{"common":{"save":0,"post_id":"7112","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5899","post_id":"7112","mon_id":"1158924","chapter_id":"1159187","question":"<p>Vi\u1ebft ph\u01b0\u01a1ng trình ti\u1ebfp tuy\u1ebfn c\u1ee7a \u0111\u1ed3 th\u1ecb hàm s\u1ed1 <span class=\"math-tex\">$y=f(x)=x^3-3x$<\/span> t\u1ea1i \u0111i\u1ec3m có hoành \u0111\u1ed9 b\u1eb1ng 2.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$y=-9x+16$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$y=-9x+20$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$y=9x-20$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$y=9x-16$<\/span>"],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> <span class=\"math-tex\">$y=9x-16$<\/span>.<\/span><\/p><p>Ta có f(2) = 2.<\/p><p><span class=\"math-tex\">$f^\\prime(2)=\\displaystyle\\lim_{x\\to2}\\dfrac{f(x)-f(2)}{x-2}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to2}\\dfrac{x^3-3x-2}{x-2}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to2}\\dfrac{(x+1)^2(x-2)}{x-2}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to2}(x+1)^2$<\/span><\/p><p><span class=\"math-tex\">$=9$<\/span><\/p><p>V\u1eady ph\u01b0\u01a1ng trình ti\u1ebfp tuy\u1ebfn c\u1ee7a \u0111\u1ed3 th\u1ecb hàm s\u1ed1 t\u1ea1i \u0111i\u1ec3m có hoành \u0111\u1ed9 b\u1eb1ng 2 là<\/p><p><span class=\"math-tex\">$y=f^\\prime(2)(x-2)+f(x)$<\/span><\/p><p><span class=\"math-tex\">$y=9(x-2)+2$<\/span><\/p><p><span class=\"math-tex\">$y=9x-16$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-05-29 02:55:30","option_type":"math","len":0},{"id":"5900","post_id":"7112","mon_id":"1158924","chapter_id":"1159187","question":"<p>Ph\u01b0\u01a1ng trình ti\u1ebfp tuy\u1ebfn c\u1ee7a \u0111\u1ed3 th\u1ecb hàm s\u1ed1 <span class=\"math-tex\">$y=f(x)=3x-4x^2$<\/span> t\u1ea1i \u0111i\u1ec3m có hoành \u0111\u1ed9 b\u1eb1ng 0 là<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$y=0$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$y=3x$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$y=3x-2$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$y=-12x$<\/span>"],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> <span class=\"math-tex\">$y=3x$<\/span>.<\/span><\/p><p>Ta có <span class=\"math-tex\">$f(0)=0$<\/span><\/p><p><span class=\"math-tex\">$f^\\prime(0)=\\displaystyle\\lim_{x\\to0}\\dfrac{f(x)-f(0)}{x-0}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to0}\\dfrac{3x-4x^2}{x}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to0}\\dfrac{x(3-4x)}{x}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to0}(3-4x)$<\/span><\/p><p><span class=\"math-tex\">$=3$<\/span>.<\/p><p>V\u1eady ph\u01b0\u01a1ng trình ti\u1ebfp tuy\u1ebfn c\u1ea7n tìm là <span class=\"math-tex\">$y=f^\\prime(0)(x-0)+f(0)$<\/span> hay <span class=\"math-tex\">$y=3x$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-05-29 03:03:32","option_type":"math","len":0},{"id":"5903","post_id":"7112","mon_id":"1158924","chapter_id":"1159187","question":"<p>Hàm s\u1ed1 <span class=\"math-tex\">$y=f(x)=-x^3+3x-2$<\/span> có \u0111\u1ed3 th\u1ecb (C). Vi\u1ebft ph\u01b0\u01a1ng trình ti\u1ebfp tuy\u1ebfn c\u1ee7a (C) t\u1ea1i giao \u0111i\u1ec3m c\u1ee7a (C) v\u1edbi tr\u1ee5c tung.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$y=-2x+1$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$y=2x+1$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$y=3x-2$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$y=-3x-2$<\/span>"],"correct":"3","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> <span class=\"math-tex\">$y=3x-2$<\/span>.<\/span><\/p><p>Ta có giao \u0111i\u1ec3m c\u1ee7a (C) v\u1edbi tr\u1ee5c tung là \u0111i\u1ec3m (0 ; –2).<\/p><p>H\u1ec7 s\u1ed1 góc c\u1ee7a ti\u1ebfp tuy\u1ebfn là<\/p><p><span class=\"math-tex\">$f^\\prime(0)=\\displaystyle\\lim_{x\\to0}\\dfrac{f(x)-f(0)}{x-0}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to0}\\dfrac{-x^3+3x-2+2}{x}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to0}\\dfrac{x(-x^2+3)}{x}$<\/span><\/p><p><span class=\"math-tex\">$=\\displaystyle\\lim_{x\\to0}(-x^2+3)$<\/span><\/p><p><span class=\"math-tex\">$=3$<\/span><\/p><p>V\u1eady ti\u1ebfp tuy\u1ebfn c\u1ea7n tìm có ph\u01b0\u01a1ng trình là <span class=\"math-tex\">$y=f^\\prime(0)(x-0)-2$<\/span> hay <span class=\"math-tex\">$y=3x-2$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-05-29 03:14:21","option_type":"math","len":0}]}