ean t\u1ee5c \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o c\u00e1c d\u1ef1 \u0111o\u00e1n chu\u1ea9n x\u00e1c nh\u1ea5t.<\/p>\n
<\/span>Chu k\u1ef3 l\u00f4 theo \u0111\u1ea7u \u0111\u00edt c\u00e2m<\/h3>\nNg\u00e0y h\u00f4m nay \u0111\u1ea7u \u0111\u00edt c\u00e2m th\u00ec ng\u00e0y h\u00f4m sau l\u00f4 n\u00e0o hay n\u1ed5 nh\u1ea5t? \u0110\u00e2y l\u00e0 c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p nh\u1ea5t v\u00e0 s\u1ebd \u0111\u00e3 \u0111\u01b0\u1ee3c gi\u1ea3i \u0111\u00e1p b\u1edfi c\u00e1c chu k\u1ef3 b\u1ea1c nh\u1edb. Khi m\u1ed9t k\u1ef3 quay xu\u1ea5t hi\u1ec7n \u0111\u1ea7u \u0111\u00edt c\u00e2m th\u00ec h\u00e3y \u00e1p d\u1ee5ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p d\u1ef1 \u0111o\u00e1n d\u01b0\u1edbi \u0111\u00e2y.<\/p>\n
<\/p>\n
<\/span>a) Chu k\u1ef3 l\u00f4 theo \u0111\u1ea7u c\u00e2m<\/h4>\nC\u00e1ch t\u00ednh n\u00e0y \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng khi c\u00f3 \u0111\u1ea7u l\u00f4 c\u00e2m<\/strong> xu\u1ea5t hi\u1ec7n v\u00e0 theo c\u00e1c quy t\u1eafc b\u1ea1c nh\u1edb nh\u01b0 sau:<\/p>\n\n\u0110\u1ea7u 0<\/strong> c\u00e2m th\u00ec \u0111\u00e1nh l\u00f4 01, 09<\/strong>.<\/li>\n\u0110\u1ea7u 1<\/strong> c\u00e2m th\u00ec ch\u01a1i s\u1ed1 15, 12<\/strong>.<\/li>\n\u0110\u1ea7u 2<\/strong> c\u00e2m n\u00ean \u0111\u1ea7u t\u01b0 c\u1eb7p 23, 28<\/strong>.<\/li>\n\u0110\u1ea7u 3<\/strong> c\u00e2m th\u00ec \u0111\u00e1nh 34, 37<\/strong>.<\/li>\n\u0110\u1ea7u 4<\/strong> c\u00e2m n\u00ean ch\u01a1i s\u1ed1 46, 48<\/strong>.<\/li>\n\u0110\u1ea7u 5<\/strong> c\u00e2m b\u00e1o hi\u1ec7u l\u00f4 \u0111\u1ec1 51, 59<\/strong> s\u1ebd v\u1ec1.<\/li>\n\u0110\u1ea7u 6<\/strong> c\u00e2m th\u00ec nh\u1ea5t \u0111\u1ecbnh n\u00ean ch\u01a1i c\u1eb7p 63, 68<\/strong>.<\/li>\n\u0110\u1ea7u 7<\/strong> c\u00e2m th\u00ec m\u1ea1nh tay l\u00f4 71, 74<\/strong>.<\/li>\n\u0110\u1ea7u 8<\/strong> c\u00e2m n\u00ean xu\u1ed1ng ti\u1ec1n c\u1eb7p 82, 86<\/strong>.<\/li>\n\u0110\u1ea7u 9<\/strong> c\u00e2m kh\u00f4ng n\u00ean b\u1ecf qua 93, 98<\/strong>.<\/li>\n<\/ul>\n<\/span>b) X\u00e1c su\u1ea5t t\u00ednh l\u00f4 theo \u0111\u00edt c\u00e2m<\/h4>\nN\u1ebfu m\u1ed9t ng\u00e0y b\u1ea1n th\u1ea5y d\u1ea5u hi\u1ec7u \u0111\u00edt l\u00f4 c\u00e2m xu\u1ea5t hi\u1ec7n th\u00ec \u0111\u00f3 l\u00e0 th\u1eddi \u0111i\u1ec3m tuy\u1ec7t v\u1eddi \u0111\u1ec3 ch\u00fang \u00e1p d\u1ee5ng c\u00e1ch soi c\u1ea7u theo chu k\u1ef3 nh\u01b0 sau:<\/p>\n
\nH\u00f4m tr\u01b0\u1edbc \u0111\u00edt 0 c\u00e2m<\/strong> th\u00ec \u0111\u00e1nh c\u1eb7p 00, 80<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 1 c\u00e2m<\/strong> th\u00ec n\u00ean ch\u01a1i 21, 71<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 2 c\u00e2m<\/strong> th\u00ec ch\u1ecdn ch\u01a1i 12, 62<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 3 c\u00e2m<\/strong> th\u00ec \u0111\u00e1nh l\u00f4 \u0111\u1ec1 63, 93<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 4 c\u00e2m<\/strong> th\u00ec \u0111\u00e1nh c\u1eb7p s\u1ed1 24, 84<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 5 c\u00e2m<\/strong> n\u00ean \u0111\u1ea7u t\u01b0 v\u00e0o b\u1ed9 s\u1ed1 45, 95<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 6 c\u00e2m<\/strong> th\u00ec ch\u01a1i s\u1ed1 \u0111\u1ec1 36, 86<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 7 c\u00e2m<\/strong> n\u00ean m\u1ea1nh tay 17, 47<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 8 c\u00e2m<\/strong> th\u00ec ch\u01a1i l\u00f4 28, 58<\/strong>.<\/li>\nN\u1ebfu \u0111\u00edt 9 c\u00e2m<\/strong> th\u00ec c\u00e2n nh\u1eafc xu\u1ed1ng ti\u1ec1n c\u1eb7p 39, 69, 99<\/strong>.<\/li>\n<\/ul>\nNgo\u00e0i c\u00e1c quy lu\u1eadt n\u00e0y th\u00ec b\u1ea5t c\u1ee9 \u0111\u1ea7u \u0111u\u00f4i c\u00e2m n\u00e0o v\u1ec1 c\u0169ng c\u00f3 nhi\u1ec1u x\u00e1c su\u1ea5t tr\u00fang s\u1ed1 cao khi ch\u00fang t\u1ea5p d\u1ee5ng c\u00e1ch t\u00ednh:<\/p>\n