\u0110\u1ec1 thi gi\u1eefa h\u1ecdc k\u00ec 2 l\u1edbp 11 m\u00f4n To\u00e1n n\u0103m 2015 \u2013 THPT Tri\u1ec7u S\u01a1n c\u00f3 \u0111\u00e1p \u00e1n chi ti\u1ebft, c\u00e1c em tham kh\u1ea3o d\u01b0\u1edbi \u0111\u00e2y:<\/p>\n
I. PH\u1ea6N CHUNG <\/strong>(9,0 \u0111i\u1ec3m)<\/em><\/strong><\/p>\n B\u00e0i 1.<\/strong> (2.0 \u0111i\u1ec3m)<\/em>. T\u00ecm c\u00e1c gi\u1edbi h\u1ea1n c\u1ee7a d\u00e3y s\u1ed1 sau<\/p>\n <\/p>\n \u00a0<\/strong><\/p>\n B\u00e0i 2.<\/strong> (2.0 \u0111i\u1ec3m) <\/em>T\u00ecm c\u00e1c gi\u1edbi h\u1ea1n c\u1ee7a h\u00e0m s\u1ed1 sau<\/p>\n \u00a0<\/strong><\/p>\n B\u00e0i 3.<\/strong> (2,0 \u0111i\u1ec3m). <\/em>\u00a0T\u00ecm s\u1ed1 h\u1ea1ng \u0111\u1ea7u v\u00e0 c\u00f4ng sai c\u1ee7a m\u1ed9t c\u1ea5p s\u1ed1 c\u1ed9ng, bi\u1ebft c\u00e1c s\u1ed1 h\u1ea1ng c\u1ee7a n\u00f3 th\u1ecfa m\u00e3n .<\/p>\n <\/p>\n B\u00e0i 4.<\/strong> (3,0 \u0111i\u1ec3m).\u00a0<\/em><\/p>\n Cho t\u1ee9 di\u1ec7n ABCD c\u00f3 AB, AC, AD \u0111\u00f4i m\u1ed9t vu\u00f4ng g\u00f3c v\u1edbi nhau. \u00a0 G\u1ecdi H l\u00e0 h\u00ecnh chi\u1ebfu c\u1ee7a A tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng CD.<\/p>\n a) Ch\u1ee9ng minh AB vu\u00f4ng g\u00f3c v\u1edbi CD;<\/p>\n b) G\u1ecdi K l\u00e0 ch\u00e2n \u0111\u01b0\u1eddng cao v\u1ebd t\u1eeb A c\u1ee7a tam gi\u00e1c ABH. Ch\u1ee9ng minh r\u1eb1ng AK vu\u00f4ng g\u00f3c v\u1edbi (BCD);<\/p>\n c) Gi\u1ea3 s\u1eed HC = 3HD, KB = 4KH. H\u00e3y bi\u1ec3u di\u1ec5n vect\u01a1 AK \u00a0theo c\u00e1c vect\u01a1 AB, AC, Ad \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0.<\/p>\n \u00a0<\/strong>II. PH\u1ea6N RI\u00caNG <\/strong>(1,0 \u0111i\u1ec3m). H\u1ecdc sinh \u0111\u01b0\u1ee3c ch\u1ecdn m\u1ed9t trong hai b\u00e0i<\/em><\/strong> B\u00e0i 5A\u00a0ho\u1eb7c<\/em> B\u00e0i 5B<\/strong>.<\/em><\/strong><\/p>\n B\u00e0i 5A.<\/strong> (1,0 \u0111i\u1ec3m). <\/em>Cho ba s\u1ed1 a, b, c tho\u1ea3 m\u00e3n h\u1ec7 th\u1ee9c 2a + 3b + 6c = 0. Ch\u1ee9ng minh r\u1eb1ng ph\u01b0\u01a1ng \u00a0tr\u00ecnh ax2<\/sup> + bx + c = 0 \u00a0c\u00f3 \u00edt nh\u1ea5t m\u1ed9t nghi\u1ec7m thu\u1ed9c kho\u1ea3ng (0; 1).\u00a0<\/strong><\/p>\n B\u00e0i 5B.<\/strong> (1,0 \u0111i\u1ec3m). <\/em>\u00a0Ch\u1ee9ng minh ph\u01b0\u01a1ng tr\u00ecnh 8x3<\/sup> \u2013 6x -1 = 0 c\u00f3 3 nghi\u1ec7m ph\u00e2n bi\u1ec7t. T\u00ecm 3 nghi\u1ec7m \u0111\u00f3.<\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" \u0110\u1ec1 thi gi\u1eefa h\u1ecdc k\u00ec 2 l\u1edbp 11 m\u00f4n To\u00e1n n\u0103m 2015 \u2013 THPT Tri\u1ec7u S\u01a1n c\u00f3 \u0111\u00e1p \u00e1n chi ti\u1ebft, c\u00e1c em tham kh\u1ea3o d\u01b0\u1edbi \u0111\u00e2y: \u0110\u1ec1 thi gi\u1eefa h\u1ecdc k\u00ec 2 l\u1edbp 11 m\u00f4n To\u00e1n n\u0103m 2015 \u2013 THPT Tri\u1ec7u S\u01a1n I. PH\u1ea6N CHUNG (9,0 \u0111i\u1ec3m) B\u00e0i 1. (2.0 \u0111i\u1ec3m). T\u00ecm c\u00e1c gi\u1edbi […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[171],"tags":[],"yoast_head":"\n\u0110\u00e1p \u00e1n \u0111\u1ec1 thi gi\u1eefa h\u1ecdc k\u00ec 2 l\u1edbp 11 m\u00f4n To\u00e1n n\u0103m 2015 \u2013 THPT Tri\u1ec7u S\u01a1n<\/strong><\/h4>\n