B\u00e0i 1 (trang 75 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\nTrong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau, kh\u1eb3ng \u0111\u1ecbnh n\u00e0o \u0111\u00fang kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sai?<\/p>\n
a) V\u1edbi s\u1ed1 th\u1ef1c a v\u00e0 s\u1ed1 nguy\u00ean m, n, ta c\u00f3:<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/1-467.png\")
<\/p>\n
b) V\u1edbi s\u1ed1 th\u1ef1c a, b c\u00f9ng kh\u00e1c 0 v\u00e0 s\u1ed1 nguy\u00ean n, ta c\u00f3:<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/2-310.png\")
<\/p>\n
c) V\u1edbi s\u1ed1 th\u1ef1c a, b th\u1ecfa m\u00e3n 0 < a < b v\u1edbi s\u1ed1 nguy\u00ean a, ta c\u00f3 am<\/sup>\u00a0< bn<\/sup><\/p>\nd) V\u1edbi s\u1ed1 th\u1ef1c a \u2260 0 v\u00e0 hai s\u1ed1 nguy\u00ean m, n. ta c\u00f3: N\u1ebfu m > n th\u00ec am<\/sup>\u00a0> an<\/sup><\/p>\nL\u1eddi gi\u1ea3i:<\/b><\/p>\n
a) Sai:<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/3-158.png\")
<\/p>\n
b) \u0110\u00fang<\/p>\n
c) Sai. Ch\u1eb3ng h\u1ea1n: a0<\/sup>=b0<\/sup><\/p>\nd) Sai. Ch\u1eb3ng h\u1ea1n (\u22121)3<\/sup>\u00a0< (\u22121)2<\/sup><\/p>\n\n
\n
B\u00e0i 2 (trang 75 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\nX\u00e9t kh\u1eb3ng \u0111\u1ecbnh: \u201cV\u1edbi s\u1ed1 th\u1ef1c a v\u00e0 hai s\u1ed1 h\u1eefu t\u1ec9 r, s, ta c\u00f3 (ar<\/sup>\u00a0)s<\/sup>=ars<\/sup>. V\u1edbi \u0111i\u1ec1u ki\u1ec7n n\u00e0o trong c\u00e1c \u0111i\u1ec1u ki\u1ec7n sau th\u00ec kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 \u0111\u00fang:<\/p>\nA. A b\u1ea5t k\u00ec \u00a0\u00a0\u00a0 B. a \u2260 0 \u00a0\u00a0\u00a0 C. a > 0 \u00a0\u00a0\u00a0D. a < 0<\/p>\n
L\u1eddi gi\u1ea3i:<\/b><\/p>\n
B\u00e0i 3 (trang 76 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\nVi\u1ebft c\u00e1c d\u1ea1ng s\u1ed1 sau d\u01b0\u1edbi d\u1ea1ng s\u1ed1 nguy\u00ean hay ph\u00e2n ph\u1ed1 t\u1ed1i gi\u1ea3i:<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/1-468.png\")
<\/p>\n
L\u1eddi gi\u1ea3i:<\/b><\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/2-311.png\")
<\/p>\n
B\u00e0i 4 (trang 76 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\nTh\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh:<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/1-469.png\")
<\/p>\n
L\u1eddi gi\u1ea3i:<\/b><\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/2-312.png\")
<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/3-159.png\")
<\/p>\n
B\u00e0i 5 (trang 76 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b><\/span><\/p>\n\u0110\u01a1n gi\u1ea3n bi\u1ec3u th\u1ee9c<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/1-470.png\")
<\/p>\n
L\u1eddi gi\u1ea3i:<\/b><\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/2-313.png\")
<\/p>\n
B\u00e0i 6 (trang 76 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\nSo s\u00e1nh c\u00e1c s\u1ed1:<\/p>\n
a) \u221a2 v\u00e0 \u221b3<\/p>\n
b) \u221a3+\u221b30 v\u00e0 \u221b63<\/p>\n
c) \u221b7+\u221a15 v\u00e0 \u221a10-\u221b28<\/p>\n
L\u1eddi gi\u1ea3i:<\/b><\/p>\n
a) Gi\u1ea3 s\u1eed \u221a2 < \u221b3 <=> (\u221a2)2<\/sup>\u00a0< 3 <=> 2 \u221a2 < 3 <=> 8 < 9 \u0111\u00fang.<\/p>\nV\u1eady \u221a2 < \u221b3<\/p>\n
b) Gi\u1ea3 s\u1eed \u221a3+\u221b30 < \u221b63 <=> 3 \u221a3+9 \u221b30+3 \u221a3\u221b(302<\/sup>\u00a0)< 63-30<\/p>\n<=> 3 \u221a3+9\u221b3- +3 \u221a3 \u221b(302<\/sup>\u00a0) < 33 (*)<\/p>\nTa c\u00f3 3\u221b3 > 3<\/p>\n
9\u221b30 > 9\u221b27=27<\/p>\n
3 \u221a3 \u221b(302<\/sup>\u00a0) > 3 \u221b27.27=27 => \u221b3+9\u221b30+3 \u221a3 \u221b(302<\/sup>\u00a0) > 57 > 33<\/p>\nV\u1eady (*) sai => \u221a3+\u221b30 > \u221b63<\/p>\n
c) Gi\u1ea3 s\u1eed \u221b7+\u221a15 > \u221a10-\u221b28<=> \u221a15-\u221a10 > \u221b28-\u221b7<\/p>\n
<=> 5-2 \u221a150 > \u221b28-2\u221b28.7+\u221b(72<\/sup>\u00a0)<\/p>\n<=> 5+2\u221b28.7 > \u221b(282<\/sup>\u00a0)+2 \u221a155+\u221b(72<\/sup>\u00a0)<\/p>\nDo 2 \u221a155 > 2 \u221a125=2.5=10 > 5<\/p>\n
\u221b(282<\/sup>\u00a0)+2 \u221a155+\u221b(72<\/sup>\u00a0)=2+2\u221b(28.72<\/sup>.2) > 2\u221b28.7<\/p>\nV\u1eady 5+2\u221b28.7 < \u221b(282<\/sup>\u00a0)+2 \u221a155+\u221b(72<\/sup>\u00a0) => (*) sai. V\u1eady \u221b7+\u221a15 < \u221a10-\u221b28<\/p>\n\n
B\u00e0i 7 (trang 76 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\nCh\u1ee9ng minh<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/1-471.png\")
<\/p>\n
L\u1eddi gi\u1ea3i:<\/b><\/p>\n
Ta c\u00f3:<\/p>\n
![\"\"](\"https:\/\/lop12.edu.vn\/wp-content\/uploads\/2018\/03\/2-314.png\")
<\/div>\n
<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
B\u00e0i 1 (trang 75 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):\u00a0 Trong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau, kh\u1eb3ng \u0111\u1ecbnh n\u00e0o \u0111\u00fang kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sai? a) V\u1edbi s\u1ed1 th\u1ef1c a v\u00e0 s\u1ed1 nguy\u00ean m, n, ta c\u00f3: b) V\u1edbi s\u1ed1 th\u1ef1c a, b c\u00f9ng kh\u00e1c 0 v\u00e0 s\u1ed1 nguy\u00ean n, ta c\u00f3: c) V\u1edbi s\u1ed1 th\u1ef1c a, […]<\/p>\n","protected":false},"author":3,"featured_media":23564,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[1302],"tags":[1392,1393],"yoast_head":"\n
\u0110\u1ea1i s\u1ed1 - Ch\u01b0\u01a1ng 2 - B\u00e0i 1: L\u0169y th\u1eeba v\u1edbi s\u1ed1 m\u0169 h\u1eefu t\u1ec9<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/lop12.edu.vn\/dai-so-chuong-2-bai-1-luy-thua-voi-so-mu-huu-ti\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u0110\u1ea1i s\u1ed1 - Ch\u01b0\u01a1ng 2 - B\u00e0i 1: L\u0169y th\u1eeba v\u1edbi s\u1ed1 m\u0169 h\u1eefu t\u1ec9\" \/>\n<meta property=\"og:description\" content=\"B\u00e0i 1 (trang 75 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):\u00a0 Trong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau, kh\u1eb3ng \u0111\u1ecbnh n\u00e0o \u0111\u00fang kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sai? a) V\u1edbi s\u1ed1 th\u1ef1c a v\u00e0 s\u1ed1 nguy\u00ean m, n, ta c\u00f3: b) V\u1edbi s\u1ed1 th\u1ef1c a, b c\u00f9ng kh\u00e1c 0 v\u00e0 s\u1ed1 nguy\u00ean n, ta c\u00f3: c) V\u1edbi s\u1ed1 th\u1ef1c a, […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/lop12.edu.vn\/dai-so-chuong-2-bai-1-luy-thua-voi-so-mu-huu-ti\/\" \/>\n<meta property=\"og:site_name\" content=\"Lop12.edu.vn - 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