{"common":{"save":0,"post_id":"7865","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8010","post_id":"7865","mon_id":"1159278","chapter_id":"1159328","question":"<p>Cho tam giác ABC vuông t\u1ea1i A . Bi\u1ebft <span class=\"math-tex\">$AB=3$<\/span> cm, <span class=\"math-tex\">$BC=5$<\/span> cm, sin B b\u1eb1ng:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{4}{5}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{5}{4}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{5}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{4}$<\/span>"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{4}{5}$<\/span>.<\/span><\/p><p>Tam giác ABC vuông t\u1ea1i A, áp d\u1ee5ng \u0111\u1ecbnh lí Pythagore, ta có:<\/p><p>BC² = AB² + AC²<\/p><p>AC² = BC² – AB² = 5² – 3² = 16<\/p><p>AC = 4 cm<\/p><p>Suy ra <span class=\"math-tex\">$\\sin B=\\dfrac{AC}{BC}=\\dfrac{4}{5}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-21 02:32:06","option_type":"math","len":0},{"id":"8011","post_id":"7865","mon_id":"1159278","chapter_id":"1159328","question":"<p>Cho tam giác ABC vuông t\u1ea1i A . Bi\u1ebft <span class=\"math-tex\">$AB=3$<\/span> cm, <span class=\"math-tex\">$BC=5$<\/span> cm, tan C b\u1eb1ng:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{5}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{4}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{4}{5}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{4}{3}$<\/span>"],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{4}$<\/span>.<\/span><\/p><p>Tam giác ABC vuông t\u1ea1i A, áp d\u1ee5ng \u0111\u1ecbnh lí Pythagore, ta có:<\/p><p>BC² = AB² + AC²<\/p><p>AC² = BC² – AB² = 5² – 3² = 16<\/p><p>AC = 4 cm<\/p><p>Suy ra <span class=\"math-tex\">$\\tan C=\\dfrac{AB}{AC}=\\dfrac{3}{4}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-21 02:35:42","option_type":"math","len":0},{"id":"8013","post_id":"7865","mon_id":"1159278","chapter_id":"1159328","question":"<p>Ta có sin 74° = cos <input class=\"tim_x input_number\" tpl=\"dien_so\" type=\"text\"\/>°.<\/p>","options":"","correct":["[\"16\"]"],"level":"2","hint":"","answer":"<p>S\u1ed1 c\u1ea7n \u0111i\u1ec1n là <span style=\"color:#16a085;\"><strong>1<\/strong><\/span><span style=\"color:#16a085;\"><strong>6<\/strong><\/span>.<\/p><p>N\u1ebfu hai góc ph\u1ee5 nhau thì sin góc này b\u1eb1ng cos góc kia nên sin 74° = cos 16°.<\/p><p>(74° + 16° = 90°)<\/p>","type":"blank","extra_type":"","time":"0","user_id":"127","test":"0","date":"2024-10-21 02:40:37"}]}