{"common":{"save":0,"post_id":"8734","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6302","post_id":"8734","mon_id":"1159285","chapter_id":"1159382","question":"<p>Trong không gian Oxyz, cho hai \u0111i\u1ec3m M(3;–2;1) và N(1;2;3). Ph\u01b0\u01a1ng trình \u0111\u01b0\u1eddng th\u1eb3ng MN là<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=1+t\\\\y=-2+2t\\\\z=-1+3t\\end{cases},t\\in\\mathbb{R}$<\/span>.","<strong>B.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=1+t\\\\y=2-2t\\\\z=3-t\\end{cases},t\\in\\mathbb{R}$<\/span>.","<strong>C.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=-1+t\\\\y=-2-2t\\\\z=-3-3t\\end{cases},t\\in\\mathbb{R}$<\/span>.","<strong>D.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=1+t\\\\y=2\\\\z=3+t\\end{cases},t\\in\\mathbb{R}$<\/span>."],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=1+t\\\\y=2-2t\\\\z=3-t\\end{cases},t\\in\\mathbb{R}$<\/span>.<\/span><\/p><p>Ta có: <span class=\"math-tex\">$\\overrightarrow{MN}=(-2;4;2)$<\/span>.<\/p><p>\u0110\u01b0\u1eddng th\u1eb3ng MN \u0111i qua N(1; 2; 3) và có 1 vector ch\u1ec9 ph\u01b0\u01a1ng là <span class=\"math-tex\">$\\overrightarrow{u}=-\\dfrac{1}{2}\\overrightarrow{MN}=(1;-2;-1)$<\/span> nên có ph\u01b0\u01a1ng trình là:<\/p><p><span class=\"math-tex\">$\\begin{cases}x=1+t\\\\y=2-2t\\\\z=3-t\\end{cases},t\\in\\mathbb{R}$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-03 09:16:49","option_type":"math","len":0},{"id":"6303","post_id":"8734","mon_id":"1159285","chapter_id":"1159382","question":"<p>Trong không gian Oxyz , ph\u01b0\u01a1ng trình tham s\u1ed1 c\u1ee7a \u0111\u01b0\u1eddng th\u1eb3ng d \u0111i qua A(3;–2;1) và vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng <span class=\"math-tex\">$(P):-x+2y-2z+1=0$<\/span> là:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=3-t\\\\y=-2+2t\\\\z=1-2t\\end{cases},t\\in\\mathbb{R}$<\/span>.","<strong>B.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=1+3t\\\\y=-2-2t\\\\z=2-t\\end{cases},t\\in\\mathbb{R}$<\/span>.","<strong>C.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=-3-t\\\\y=2+2t\\\\z=-1-2t\\end{cases},t\\in\\mathbb{R}$<\/span>.","<strong>D.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=3-t\\\\y=2-2t\\\\z=1-2t\\end{cases},t\\in\\mathbb{R}$<\/span>."],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$\\begin{cases}x=3-t\\\\y=-2+2t\\\\z=1-2t\\end{cases},t\\in\\mathbb{R}$<\/span>.<\/span><\/p><p><span style=\"color:#16a085;\"><\/span>Vì d vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng <span class=\"math-tex\">$(P):-x+2y-2z+1=0$<\/span> nên d có m\u1ed9t vect\u01a1 ch\u1ec9 ph\u01b0\u01a1ng là <span class=\"math-tex\">$\\overrightarrow{u}=(-1;2;-2)$<\/span>.<\/p><p>Ph\u01b0\u01a1ng trình tham s\u1ed1 c\u1ee7a \u0111\u01b0\u1eddng th\u1eb3ng d \u0111i qua A(3; –2; 1) và vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng <span class=\"math-tex\">$(P):-x+2y-2z+1=0$<\/span> là: <span class=\"math-tex\">$\\begin{cases}x=3-t\\\\y=-2+2t\\\\z=1-2t\\end{cases},t\\in\\mathbb{R}$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-03 09:19:57","option_type":"math","len":0},{"id":"6306","post_id":"8734","mon_id":"1159285","chapter_id":"1159382","question":"<p>Trong không gian Oxyz, \u0111\u01b0\u1eddng th\u1eb3ng d \u0111i qua \u0111i\u1ec3m A(1;4;–7) và vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng <span class=\"math-tex\">$(P):x+2y-2z+2025=0$<\/span> có ph\u01b0\u01a1ng trình là<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{x-1}{1}=\\dfrac{y-4}{-2}=\\dfrac{z+7}{-2}$<\/span>.","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{x-1}{1}=\\dfrac{y-4}{2}=\\dfrac{z-7}{-2}$<\/span>.","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{x-1}{1}=\\dfrac{y-4}{2}=\\dfrac{z+7}{-2}$<\/span>.","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{x-1}{1}=\\dfrac{y+4}{4}=\\dfrac{z-7}{-7}$<\/span>."],"correct":"3","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{x-1}{1}=\\dfrac{y-4}{2}=\\dfrac{z+7}{-2}$<\/span>.<\/span><\/p><p>Vì d vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng <span class=\"math-tex\">$(P):x+2y-2z+2025=0$<\/span> nên d có m\u1ed9t vect\u01a1 ch\u1ec9 ph\u01b0\u01a1ng là <span class=\"math-tex\">$\\overrightarrow{u}=(1;2;-2)$<\/span>.<\/p><p>Ph\u01b0\u01a1ng trình c\u1ee7a \u0111\u01b0\u1eddng th\u1eb3ng d \u0111i qua A(1; 4; –7) và vuông góc v\u1edbi m\u1eb7t ph\u1eb3ng <span class=\"math-tex\">$(P):x+2y-2z+2025=0$<\/span> là: <span class=\"math-tex\">$\\dfrac{x-1}{1}=\\dfrac{y-4}{2}=\\dfrac{z+7}{-2}$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-03 09:30:40","option_type":"math","len":0}]}