C\u00e2u 16:<\/b>\u00a0Cho hai vect\u01a1\u00a0a\u2192<\/i>,\u00a0b\u2192<\/i>\u00a0t\u1ea1o v\u1edbi nhau m\u1ed9t g\u00f3c 120o<\/sup>. Bi\u1ebft \u0111\u1ed9 d\u00e0i c\u1ee7a hai vect\u01a1 \u0111\u00f3 l\u1ea7n l\u01b0\u1ee3t l\u00e0 4 v\u00e0 3. \u0110\u1ed9 d\u00e0i c\u1ee7a vect\u01a1 t\u1ed5ng\u00a0a\u2192<\/i>\u00a0+\u00a0b\u2192<\/i>\u00a0l\u00e0:<\/p>\n A. 7\u00a0\u00a0\u00a0B. 1\u00a0\u00a0\u00a0C. \u221a13\u00a0\u00a0\u00a0D. \u221a37<\/p>\n C\u00e2u 17:<\/b>\u00a0Cho hai vect\u01a1\u00a0a\u2192<\/i>,\u00a0b\u2192<\/i>\u00a0t\u1ea1o v\u1edbi nhau m\u1ed9t g\u00f3c 60o<\/sup>\u00a0. Bi\u1ebft \u0111\u1ed9 d\u00e0i c\u1ee7a hai vect\u01a1 \u0111\u00f3 l\u1ea7n l\u01b0\u1ee3t l\u00e0 5 v\u00e0 10. \u0110\u1ed9 d\u00e0i c\u1ee7a vect\u01a1 hi\u1ec7u\u00a0a\u2192<\/i>\u00a0–\u00a0b\u2192<\/i>\u00a0l\u00e0:<\/p>\n A. 15\u00a0\u00a0\u00a0B. 5\u00a0\u00a0\u00a0C. 75\u00a0\u00a0\u00a0D. \u221a75<\/p>\n C\u00e2u 18:<\/b>\u00a0Trong kh\u00f4ng gian Oxyz, cho hai \u0111i\u1ec3m A(2;2;2), B(-4;-4;-4). \u0110i\u1ec3m n\u00e0o d\u01b0\u1edbi \u0111\u00e2y n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng AB?<\/p>\n A. M1<\/sub>(-1; 1; -1)\u00a0\u00a0\u00a0B. M2<\/sub>(1; -1; -1)\u00a0\u00a0\u00a0C. M3<\/sub>(-1; -1; 1)\u00a0\u00a0\u00a0D. M4<\/sub>(-1; -1; -1)<\/p>\n C\u00e2u 19:<\/b>\u00a0Trong kh\u00f4ng gian Oxyz, cho hai \u0111i\u1ec3m A(1;2;-3), B(3;6;-9). \u0110i\u1ec3m n\u00e0o d\u01b0\u1edbi \u0111\u00e2y kh\u00f4ng n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng AB?<\/p>\n A. M1<\/sub>(2; 4; -6)\u00a0\u00a0\u00a0B. M2<\/sub>(-1; -2; 3)\u00a0\u00a0\u00a0C. M3<\/sub>(0; 0; 1)\u00a0\u00a0\u00a0D. M4<\/sub>(5; 10; -15)<\/p>\n C\u00e2u 20:<\/b>\u00a0Trong kh\u00f4ng gian Oxyz, cho ba \u0111i\u1ec3m A(2;1;-3), B(4;2;-6), C(10;5;-15). Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sau \u0111\u00e2y l\u00e0 \u0111\u00fang?<\/p>\n <\/p>\n C\u00e2u 21:<\/b>\u00a0Trong kh\u00f4ng gian Oxyz, cho hai vect\u01a1\u00a0a\u2192<\/i>\u00a0= (1; -2; -3),\u00a0b\u2192<\/i>\u00a0= (m; 2m – 1; 1) . V\u1edbi nh\u1eefng gi\u00e1 tr\u1ecb n\u00e0o c\u1ee7a m th\u00ec hai vect\u01a1\u00a0a\u2192<\/i>\u00a0v\u00e0\u00a0b\u2192<\/i>\u00a0vu\u00f4ng g\u00f3c?<\/p>\n A. m = -1\/3\u00a0\u00a0\u00a0B. m = -1\/2 \u00a0\u00a0\u00a0C. m = 1\u00a0\u00a0\u00a0D. m = 0<\/p>\n C\u00e2u 22:<\/b>\u00a0Trong kh\u00f4ng gian Oxyz, cho hai vect\u01a1\u00a0a\u2192<\/i>\u00a0= (1; m; 2m – 1),\u00a0b\u2192<\/i>\u00a0= (m + 1; m2<\/sup>\u00a0+ 1; 4m – 2) . V\u1edbi nh\u1eefng gi\u00e1 tr\u1ecb n\u00e0o c\u1ee7a m th\u00ec cos(a\u2192<\/i>,\u00a0b\u2192<\/i>) \u0111\u1ea1t gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t?<\/p>\n A. m = 1\/2 \u00a0\u00a0\u00a0C. m = 1<\/p>\n B. m = 1 ho\u1eb7c m = 1\/2 \u00a0\u00a0\u00a0D. Kh\u00f4ng t\u1ed3n t\u1ea1i m th\u1ecfa m\u00e3n<\/p>\n H\u01b0\u1edbng d\u1eabn gi\u1ea3i v\u00e0 \u0110\u00e1p \u00e1n<\/b><\/p>\n C\u00e2u 22:<\/b><\/p>\n cos(a\u2192<\/i>,\u00a0b\u2192<\/i>)\u0111\u1ea1t gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t khi v\u00e0 ch\u1ec9 khi g\u00f3c gi\u1eefa hai vect\u01a1\u00a0a\u2192<\/i>\u00a0v\u00e0\u00a0b\u2192<\/i>\u00a0l\u00e0 0o<\/sup>, ngh\u0129a l\u00e0 t\u1ed3n t\u1ea1i m\u1ed9t s\u1ed1 d\u01b0\u01a1ng k sao cho\u00a0b\u2192<\/i>\u00a0= k.a\u2192<\/i><\/p>\n","protected":false},"excerpt":{"rendered":" C\u00e2u 16:\u00a0Cho hai vect\u01a1\u00a0a\u2192,\u00a0b\u2192\u00a0t\u1ea1o v\u1edbi nhau m\u1ed9t g\u00f3c 120o. Bi\u1ebft \u0111\u1ed9 d\u00e0i c\u1ee7a hai vect\u01a1 \u0111\u00f3 l\u1ea7n l\u01b0\u1ee3t l\u00e0 4 v\u00e0 3. \u0110\u1ed9 d\u00e0i c\u1ee7a vect\u01a1 t\u1ed5ng\u00a0a\u2192\u00a0+\u00a0b\u2192\u00a0l\u00e0: A. 7\u00a0\u00a0\u00a0B. 1\u00a0\u00a0\u00a0C. \u221a13\u00a0\u00a0\u00a0D. \u221a37 C\u00e2u 17:\u00a0Cho hai vect\u01a1\u00a0a\u2192,\u00a0b\u2192\u00a0t\u1ea1o v\u1edbi nhau m\u1ed9t g\u00f3c 60o\u00a0. Bi\u1ebft \u0111\u1ed9 d\u00e0i c\u1ee7a hai vect\u01a1 \u0111\u00f3 l\u1ea7n l\u01b0\u1ee3t l\u00e0 5 v\u00e0 10. \u0110\u1ed9 […]<\/p>\n","protected":false},"author":3,"featured_media":28229,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[157],"tags":[1450,1448],"yoast_head":"\n\n\n
\n 16-C<\/td>\n 17-D<\/td>\n 18-D<\/td>\n 19-C<\/td>\n 20-B<\/td>\n 21-A<\/td>\n 22-C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n