{"common":{"save":0,"post_id":"6718","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7434","mon_id":"1158767","chapter_id":"1158801","post_id":"6718","question":"<p>Tr\u1ee5c \u0111\u1ed1i x\u1ee9ng c\u1ee7a parabol <span class=\"math-tex\">$y=-x^2+5x+3$<\/span> là \u0111\u01b0\u1eddng th\u1eb3ng có ph\u01b0\u01a1ng trình<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$x = \\dfrac{5}{4}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$x = -\\dfrac{5}{2}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$x=-\\dfrac{5}{4}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$x=\\dfrac{5}{2}$<\/span>"],"correct":"4","level":"2","hint":"","answer":"<p>Tr\u1ee5c \u0111\u1ed1i x\u1ee9ng c\u1ee7a parabol <span class=\"math-tex\">$y=ax^2+bx+c$<\/span> là \u0111\u01b0\u1eddng th\u1eb3ng <span class=\"math-tex\">$x=-\\dfrac{b}{2a}$<\/span> .<\/p><p>Tr\u1ee5c \u0111\u1ed1i x\u1ee9ng c\u1ee7a parabol <span class=\"math-tex\">$y=-x^2+5x+3$<\/span> là \u0111\u01b0\u1eddng th\u1eb3ng <span style=\"color:#16a085;\"><strong>D.<\/strong> <span class=\"math-tex\">$x=\\dfrac{5}{2}$<\/span> .<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-10-01 22:13:11","option_type":"math","len":0},{"id":"7437","mon_id":"1158767","chapter_id":"1158801","post_id":"6718","question":"<p>Cho hàm s\u1ed1 <span class=\"math-tex\">$y=x^2-2x+3$<\/span> . Ch\u1ecdn câu <strong>\u0111úng<\/strong>.<\/p>","options":["<strong>A.<\/strong> Hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(1;+\\infty)$<\/span>","<strong>B.<\/strong> Hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;1)$<\/span>","<strong>C.<\/strong> Hàm s\u1ed1 \u0111\u1ed3ng bi\u1ebfn trên <span class=\"math-tex\">$\\mathbb{R}$<\/span>","<strong>D.<\/strong> Hàm s\u1ed1 \u0111\u1ed3ng bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;1)$<\/span>"],"correct":"2","level":"2","hint":"","answer":"<p>Ta có <span class=\"math-tex\">$a=1>0$<\/span> , <span class=\"math-tex\">$b=-2$<\/span> , <span class=\"math-tex\">$c=3$<\/span> nên hàm s\u1ed1 có \u0111\u1ec9nh <span class=\"math-tex\">$I(1;2)$<\/span> .<\/p><p>T\u1eeb \u0111ó suy ra hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;1)$<\/span> và \u0111\u1ed3ng bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(1;+\\infty)$<\/span> .<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> Hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;1)$<\/span> .<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-10-01 22:18:20","option_type":"math","len":0},{"id":"7438","mon_id":"1158767","chapter_id":"1158801","post_id":"6718","question":"<p>Xét tính \u0111\u1ed3ng bi\u1ebfn, ngh\u1ecbch bi\u1ebfn c\u1ee7a hàm s\u1ed1 <span class=\"math-tex\">$y=x^2-4x+5$<\/span> trên các kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;2)$<\/span> và <span class=\"math-tex\">$(2;+\\infty)$<\/span> . Kh\u1eb3ng \u0111\u1ecbnh nào là <strong>\u0111úng<\/strong>?<\/p>","options":["<strong>A.<\/strong> Hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;2)$<\/span> và \u0111\u1ed3ng bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(2;+\\infty)$<\/span>.","<strong>B.<\/strong> Hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;2)$<\/span> và kho\u1ea3ng <span class=\"math-tex\">$(2;+\\infty)$<\/span>.","<strong>C.<\/strong> Hàm s\u1ed1 \u0111\u1ed3ng bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;2)$<\/span> và kho\u1ea3ng <span class=\"math-tex\">$(2;+\\infty)$<\/span>.","<strong>D.<\/strong> Hàm s\u1ed1 \u0111\u1ed3ng bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;2)$<\/span> và ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(2;+\\infty)$<\/span>."],"correct":"1","level":"2","hint":"","answer":"<p><span class=\"math-tex\">$y=x^2-4x+5$<\/span><\/p><p>T\u1eadp xác \u0111\u1ecbnh D = R.<\/p><p>T\u1ecda \u0111\u1ed9 \u0111\u1ec9nh <span class=\"math-tex\">$I(2;1)$<\/span> .<\/p><p>Do \u0111ó <span style=\"color:#16a085;\"><strong>A.<\/strong> Hàm s\u1ed1 ngh\u1ecbch bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(-\\infty;2)$<\/span> và \u0111\u1ed3ng bi\u1ebfn trên kho\u1ea3ng <span class=\"math-tex\">$(2;+\\infty)$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-10-01 22:23:26","option_type":"math","len":0}]}