{"id":300308,"date":"2023-12-28T13:58:21","date_gmt":"2023-12-28T06:58:21","guid":{"rendered":"https:\/\/hoanghamobile.com\/tin-tuc\/?p=300308"},"modified":"2023-12-28T13:58:21","modified_gmt":"2023-12-28T06:58:21","slug":"cach-tinh-can-bac-2","status":"publish","type":"post","link":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/","title":{"rendered":"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 l\u00e0 m\u1ed9t l\u00fd thuy\u1ebft quan tr\u1ecdng m\u00e0 c\u00e1c b\u1ea1n h\u1ecdc sinh s\u1ebd b\u1eaft g\u1eb7p trong nh\u1eefng n\u0103m h\u1ecdc cu\u1ed1i c\u1ea5p 2. N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. V\u1eady, c\u0103n b\u1eadc 2 l\u00e0 g\u00ec? C\u00f4ng th\u1ee9c t\u00ednh c\u0103n b\u1eadc 2? H\u00e3y c\u00f9ng Ho\u00e0ng H\u00e0 Mobile t\u00ecm hi\u1ec3u qua b\u00e0i vi\u1ebft \u0111\u01b0\u1ee3c chia s\u1ebb d\u01b0\u1edbi \u0111\u00e2y!<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">L\u00fd thuy\u1ebft<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Tr\u01b0\u1edbc khi \u0111\u1ebfn v\u1edbi c\u00e1c c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, ch\u00fang ta s\u1ebd c\u00f9ng t\u00ecm hi\u1ec3u v\u1ec1 kh\u00e1i ni\u1ec7m c\u1ee7a l\u00fd thuy\u1ebft n\u00e0y.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 l\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2:\u00a0<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">Kh\u00e1i ni\u1ec7m<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 c\u1ee7a 1 s\u1ed1 a (a l\u00e0 s\u1ed1 kh\u00f4ng \u00e2m) ch\u00ednh l\u00e0 s\u1ed1 x. Trong \u0111\u00f3, x ph\u1ea3i \u0111\u00fang v\u1edbi \u0111i\u1ec1u ki\u1ec7n x\u00b2 = a.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">M\u1edf r\u1ed9ng ra, ta c\u00f3 A l\u00e0 1 bi\u1ec3u th\u1ee9c \u0111\u1ea1i s\u1ed1 b\u1ea5t k\u1ef3, th\u00ec c\u0103n b\u1eadc 2 c\u1ee7a A (\u221aA) ch\u00ednh l\u00e0 c\u0103n th\u1ee9c b\u1eadc 2 c\u1ee7a bi\u1ec3u th\u1ee9c \u0111\u00f3 v\u00e0 A \u0111\u01b0\u1ee3c hi\u1ec3u l\u00e0 bi\u1ec3u th\u1ee9c d\u01b0\u1edbi c\u0103n (hay bi\u1ec3u c\u0103n). T\u01b0\u01a1ng t\u1ef1, A ch\u1ec9 c\u00f3 ngh\u0129a khi \u0111\u00f3 l\u00e0 m\u1ed9t bi\u1ec3u th\u1ee9c kh\u00f4ng \u00e2m.\u00a0<\/span><\/p>\n<figure id=\"attachment_300311\" aria-describedby=\"caption-attachment-300311\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><picture><source srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-1.jpg.webp 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-1-300x169.jpg.webp 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-1-768x432.jpg.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" type=\"image\/webp\"><img fetchpriority=\"high\" decoding=\"async\" class=\"size-full wp-image-300311 webpexpress-processed\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-1.jpg\" alt=\"cach-tinh-can-bac-2-1\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-1.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-1-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-1-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\"><\/picture><figcaption id=\"caption-attachment-300311\" class=\"wp-caption-text\">C\u0103n b\u1eadc 2 l\u00e0 m\u1ed9t ki\u1ebfn th\u1ee9c to\u00e1n h\u1ecdc quen thu\u1ed9c trong ch\u01b0\u01a1ng tr\u00ecnh l\u1edbp 9<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400;\">\u0110\u1ec1 cho a &gt; = 0, ta c\u00f3:\u00a0<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">N\u1ebfu: x = \u221aa \u21d4 x &gt; 0 v\u00e0 x\u00b2 = a<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">N\u1ebfu: x &gt; = 0 v\u00e0 x\u00b2 = a \u21d4 x = \u221aa<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">V\u1eady, ta c\u00f3 c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2: x = \u221aa \u21d4 x &gt; = 0 v\u00e0 x\u00b2 = a.<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">So s\u00e1nh c\u0103n b\u1eadc 2<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">Trong tr\u01b0\u1eddng h\u1ee3p b\u1ea1n c\u00f3 2 s\u1ed1 a v\u00e0 b \u0111\u1ec1u l\u00e0 2 s\u1ed1 kh\u00f4ng \u00e2m v\u00e0 a &lt; b th\u00ec: \u221aa &lt; \u221ab<\/span><\/p>\n<p><span style=\"font-weight: 400;\">L\u01b0u \u00fd, v\u1edbi A l\u00e0 1 bi\u1ec3u th\u1ee9c \u21d4 \u221a(A\u00b2) = |A|:\u00a0<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221a(A\u00b2) = A n\u1ebfu A \u2265 0\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221a(A\u00b2) = &#8211; A v\u1edbi A &lt; 0<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t v\u00e0i bi\u1ebfn \u0111\u1ed5i b\u1ea1n c\u1ea7n l\u01b0u \u00fd \u0111\u1ec3 gi\u1ea3i c\u00e1c b\u00e0i to\u00e1n ch\u1ee9a bi\u1ec3u th\u1ee9c li\u00ean quan \u0111\u1ebfn c\u0103n b\u1eadc 2:\u00a0<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221aA = B \u21d4 B \u2265 0 v\u00e0 A = B\u00b2<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221a(A\u00b2) = B \u21d4 |A| = B<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221a(A\u00b2) = \u221a(B\u00b2) \u21d4 |A| = |B| \u21d4 A = B ho\u1eb7c &#8211; B<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221a(A) = \u221a(B) \u21d4 A \u2265 0 (B \u2265 0) v\u00e0 A = B.<\/span><\/li>\n<\/ul>\n<h4><span style=\"font-weight: 400;\">T\u00ednh ch\u1ea5t c\u0103n b\u1eadc 2<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">B\u1ea1n c\u1ea7n l\u01b0u \u00fd m\u1ed9t s\u1ed1 t\u00ednh ch\u1ea5t quan tr\u1ecdng \u0111\u1ec3 \u00e1p d\u1ee5ng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 nh\u01b0:\u00a0<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Kh\u00f4ng t\u1ed3n t\u1ea1i c\u0103n b\u1eadc 2 c\u1ee7a c\u00e1c s\u1ed1 \u00e2m, t\u1ee9c l\u00e0 ch\u1ec9 c\u00f3 c\u0103n b\u1eadc 2 c\u1ee7a c\u00e1c s\u1ed1 kh\u00f4ng \u00e2m, c\u00e1c s\u1ed1 \u00e2m kh\u00f4ng c\u00f3 c\u0103n b\u1eadc 2.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 c\u1ee7a 0 l\u00e0 ch\u00ednh n\u00f3: \u221a0 = 0.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">B\u1ea5t k\u1ef3 s\u1ed1 th\u1ef1c n\u00e0o kh\u00f4ng \u00e2m (\u22650) \u0111\u1ec1u c\u00f3 duy nh\u1ea5t 1 c\u0103n b\u1eadc 2 kh\u00f4ng \u00e2m.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">M\u1ed9t s\u1ed1 d\u01b0\u01a1ng s\u1ebd bao g\u1ed3m 2 v\u00e0 ch\u1ec9 c\u00f3 2 c\u0103n b\u1eadc 2 g\u1ed3m c\u00e1c s\u1ed1 tr\u00e1i d\u1ea5u nhau (s\u1ed1 \u0111\u1ed1i), s\u1ed1 d\u01b0\u01a1ng l\u00e0 \u221aa (c\u0103n b\u1eadc 2 d\u01b0\u01a1ng) v\u00e0 s\u1ed1 \u00e2m l\u00e0 -\u221aa (c\u0103n b\u1eadc 2 \u00e2m).<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 c\u0169ng c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng l\u0169y th\u1eeba: a^(\u00bd) \u0111\u1ed1i v\u1edbi s\u1ed1 d\u01b0\u01a1ng.\u00a0<\/span><\/li>\n<\/ul>\n<h3><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 l\u00fd thuy\u1ebft li\u00ean quan \u0111\u1ebfn c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc:<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">Kh\u00e1i ni\u1ec7m<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">V\u1edbi 1 s\u1ed1 d\u01b0\u01a1ng b\u1ea5t k\u1ef3 (g\u1ecdi l\u00e0 a) th\u00ec c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc c\u1ee7a a s\u1ebd \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng \u221aa. Trong to\u00e1n h\u1ecdc, c\u00f3 1 tr\u01b0\u1eddng h\u1ee3p \u0111\u1eb7c bi\u1ec7t l\u00e0 s\u1ed1 0 l\u00e0 c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc c\u1ee7a ch\u00ednh n\u00f3.\u00a0<\/span><\/p>\n<figure id=\"attachment_300312\" aria-describedby=\"caption-attachment-300312\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><picture><source srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-2.jpg.webp 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-2-300x169.jpg.webp 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-2-768x432.jpg.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" type=\"image\/webp\"><img decoding=\"async\" class=\"size-full wp-image-300312 webpexpress-processed\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-2.jpg\" alt=\"cach-tinh-can-bac-2-2\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-2.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-2-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-2-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\"><\/picture><figcaption id=\"caption-attachment-300312\" class=\"wp-caption-text\">V\u1edbi 1 s\u1ed1 d\u01b0\u01a1ng b\u1ea5t k\u1ef3 th\u00ec c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc c\u1ee7a a s\u1ebd \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng \u221a<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400;\">V\u1edbi a \u2265 0:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">x = \u221aa \u21d4 x \u2265 0 v\u00e0 x\u00b2 = a.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">x \u2265 0 v\u00e0 x\u00b2 = a \u21d4 x = \u221aa<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">Khi so s\u00e1nh, ta c\u00f3: a v\u00e0 b l\u00e0 2 s\u1ed1 kh\u00f4ng \u00e2m: a &gt; b \u21d4 \u221aa &gt; \u221ab<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">V\u00ed d\u1ee5 v\u1ec1 c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc:<\/span><\/h4>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc c\u1ee7a 25 l\u00e0 \u221a25 = \u221a5\u00b2 = 5<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">T\u00ecm c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc c\u1ee7a 25, 64, 100, 121 v\u00e0 10000: \u221a25 = 5, \u221a64 = 8, \u221a100 = 10, \u221a121 = 11, \u221a10000 = 100.\u00a0<\/span><\/li>\n<\/ul>\n<h4><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 nguy\u00ean d\u01b0\u01a1ng<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">1 s\u1ed1 nguy\u00ean d\u01b0\u01a1ng c\u00f3 2 c\u0103n b\u1eadc 2 l\u00e0 2 s\u1ed1 \u0111\u1ed1i (s\u1ed1 tr\u00e1i d\u1ea5u nhau, v\u00ed d\u1ee5 nh\u01b0 \u221aa v\u00e0 -\u221aa). Tuy nhi\u00ean, khi \u0111\u1ec1 c\u1eadp \u0111\u1ebfn c\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 nguy\u00ean d\u01b0\u01a1ng, ch\u00fang ta th\u01b0\u1eddng t\u1ef1 hi\u1ec3u \u0111\u00f3 l\u00e0 c\u0103n b\u1eadc 2 d\u01b0\u01a1ng.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">C\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 nguy\u00ean d\u01b0\u01a1ng s\u1ebd b\u1eb1ng c\u0103n b\u1eadc 2 c\u1ee7a t\u00edch c\u00e1c th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1: \u221a(a x b) = \u221aa x \u221ab (v\u00ed d\u1ee5: \u221a12 = \u221a(6 x 2) = \u221a6 x \u221a2<\/span><\/p>\n<p><span style=\"font-weight: 400;\">B\u1ea3ng d\u01b0\u1edbi \u0111\u00e2y l\u00e0 c\u0103n b\u1eadc 2 c\u1ee7a c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean t\u1eeb 0 &#8211; 10:\u00a0<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">n<\/span><\/td>\n<td><span style=\"font-weight: 400;\">\u221an<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">0<\/span><\/td>\n<td><span style=\"font-weight: 400;\">0<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">1<\/span><\/td>\n<td><span style=\"font-weight: 400;\">1<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">2<\/span><\/td>\n<td><span style=\"font-weight: 400;\">1,414<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">3<\/span><\/td>\n<td><span style=\"font-weight: 400;\">1,732<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">4<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">5<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2,236<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">6<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2,449<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">7<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2,646<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">8<\/span><\/td>\n<td><span style=\"font-weight: 400;\">2,828<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">9<\/span><\/td>\n<td><span style=\"font-weight: 400;\">3<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">10<\/span><\/td>\n<td><span style=\"font-weight: 400;\">3,162<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4><span style=\"font-weight: 400;\"> C\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 ph\u1ee9c, s\u1ed1 \u00e2m<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">M\u1ecdi s\u1ed1 (d\u00f9 l\u00e0 \u00e2m hay d\u01b0\u01a1ng) khi b\u00ecnh ph\u01b0\u01a1ng l\u00ean \u0111\u1ec1u s\u1ebd cho ra m\u1ed9t s\u1ed1 d\u01b0\u01a1ng, duy ch\u1ec9 c\u00f3 0 b\u00ecnh ph\u01b0\u01a1ng l\u00ean v\u1eabn b\u1eb1ng 0, v\u00e0 tr\u00ean th\u1ef1c t\u1ebf kh\u00f4ng c\u00f3 b\u1ea5t k\u1ef3 s\u1ed1 \u00e2m n\u00e0o l\u00e0 c\u00f3 c\u0103n b\u1eadc 2, m\u00e0 n\u00f3 ch\u1ec9 t\u1ed3n t\u1ea1i trong t\u1eadp s\u1ed1 ph\u1ee9c.\u00a0<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Ph\u00e9p khai ph\u01b0\u01a1ng<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">\u0110\u1ec3 \u00e1p d\u1ee5ng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n c\u1ea7n hi\u1ec3u r\u00f5 v\u1ec1 ph\u00e9p khai ph\u01b0\u01a1ng. Ph\u00e9p khai ph\u01b0\u01a1ng \u0111\u01b0\u1ee3c hi\u1ec3u l\u00e0 d\u1ea1ng to\u00e1n t\u00ecm ki\u1ebfm c\u0103n b\u1eadc 2 s\u1ed1 h\u1ecdc c\u1ee7a 1 s\u1ed1 l\u1edbn h\u01a1n 0 ( \u22650 hay s\u1ed1 kh\u00f4ng \u00e2m).\u00a0<\/span><\/p>\n<figure id=\"attachment_300313\" aria-describedby=\"caption-attachment-300313\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><picture><source srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-3.jpg.webp 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-3-300x169.jpg.webp 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-3-768x432.jpg.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" type=\"image\/webp\"><img decoding=\"async\" class=\"size-full wp-image-300313 webpexpress-processed\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-3.jpg\" alt=\"cach-tinh-can-bac-2-3\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-3.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-3-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-3-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\"><\/picture><figcaption id=\"caption-attachment-300313\" class=\"wp-caption-text\">Ph\u00e9p khai ph\u01b0\u01a1ng \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng nhi\u1ec1u trong c\u00e1c b\u00e0i to\u00e1n v\u1ec1 c\u0103n b\u1eadc 2<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5: \u0110\u1ec1 cho a \u2265 0 v\u00e0 (a)\u00b2 = 25, th\u00ec ta c\u00f3 th\u1ec3 t\u00ednh ra a = \u00b1\u221a25<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">M\u1ed9t s\u1ed1 l\u01b0u \u00fd c\u1ea7n nh\u1edb khi \u00e1p d\u1ee5ng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2<\/span><\/h3>\n<table>\n<tbody>\n<tr>\n<td><span style=\"font-weight: 400;\">Khi c\u00f3:\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">a \u2265 0 =&gt; a = ((\u221aa))\u00b2.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">a \u2265 0, c\u00f3 x \u2265 0 v\u00e0 x\u00b2 = a =&gt; x = \u221aa.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">a \u2265 0, c\u00f3 x \u2265 0 v\u00e0 x\u00b2 = a =&gt; x = \u00b1\u221aa.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><span style=\"font-weight: 400;\">M\u1ed9t s\u1ed1 d\u1ea1ng b\u00e0i to\u00e1n l\u1edbp 9 c\u1ea7n \u00e1p d\u1ee5ng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2\u00a0<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 d\u1ea1ng b\u00e0i li\u00ean quan \u0111\u1ebfn c\u0103n b\u1eadc 2 m\u00e0 c\u00e1c b\u1ea1n h\u1ecdc sinh s\u1ebd g\u1eb7p trong ch\u01b0\u01a1ng tr\u00ecnh to\u00e1n h\u1ecdc \u0110\u1ea1i s\u1ed1 l\u1edbp 9. Th\u00f4ng th\u01b0\u1eddng, c\u00e1ch gi\u1ea3i s\u1ebd ch\u1ec9 xoay quanh l\u00fd thuy\u1ebft, t\u00ednh ch\u1ea5t c\u1ee7a c\u0103n b\u1eadc 2 v\u00e0 m\u1ed9t s\u1ed1 h\u1eb1ng \u0111\u1eb3ng th\u1ee9c li\u00ean quan. V\u1eady n\u00ean, \u0111i\u1ec1u quan tr\u1ecdng nh\u1ea5t l\u00e0 b\u1ea1n ph\u1ea3i n\u1eafm r\u00f5 nh\u1eefng ki\u1ebfn th\u1ee9c c\u01a1 b\u1ea3n \u0111\u1ec3 c\u00f3 th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n n\u00e2ng cao h\u01a1n:<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">D\u1ea1ng th\u1ee9 nh\u1ea5t: T\u00ecm v\u00e0 so s\u00e1nh 2 c\u0103n b\u1eadc 2<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">V\u1edbi d\u1ea1ng to\u00e1n n\u00e0y, \u0111\u1ec1 th\u01b0\u1eddng y\u00eau c\u1ea7u b\u1ea1n t\u00ecm m\u1ed9t trong 2 s\u1ed1 ho\u1eb7c so s\u00e1nh v\u1ebf n\u00e0o l\u1edbn h\u01a1n trong bi\u1ec3u th\u1ee9c. \u0110\u1ec3 l\u00e0m \u0111\u01b0\u1ee3c, b\u1ea1n ch\u1ec9 c\u1ea7n n\u1eafm v\u1eefng bi\u1ec3u th\u1ee9c sau:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">a &gt; b \u21d4 \u221aa &gt; \u221ab<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Trong \u0111\u00f3, a v\u00e0 b \u0111\u1ec1u l\u00e0 2 s\u1ed1 l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng 0 (hai s\u1ed1 kh\u00f4ng \u00e2m).<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">D\u1ea1ng th\u1ee9 hai: T\u00ecm gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c c\u00f3 ch\u1ee9a c\u0103n b\u1eadc 2<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">Trong d\u1ea1ng n\u00e0y, b\u1ea1n c\u1ea7n \u00e1p d\u1ee5ng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 v\u1edbi h\u1eb1ng \u0111\u1eb3ng th\u1ee9c c\u01a1 b\u1ea3n sau:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Ta c\u00f3:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">N\u1ebfu A\u2265 0 =&gt; \u221aA\u00b2 = |A| = A<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">N\u1ebfu A &lt; 0 =&gt; \u221aA\u00b2 = |A| = &#8211; A<\/span><span style=\"font-weight: 400;\">\u00a0<\/span><\/li>\n<\/ul>\n<p><picture><source srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-4.jpg.webp 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-4-300x169.jpg.webp 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-4-768x432.jpg.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" type=\"image\/webp\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-300314 webpexpress-processed\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-4.jpg\" alt=\"cach-tinh-can-bac-2-4\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-4.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-4-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-4-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\"><\/picture><\/p>\n<h4><span style=\"font-weight: 400;\">D\u1ea1ng th\u1ee9 ba: R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">D\u1ea1ng n\u00e0y s\u1ebd y\u00eau c\u1ea7u b\u1ea1n r\u00fat g\u1ecdn ph\u1ea7n bi\u1ec3u th\u1ee9c c\u00f3 ch\u1ee9a c\u0103n b\u1eadc 2. \u0110\u00e2y l\u00e0 d\u1ea1ng t\u01b0\u01a1ng \u0111\u1ed1i kh\u00f3 trong to\u00e1n l\u1edbp 9 v\u00e0 b\u1ea1n c\u1ea7n \u00e1p d\u1ee5ng m\u1ed9t s\u1ed1 h\u1eb1ng \u0111\u1eb3ng th\u1ee9c li\u00ean quan \u0111\u1ec3 gi\u1ea3i to\u00e1n nh\u01b0:\u00a0<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">a\u00b2 + 2ab + b\u00b2 = (a + b)\u00b2<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">a\u00b2 \u2013 2ab + b\u00b2 = (a \u2013 b)\u00b2\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">N\u1ebfu A \u2265 0 =&gt; \u221aA\u00b2 = |A| = A ho\u1eb7c A &lt; 0 =&gt; \u221aA\u00b2 = |A| = &#8211; A<\/span><span style=\"font-weight: 400;\">\u00a0<\/span><\/li>\n<\/ul>\n<h4><span style=\"font-weight: 400;\">D\u1ea1ng th\u1ee9 t\u01b0: T\u00ecm \u0111i\u1ec1u ki\u1ec7n th\u1ecfa m\u00e3n ph\u1ea7n bi\u1ec3u th\u1ee9c ch\u1ee9a c\u0103n b\u1eadc 2 c\u00f3 ngh\u0129a<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">D\u1ea1ng to\u00e1n n\u00e0y y\u00eau c\u1ea7u ng\u01b0\u1eddi l\u00e0m ph\u1ea3i t\u00ecm c\u00e1c \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 bi\u1ec3u th\u1ee9c d\u01b0\u1edbi c\u0103n c\u00f3 ngh\u0129a. N\u1ebfu mu\u1ed1n bi\u1ec3u th\u1ee9c d\u01b0\u1edbi c\u0103n c\u00f3 ngh\u0129a, bi\u1ec3u th\u1ee9c \u0111\u00f3 bu\u1ed9c ph\u1ea3i c\u00f3 gi\u00e1 tr\u1ecb kh\u00f4ng \u00e2m. Khi \u0111\u00f3 ta c\u00f3: \u221aA ch\u1ec9 c\u00f3 ngh\u0129a khi A \u2265 0.<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">D\u1ea1ng th\u1ee9 n\u0103m: Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh (bi\u1ec3u th\u1ee9c) c\u00f3 ch\u1ee9a c\u0103n b\u1eadc hai<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">D\u1ea1ng n\u00e0y s\u1ebd y\u00eau c\u1ea7u b\u1ea1n gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh m\u00e0 trong \u0111\u00f3 c\u00f3 bi\u1ec3u th\u1ee9c ch\u1ee9a c\u0103n b\u1eadc hai. L\u00fac n\u00e0y, b\u1ea1n n\u1eafm v\u1eefng v\u00e0 v\u1eadn d\u1ee5ng t\u1ed1t c\u00e1c ki\u1ebfn th\u1ee9c c\u01a1 b\u1ea3n sau:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221aA = B \u21d4 B \u2265 0 v\u00e0 A = B\u00b2.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221aA\u00b2 = B \u21d4 |A| = B.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221aA = \u221aB \u21d4 A \u2265 0 (B \u2265 0) v\u00e0 A = B.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">\u221aA\u00b2 = \u221aB\u00b2 \u21d4 |A| = |B| \u21d4 A = \u00b1 B.<\/span><\/li>\n<\/ul>\n<h2><span style=\"font-weight: 400;\">M\u1eb9o t\u00ecm c\u0103n b\u1eadc 2 \u0111\u01a1n gi\u1ea3n, kh\u00f4ng c\u1ea7n m\u00e1y t\u00ednh<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Ngo\u00e0i nh\u1eefng l\u00fd thuy\u1ebft v\u00e0 c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 v\u1edbi m\u1ed9t s\u1ed1 d\u1ea1ng quen thu\u1ed9c tr\u00ean, b\u1ea1n c\u0169ng c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng c\u00e1c m\u1eb9o hay d\u01b0\u1edbi \u0111\u00e2y \u0111\u1ec3 t\u00ecm c\u0103n b\u1eadc 2 m\u00e0 kh\u00f4ng c\u1ea7n \u0111\u1ebfn m\u00e1y t\u00ednh. \u0110\u00e2y l\u00e0 c\u00e1ch r\u00e8n t\u01b0 duy kh\u00e1 hi\u1ec7u qu\u1ea3, gi\u00fap b\u1ea1n ph\u1ea3n \u1ee9ng nhanh h\u01a1n v\u1edbi c\u00e1c con s\u1ed1 v\u00e0 th\u1ef1c hi\u1ec7n t\u00ednh to\u00e1n m\u1ed9t c\u00e1ch \u0111\u01a1n gi\u1ea3n, d\u1ec5 d\u00e0ng nh\u1ea5t.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">M\u1eb9o t\u00ednh c\u0103n b\u1eadc 2 c\u1ee7a 1 s\u1ed1 nguy\u00ean<\/span><\/h3>\n<p>T\u00ednh c\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 nguy\u00ean th\u01b0\u1eddng \u0111\u01a1n gi\u1ea3n v\u00e0 d\u1ec5 th\u1ef1c hi\u1ec7n h\u01a1n r\u1ea5t nhi\u1ec1u so v\u1edbi s\u1ed1 kh\u00f4ng nguy\u00ean. \u0110\u1ec3 <span style=\"font-weight: 400;\">t\u00ecm c\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 nguy\u00ean m\u00e0 kh\u00f4ng c\u1ea7n d\u1ebfn m\u00e1y t\u00ednh, b\u1ea1n c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng m\u1ed9t trong 2 c\u00e1ch sau:<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">C\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 b\u1eb1ng c\u00e1ch nh\u00e2n<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">\u0110\u01b0\u1ee3c bi\u1ebft, c\u0103n b\u1eadc 2 c\u1ee7a a l\u00e0 m\u1ed9t s\u1ed1 b, m\u00e0 khi b\u1ea1n d\u00f9ng s\u1ed1 \u0111\u00f3 nh\u00e2n v\u1edbi ch\u00ednh n\u00f3 (t\u1ee9c l\u00e0 b x b) s\u1ebd b\u1eb1ng v\u1edbi s\u1ed1 a ban \u0111\u1ea7u. Ch\u1eb3ng h\u1ea1n nh\u01b0: \u221a25 = \u221a(5 x 5) = 5. L\u00fac n\u00e0y, b\u1ea1n c\u00f3 th\u1ec3 t\u1ef1 h\u1ecfi ch\u00ednh m\u00ecnh, li\u1ec7u c\u00f3 m\u1ed9t s\u1ed1 n\u00e0o m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 nh\u00e2n v\u1edbi ch\u00ednh n\u00f3 \u0111\u1ec3 ra s\u1ed1 m\u00ecnh \u0111ang c\u00f3 hay kh\u00f4ng.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5 nh\u01b0: C\u0103n b\u1eadc 2 c\u1ee7a 1 = 1 (v\u00ec 1 x 1 = 1), nh\u01b0ng c\u0103n b\u1eadc 2 c\u1ee7a 25 l\u1ea1i l\u00e0 5 (v\u00ec 5 x 5 = 25). T\u01b0\u01a1ng t\u1ef1, c\u0103n b\u1eadc 2 c\u1ee7a 4 l\u00e0 2, c\u1ee7a 9 l\u00e0 3, c\u1ee7a 16 l\u00e0 4, c\u1ee7a 36 l\u00e0 6, c\u1ee7a 49 l\u00e0 7\u2026\u00a0<\/span><\/p>\n<figure id=\"attachment_300315\" aria-describedby=\"caption-attachment-300315\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><picture><source srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-5.jpg.webp 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-5-300x169.jpg.webp 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-5-768x432.jpg.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" type=\"image\/webp\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-300315 webpexpress-processed\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-5.jpg\" alt=\"cach-tinh-can-bac-2-5\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-5.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-5-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-5-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\"><\/picture><figcaption id=\"caption-attachment-300315\" class=\"wp-caption-text\">B\u1ea1n v\u1eabn c\u00f3 th\u1ec3 t\u00ecm ra c\u0103n b\u1eadc 2 c\u1ee7a m\u1ed9t s\u1ed1 nguy\u00ean m\u00e0 kh\u00f4ng c\u1ea7n m\u00e1y t\u00ednh<\/figcaption><\/figure>\n<h4><span style=\"font-weight: 400;\">C\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 b\u1eb1ng c\u00e1ch chia<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">T\u01b0\u01a1ng t\u1ef1, b\u1ea1n c\u0169ng c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng ph\u00e9p chia \u0111\u1ec3 t\u00ecm c\u0103n b\u1eadc 2 b\u1eb1ng c\u00e1ch chia l\u1ea7n l\u01b0\u1ee3t s\u1ed1 nguy\u00ean m\u00e0 m\u00ecnh c\u00f3 cho c\u00e1c s\u1ed1 kh\u00e1c cho \u0111\u1ebfn khi c\u00f3 \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0 1 s\u1ed1 th\u01b0\u01a1ng b\u1eb1ng v\u1edbi ch\u00ednh s\u1ed1 chia. Ch\u1eb3ng h\u1ea1n nh\u01b0 16\/4 = 4, 25\/5 = 5, 4\/2 = 2\u2026<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">M\u1eb9o t\u00ecm c\u0103n b\u1eadc 2 c\u1ee7a c\u00e1c s\u1ed1 kh\u00e1c<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o b\u1ea1n c\u0169ng s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c \u0111\u1ec1 b\u00e0i l\u00e0 m\u1ed9t s\u1ed1 nguy\u00ean. V\u1eady n\u1ebfu \u0111\u00f3 l\u00e0 s\u1ed1 kh\u00f4ng nguy\u00ean th\u00ec sao? C\u00e1c b\u01b0\u1edbc th\u1ef1c hi\u1ec7n s\u1ebd kh\u00f3 h\u01a1n ch\u00fat, nh\u01b0ng b\u1ea1n v\u1eabn c\u00f3 th\u1ec3 l\u00e0m \u0111\u01b0\u1ee3c b\u1eb1ng c\u00e1ch:\u00a0<\/span><\/p>\n<figure id=\"attachment_300316\" aria-describedby=\"caption-attachment-300316\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><picture><source srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-6.jpg.webp 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-6-300x169.jpg.webp 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/webp-express\/webp-images\/uploads\/2023\/12\/cach-tinh-can-bac-2-6-768x432.jpg.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" type=\"image\/webp\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-300316 webpexpress-processed\" src=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-6.jpg\" alt=\"cach-tinh-can-bac-2-6\" width=\"800\" height=\"450\" srcset=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-6.jpg 800w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-6-300x169.jpg 300w, https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2-6-768x432.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\"><\/picture><figcaption id=\"caption-attachment-300316\" class=\"wp-caption-text\">C\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 kh\u00f4ng nguy\u00ean ph\u1ee9c t\u1ea1p h\u01a1n \u0111\u00f4i ch\u00fat<\/figcaption><\/figure>\n<h4><span style=\"font-weight: 400;\">C\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p lo\u1ea1i tr\u1eeb<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">B\u1ea1n c\u00f3 th\u1ec3 h\u00ecnh dung qua v\u00ed d\u1ee5 sau:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">B\u1ea1n c\u1ea7n t\u00ecm c\u0103n b\u1eadc 2 c\u1ee7a 20. Trong \u0111\u00f3, ta c\u00f3 c\u0103n b\u1eadc 2 c\u1ee7a 20 c\u00f3 gi\u00e1 tr\u1ecb n\u1eb1m gi\u1eefa c\u0103n b\u1eadc 2 c\u1ee7a 25 v\u00e0 16 v\u1edbi gi\u00e1 tr\u1ecb l\u1ea7n l\u01b0\u1ee3t l\u00e0 5, 4. V\u1eady, \u01b0\u1edbc ch\u1eebng c\u0103n b\u1eadc 2 c\u1ee7a 20 c\u00f3 th\u1ec3 b\u1eb1ng 4.5. B\u00e2y gi\u1edd, b\u1ea1n l\u1ea5y 4.5 x 4.5, \u0111\u00e1p \u00e1n s\u1ebd l\u1edbn h\u01a1n 20, v\u1eady b\u1ea1n c\u00f3 th\u1ec3 gi\u1ea3m xu\u1ed1ng th\u00e0nh 4.4. \u0110\u1ed1i v\u1edbi tr\u01b0\u1eddng h\u1ee3p k\u1ebft qu\u1ea3 ra s\u1ed1 nh\u1ecf h\u01a1n, b\u1ea1n c\u0169ng c\u00f3 th\u1ec3 t\u0103ng l\u00ean m\u1ed9t ch\u00fat l\u00e0 \u0111\u01b0\u1ee3c.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">4.4 x 4.4 s\u1ebd \u0111\u01b0\u1ee3c 19.36, l\u00fac n\u00e0y ph\u1ea1m vi s\u1ebd \u0111\u01b0\u1ee3c thu h\u1eb9p trong kho\u1ea3ng 4.5 &#8211; 4.4. Khi b\u1ea1n \u01b0\u1edbc ch\u1eebng kho\u1ea3ng 4.445, ta nh\u00e2n ch\u00fang v\u1edbi nhau s\u1ebd ra \u0111\u00e1p \u00e1n g\u1ea7n b\u1eb1ng 20. C\u1ee9 ti\u1ebfp t\u1ee5c cho \u0111\u1ebfn khi \u0111\u1ea1t \u0111\u01b0\u1ee3c con s\u1ed1 g\u1ea7n b\u1eb1ng 20 nh\u1ea5t l\u00e0 4.475 (ra k\u1ebft qu\u1ea3 20.03), \u0111\u00e2y l\u00e0 k\u1ebft qu\u1ea3 g\u1ea7n \u0111\u00fang sau khi l\u00e0m tr\u00f2n.\u00a0<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">C\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 v\u1edbi ph\u01b0\u01a1ng ph\u00e1p trung b\u00ecnh<\/span><\/h4>\n<p>\u0110\u1ec3 t\u00ednh c\u0103n b\u1eadc 2 v\u1edbi ph\u01b0\u01a1ng ph\u00e1p trung b\u00ecnh, b\u1ea1n c\u1ea7n ch\u1ecdn 2 s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng g\u1ea7n nh\u1ea5t v\u1edbi s\u1ed1 \u0111\u01b0\u1ee3c cho, sau \u0111\u00f3 l\u1ea5y s\u1ed1 \u0111\u01b0\u1ee3c cho (g\u1ecdi l\u00e0 x) chia cho c\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng \u0111\u01b0\u1ee3c ch\u1ecdn (g\u1ecdi l\u00e0 y). L\u00fac n\u00e0y, b\u1ea1n s\u1ebd thu \u0111\u01b0\u1ee3c m\u1ed9t s\u1ed1 z, h\u00e3y t\u00ednh trung b\u00ecnh c\u1ed9ng c\u1ee7a y v\u00e0 z \u0111\u1ec3 cho ra m\u1ed9t s\u1ed1 n, sau \u0111\u00f3 l\u1eb7p l\u1ea1i qu\u00e1 tr\u00ecnh tr\u00ean cho \u0111\u1ebfn khi t\u00ecm \u0111\u01b0\u1ee3c 1 s\u1ed1 (g\u1ecdi l\u00e0 h) m\u00e0 khi ta l\u1ea5y h x h s\u1ebd cho ra m\u1ed9t s\u1ed1 g\u1ea7n b\u1eb1ng v\u1edbi x.<\/p>\n<p><span style=\"font-weight: 400;\">C\u00e1ch n\u00e0y kh\u00e1 r\u1eafc r\u1ed1i,\u00a0<\/span><span style=\"font-weight: 400;\">nh\u01b0ng b\u1ea1n c\u00f3 th\u1ec3 d\u1ec5 h\u00ecnh dung h\u01a1n v\u1edbi v\u00ed d\u1ee5 sau:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Ch\u1eb3ng h\u1ea1n nh\u01b0 \u0111\u1ec3 t\u00ecm c\u0103n b\u1eadc 2 c\u1ee7a s\u1ed1 10, ta th\u1ef1c hi\u1ec7n theo c\u00e1ch t\u00ednh sau:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Ch\u1ecdn s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng g\u1ea7n v\u1edbi 10 l\u00e0 s\u1ed1 9.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Ta s\u1ebd chia 10 cho c\u0103n b\u1eadc 2 c\u1ee7a 9 v\u00e0 thu \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0 3.33.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Ti\u1ebfp t\u1ee5c t\u00ecm trung b\u00ecnh c\u1ed9ng gi\u1eefa 3 v\u00e0 3.33, ta c\u00f3 3.1667.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">L\u1eb7p l\u1ea1i qu\u00e1 tr\u00ecnh b\u00ean tr\u00ean b\u1eb1ng c\u00e1ch chia 10 cho 3.1667 v\u00e0 t\u00ecm trung b\u00ecnh c\u1ed9ng.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">B\u00e2y gi\u1edd, b\u1ea1n ki\u1ec3m tra l\u1ea1i k\u1ebft qu\u1ea3 b\u1eb1ng c\u00e1ch l\u1ea5y 3.1667 x 3.1667 s\u1ebd ra 10.001 =&gt; \u0111\u00e2y l\u00e0 k\u1ebft qu\u1ea3 cu\u1ed1i c\u00f9ng.\u00a0<\/span><\/li>\n<\/ul>\n<h3>L\u1eddi k\u1ebft<\/h3>\n<p><span style=\"font-weight: 400;\">\u0110\u00f3 l\u00e0 l\u00fd thuy\u1ebft v\u00e0 c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2 m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o. Trong ch\u01b0\u01a1ng tr\u00ecnh to\u00e1n h\u1ecdc c\u1ea5p 2, \u0111\u00e2y l\u00e0 d\u1ea1ng b\u00e0i t\u1eadp kh\u00e1 kh\u00f3 v\u00e0 c\u00f3 nhi\u1ec1u b\u00e0i to\u00e1n n\u00e2ng cao. V\u1eady n\u00ean, h\u00e3y n\u1eafm ch\u1eafc ki\u1ebfn th\u1ee9c c\u01a1 b\u1ea3n \u0111\u1ec3 d\u1ec5 d\u00e0ng chinh ph\u1ee5c n\u1ed9i dung ki\u1ebfn th\u1ee9c n\u00e0y, b\u1ea1n nh\u00e9!<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Xem th\u00eam:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><strong><a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/giai-phuong-trinh-bac-2\/\">C\u00e1ch gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc 2 nhanh ch\u00f3ng nh\u1ea5t<\/a><\/strong><\/li>\n<li style=\"font-weight: 400;\"><strong><a href=\"https:\/\/hoanghamobile.com\/tin-tuc\/dien-tich-hinh-chu-nhat\/\">C\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch h\u00ecnh ch\u1eef nh\u1eadt ch\u00ednh x\u00e1c nh\u1ea5t<\/a><\/strong><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>C\u0103n b\u1eadc 2 l\u00e0 m\u1ed9t l\u00fd thuy\u1ebft quan tr\u1ecdng m\u00e0 c\u00e1c b\u1ea1n h\u1ecdc sinh s\u1ebd b\u1eaft g\u1eb7p trong nh\u1eefng n\u0103m h\u1ecdc cu\u1ed1i c\u1ea5p 2. N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. V\u1eady, c\u0103n b\u1eadc 2 l\u00e0 [&hellip;]<\/p>\n","protected":false},"author":97,"featured_media":300310,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3910,30453],"tags":[],"class_list":["post-300308","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-kham-pha","category-kien-thuc"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v24.2 (Yoast SEO v24.2) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2<\/title>\n<meta name=\"description\" content=\"N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. T\u00ecm hi\u1ec3u t\u1ea1i \u0111\u00e2y!\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\" \/>\n<meta property=\"og:locale\" content=\"vi_VN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2\" \/>\n<meta property=\"og:description\" content=\"N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. T\u00ecm hi\u1ec3u t\u1ea1i \u0111\u00e2y!\" \/>\n<meta property=\"og:url\" content=\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\" \/>\n<meta property=\"og:site_name\" content=\"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/hoanghamobilecom\" \/>\n<meta property=\"article:published_time\" content=\"2023-12-28T06:58:21+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"628\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u0110\u01b0\u1ee3c vi\u1ebft b\u1edfi\" \/>\n\t<meta name=\"twitter:data1\" content=\"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u01af\u1edbc t\u00ednh th\u1eddi gian \u0111\u1ecdc\" \/>\n\t<meta name=\"twitter:data2\" content=\"15 ph\u00fat\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\"},\"author\":{\"name\":\"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/person\/bd62b9b9f8624b34df49eb671db6853a\"},\"headline\":\"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2\",\"datePublished\":\"2023-12-28T06:58:21+00:00\",\"dateModified\":\"2023-12-28T06:58:21+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\"},\"wordCount\":3153,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#organization\"},\"image\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg\",\"articleSection\":[\"Kh\u00e1m Ph\u00e1\",\"Ki\u1ebfn Th\u1ee9c\"],\"inLanguage\":\"vi\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#respond\"]}],\"copyrightYear\":\"2023\",\"copyrightHolder\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#organization\"}},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\",\"url\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\",\"name\":\"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2\",\"isPartOf\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg\",\"datePublished\":\"2023-12-28T06:58:21+00:00\",\"dateModified\":\"2023-12-28T06:58:21+00:00\",\"description\":\"N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. T\u00ecm hi\u1ec3u t\u1ea1i \u0111\u00e2y!\",\"breadcrumb\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#breadcrumb\"},\"inLanguage\":\"vi\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"vi\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage\",\"url\":\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg\",\"contentUrl\":\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg\",\"width\":1200,\"height\":628,\"caption\":\"cach-tinh-can-bac-2\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Trang ch\u1ee7\",\"item\":\"https:\/\/hoanghamobile.com\/tin-tuc\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Kh\u00e1m Ph\u00e1\",\"item\":\"https:\/\/hoanghamobile.com\/tin-tuc\/category\/kham-pha\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#website\",\"url\":\"https:\/\/hoanghamobile.com\/tin-tuc\/\",\"name\":\"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/hoanghamobile.com\/tin-tuc\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"vi\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#organization\",\"name\":\"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile\",\"url\":\"https:\/\/hoanghamobile.com\/tin-tuc\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"vi\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2021\/12\/logo-text.png\",\"contentUrl\":\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2021\/12\/logo-text.png\",\"width\":256,\"height\":37,\"caption\":\"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile\"},\"image\":{\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/hoanghamobilecom\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/person\/bd62b9b9f8624b34df49eb671db6853a\",\"name\":\"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"vi\",\"@id\":\"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/74bcebffab89aeb362901537cb11326b?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/74bcebffab89aeb362901537cb11326b?s=96&d=mm&r=g\",\"caption\":\"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean\"},\"url\":\"https:\/\/hoanghamobile.com\/tin-tuc\/author\/nguyen-thi-my-lien\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2","description":"N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. T\u00ecm hi\u1ec3u t\u1ea1i \u0111\u00e2y!","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/","og_locale":"vi_VN","og_type":"article","og_title":"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2","og_description":"N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. T\u00ecm hi\u1ec3u t\u1ea1i \u0111\u00e2y!","og_url":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/","og_site_name":"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile","article_publisher":"https:\/\/www.facebook.com\/hoanghamobilecom","article_published_time":"2023-12-28T06:58:21+00:00","og_image":[{"width":1200,"height":628,"url":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg","type":"image\/jpeg"}],"author":"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean","twitter_card":"summary_large_image","twitter_misc":{"\u0110\u01b0\u1ee3c vi\u1ebft b\u1edfi":"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean","\u01af\u1edbc t\u00ednh th\u1eddi gian \u0111\u1ecdc":"15 ph\u00fat"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#article","isPartOf":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/"},"author":{"name":"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/person\/bd62b9b9f8624b34df49eb671db6853a"},"headline":"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2","datePublished":"2023-12-28T06:58:21+00:00","dateModified":"2023-12-28T06:58:21+00:00","mainEntityOfPage":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/"},"wordCount":3153,"commentCount":0,"publisher":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#organization"},"image":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage"},"thumbnailUrl":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg","articleSection":["Kh\u00e1m Ph\u00e1","Ki\u1ebfn Th\u1ee9c"],"inLanguage":"vi","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#respond"]}],"copyrightYear":"2023","copyrightHolder":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#organization"}},{"@type":"WebPage","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/","url":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/","name":"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2","isPartOf":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#website"},"primaryImageOfPage":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage"},"image":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage"},"thumbnailUrl":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg","datePublished":"2023-12-28T06:58:21+00:00","dateModified":"2023-12-28T06:58:21+00:00","description":"N\u1ebfu kh\u00f4ng n\u1eafm v\u1eefng c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2, b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c c\u00e1c b\u00e0i to\u00e1n kh\u00f3 h\u01a1n li\u00ean quan \u0111\u1ebfn ki\u1ebfn th\u1ee9c n\u00e0y. T\u00ecm hi\u1ec3u t\u1ea1i \u0111\u00e2y!","breadcrumb":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#breadcrumb"},"inLanguage":"vi","potentialAction":[{"@type":"ReadAction","target":["https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/"]}]},{"@type":"ImageObject","inLanguage":"vi","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#primaryimage","url":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg","contentUrl":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2023\/12\/cach-tinh-can-bac-2.jpg","width":1200,"height":628,"caption":"cach-tinh-can-bac-2"},{"@type":"BreadcrumbList","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tinh-can-bac-2\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Trang ch\u1ee7","item":"https:\/\/hoanghamobile.com\/tin-tuc\/"},{"@type":"ListItem","position":2,"name":"Kh\u00e1m Ph\u00e1","item":"https:\/\/hoanghamobile.com\/tin-tuc\/category\/kham-pha\/"},{"@type":"ListItem","position":3,"name":"L\u00fd thuy\u1ebft v\u1ec1 c\u0103n b\u1eadc 2, c\u00e1ch t\u00ednh c\u0103n b\u1eadc 2"}]},{"@type":"WebSite","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#website","url":"https:\/\/hoanghamobile.com\/tin-tuc\/","name":"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile","description":"","publisher":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/hoanghamobile.com\/tin-tuc\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"vi"},{"@type":"Organization","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#organization","name":"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile","url":"https:\/\/hoanghamobile.com\/tin-tuc\/","logo":{"@type":"ImageObject","inLanguage":"vi","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/logo\/image\/","url":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2021\/12\/logo-text.png","contentUrl":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2021\/12\/logo-text.png","width":256,"height":37,"caption":"Tin t\u1ee9c c\u00f4ng ngh\u1ec7 - HoangHaMobile"},"image":{"@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/hoanghamobilecom"]},{"@type":"Person","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/person\/bd62b9b9f8624b34df49eb671db6853a","name":"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean","image":{"@type":"ImageObject","inLanguage":"vi","@id":"https:\/\/hoanghamobile.com\/tin-tuc\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/74bcebffab89aeb362901537cb11326b?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/74bcebffab89aeb362901537cb11326b?s=96&d=mm&r=g","caption":"Nguy\u1ec5n Th\u1ecb M\u1ef9 Li\u00ean"},"url":"https:\/\/hoanghamobile.com\/tin-tuc\/author\/nguyen-thi-my-lien\/"}]}},"_links":{"self":[{"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/posts\/300308","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/users\/97"}],"replies":[{"embeddable":true,"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/comments?post=300308"}],"version-history":[{"count":0,"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/posts\/300308\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/media\/300310"}],"wp:attachment":[{"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/media?parent=300308"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/categories?post=300308"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hoanghamobile.com\/tin-tuc\/wp-json\/wp\/v2\/tags?post=300308"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}