{"common":{"save":0,"post_id":"6461","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6892","mon_id":"1158767","chapter_id":"1158801","post_id":"6461","question":"<p>Cho tam th\u1ee9c <span class=\"math-tex\">$f(x)=ax^2+bx+c\\space\\space(a\\ne0),\\space\\Delta=b^2-4ac$<\/span>. Ta c&oacute; <span class=\"math-tex\">$f(x)\\ge0,\\space\\forall x\\in\\mathbb{R}$<\/span>&nbsp;khi v&agrave; ch\u1ec9 khi:<\/p>","options":["<strong>A. <span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\le0 \\end{cases}$<\/span><\/strong>","<strong>B. <span class=\"math-tex\">$\\begin{cases}a\\le0\\\\\\Delta&lt;0 \\end{cases}$<\/span><\/strong>","<strong>C. <span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\ge0 \\end{cases}$<\/span><\/strong>","<strong>D. <span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta\\le0 \\end{cases}$<\/span><\/strong>"],"correct":"4","level":"1","hint":"","answer":"<p>&Aacute;p d\u1ee5ng \u0111\u1ecbnh l&yacute; v\u1ec1 d\u1ea5u c\u1ee7a tam th\u1ee9c b\u1eadc hai ta c&oacute;:&nbsp;<\/p><p><span class=\"math-tex\">$f(x)\\ge0,\\space\\forall x\\in\\mathbb{R}$<\/span>&nbsp;khi v&agrave; ch\u1ec9 khi&nbsp;<strong><span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta\\le0 \\end{cases}$<\/span>.<\/strong><\/p><p>Ch\u1ecdn<strong>&nbsp;<span style=\"color:#16a085;\">D.&nbsp;<span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta\\le0 \\end{cases}$<\/span><\/span><\/strong><span style=\"color:#16a085;\"><strong>A.&nbsp;<span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\le0 \\end{cases}$<\/span>B.&nbsp;<span class=\"math-tex\">$\\begin{cases}a\\le0\\\\\\Delta&lt;0 \\end{cases}$<\/span>C.&nbsp;<span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\ge0 \\end{cases}$<\/span><\/strong><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-05-30 05:38:29","option_type":"math","len":0},{"id":"6893","mon_id":"1158767","chapter_id":"1158801","post_id":"6461","question":"<p>Cho tam th\u1ee9c <span class=\"math-tex\">$f(x)=ax^2+bx+c\\space\\space(a\\ne0),\\space\\Delta=b^2-4ac$<\/span>. Ta c&oacute; <span class=\"math-tex\">$f(x)&gt;0,\\space\\forall x\\in\\mathbb{R}$<\/span>&nbsp;khi v&agrave; ch\u1ec9 khi:<\/p>","options":["<strong>A. <span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\le0 \\end{cases}$<\/span><\/strong>","<strong><span aria-label=\"math widget\" contenteditable=\"false\" role=\"region\" tabindex=\"-1\"><\/span>B. <span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta&lt;0 \\end{cases}$<\/span><\/strong>","<strong>C. <span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\ge0 \\end{cases}$<\/span><\/strong>","<strong>D. <span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta\\le0 \\end{cases}$<\/span><\/strong>"],"correct":"2","level":"1","hint":"","answer":"<p>&Aacute;p d\u1ee5ng \u0111\u1ecbnh l&yacute; v\u1ec1 d\u1ea5u c\u1ee7a tam th\u1ee9c b\u1eadc hai ta c&oacute;:&nbsp;<\/p><p><span class=\"math-tex\">$f(x)&gt;0,\\space\\forall x\\in\\mathbb{R}$<\/span>&nbsp;khi v&agrave; ch\u1ec9 khi&nbsp;<strong><span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta<0 \\end{cases}$<\/span>.<\/strong><\/p><p>Ch\u1ecdn<strong>&nbsp;<span style=\"color:#16a085;\">B.&nbsp;<span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta&lt;0 \\end{cases}$<\/span><\/span><\/strong><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-05-30 05:39:11","option_type":"math","len":0},{"id":"6895","mon_id":"1158767","chapter_id":"1158801","post_id":"6461","question":"<p>Cho tam th\u1ee9c <span class=\"math-tex\">$f(x)=ax^2+bx+c\\space\\space(a\\ne0),\\space\\Delta=b^2-4ac$<\/span>. Ta c&oacute; <span class=\"math-tex\">$f(x)<0,\\space\\forall x\\in\\mathbb{R}$<\/span>&nbsp;khi v&agrave; ch\u1ec9 khi:<\/p>","options":["<strong>A. <span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\le0 \\end{cases}$<\/span> <\/strong>\u200b\u200b\u200b\u200b\u200b\u200b\u200b","<strong>B. <span class=\"math-tex\">$\\begin{cases}a<0\\\\\\Delta<0 \\end{cases}$<\/span><\/strong>","<strong>C. <span class=\"math-tex\">$\\begin{cases}a&lt;0\\\\\\Delta\\ge0 \\end{cases}$<\/span><\/strong>","<strong>D. <span class=\"math-tex\">$\\begin{cases}a&gt;0\\\\\\Delta\\le0 \\end{cases}$<\/span><\/strong>"],"correct":"2","level":"1","hint":"","answer":"<p>&Aacute;p d\u1ee5ng \u0111\u1ecbnh l&yacute; v\u1ec1 d\u1ea5u c\u1ee7a tam th\u1ee9c b\u1eadc hai ta c&oacute;:&nbsp;<\/p><p><span class=\"math-tex\">$f(x)<0,\\space\\forall x\\in\\mathbb{R}$<\/span>&nbsp;khi v&agrave; ch\u1ec9 khi&nbsp;<strong><span class=\"math-tex\">$\\begin{cases}a<0\\\\\\Delta<0 \\end{cases}$<\/span>.<\/strong><\/p><p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.&nbsp;<span class=\"math-tex\">$\\begin{cases}a<0\\\\\\Delta<0 \\end{cases}$<\/span><\/strong><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-05-30 05:44:40","option_type":"math","len":0}]}