{"common":{"save":0,"post_id":"8000","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8636","post_id":"8000","mon_id":"1159278","chapter_id":"1159330","question":"<p>Cho hàm s\u1ed1 y = 2x² có \u0111\u1ed3 th\u1ecb là (P), các \u0111i\u1ec3m thu\u1ed9c (P) có tung \u0111\u1ed9 b\u1eb1ng 4 là:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$(\\sqrt{2};4),(-\\sqrt{2};4)$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$(2;4),(-2;4)$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$(4;4),(-4;4)$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$(1;4),(-1;4)$<\/span>"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$(\\sqrt{2};4),(-\\sqrt{2};4)$<\/span>.<\/span><\/p><p>Thay y = 4 ta \u0111\u01b0\u1ee3c <span class=\"math-tex\">$4=2x^2$<\/span> suy ra <span class=\"math-tex\">$x=\\pm\\sqrt{2}$<\/span>.<\/p><p>V\u1eady các \u0111i\u1ec3m th\u1ecfa mãn bài toán là <span class=\"math-tex\">$(\\sqrt{2};4),(-\\sqrt{2};4)$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 09:46:49","option_type":"math","len":0},{"id":"8639","post_id":"8000","mon_id":"1159278","chapter_id":"1159330","question":"<p>Cho hàm s\u1ed1 <span class=\"math-tex\">$y=f(x)=-2x^2$<\/span>. Bi\u1ebft <span class=\"math-tex\">$f(a)=-10+4\\sqrt{6}$<\/span>, giá tr\u1ecb c\u1ee7a a là:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\pm(\\sqrt{3}-\\sqrt{2})$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\pm(\\sqrt{3}+\\sqrt{2})$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\pm\\sqrt{3}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\pm\\sqrt{2}$<\/span>"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$\\pm(\\sqrt{3}-\\sqrt{2})$<\/span>.<\/span><\/p><p>Vì <span class=\"math-tex\">$f(a)=-10+4\\sqrt{6}$<\/span> nên <span class=\"math-tex\">$-2a^2=-2(5-2\\sqrt{6})$<\/span>.<\/p><p>Suy ra <span class=\"math-tex\">$a^2=(\\sqrt{3}-\\sqrt{2})^2$<\/span>.<\/p><p>Hay a = <span style=\"color:#16a085;\"><span class=\"math-tex\">$\\pm(\\sqrt{3}-\\sqrt{2})$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 09:55:34","option_type":"math","len":0},{"id":"8640","post_id":"8000","mon_id":"1159278","chapter_id":"1159330","question":"<p>Cho hàm s\u1ed1 <span class=\"math-tex\">$y=ax^2$<\/span> (a <span class=\"math-tex\">$\\ne$<\/span> 0) có \u0111\u1ed3 th\u1ecb là Parabol (P). Xác \u0111\u1ecbnh a \u0111\u1ec3 (P) \u0111i qua \u0111i\u1ec3m <span class=\"math-tex\">$A(-\\sqrt{2};4)$<\/span>?<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$a=-\\sqrt{2}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$a=\\sqrt{2}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$a=-2$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$a=2$<\/span>"],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> <span class=\"math-tex\">$a=2$<\/span>.<\/span><\/p><p>Thay <span class=\"math-tex\">$x=-\\sqrt{2};y=4$<\/span> ta \u0111\u01b0\u1ee3c <span class=\"math-tex\">$a.2=4$<\/span> suy ra a = 2.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 09:59:13","option_type":"math","len":0}]}
