{"save":1,"level":1,"time":"15","total":10,"point":5,"segment":[{"id":"48","test_id":"196","question":"<p>Cho&nbsp;<span class=\"math-tex\">$I=\\int_{1}^{2}{2x\\sqrt{{{x}^{2}}-1}dx}$<\/span><span><span><span>&nbsp;. Kh\u1eb3ng \u0111\u1ecbnh n&agrave;o sau \u0111&acirc;y sai?<\/span><\/span><\/span><\/p><p>&nbsp;<\/p>","options":["<span class=\"math-tex\">$I=\\dfrac{2}{3}\\sqrt{27}$<\/span>","<span class=\"math-tex\">$\\left. I=\\frac{2}{3}{{t}^{\\frac{3}{2}}} \\right|\\begin{matrix} 3 \\\\ 0 \\\\ \\end{matrix} $<\/span>","<span class=\"math-tex\">$I\\ge 3\\sqrt{3}$<\/span>","<span class=\"math-tex\">$I=\\int_{0}^{3}{\\sqrt{u}du} $<\/span>"],"correct":"3","answer":"<p>Ta c&oacute;:&nbsp;<span class=\"math-tex\">$I=\\int_{1}^{2}{2x\\sqrt{{{x}^{2}}-1}dx}$<\/span><\/p><p><span><span>\u0110\u1eb7t u =&nbsp;<span class=\"math-tex\">$x^2+1$<\/span><\/span><\/span><\/p><p><span class=\"math-tex\">$du=2xdx$<\/span><\/p><p><span><span>\u0110\u1ed5i c\u1eadn <\/span><\/span><span class=\"math-tex\">$t\u2208(0;3)$<\/span><\/p><p><span><span>Ta c&oacute;:&nbsp;<span class=\"math-tex\">$I=\u222b_0^3\\sqrt{u}du=\\frac{2}{3}\\sqrt{27}$<\/span><\/span><\/span><\/p><p>V\u1eady (C) sai.<\/p>","type":"choose","user_id":"108","test":"0","date":"2020-03-08 23:14:56"},{"id":"49","test_id":"196","question":"<p><span><span>T&igrave;m nguy&ecirc;n h&agrave;m c\u1ee7a&nbsp;<span class=\"math-tex\">$\\int{\\cos \\left( 2x-1 \\right)dx}$<\/span><\/span><\/span>&nbsp;.<span><span>Ch\u1ecdn \u0111&aacute;p &aacute;n \u0111&uacute;ng:<\/span><\/span><\/p>","options":["<span class=\"math-tex\">$\\frac{1}{2}sin\\left( 2x-1 \\right)+C$<\/span>","<span class=\"math-tex\">$sin\\left( 2x-1 \\right)+C$<\/span>","<span class=\"math-tex\">$2sin\\left( 2x-1 \\right)+C$<\/span>","<span class=\"math-tex\">$-\\frac{1}{2}sin\\left( 2x-1 \\right)+C$<\/span>"],"correct":"1","answer":"<p>&Aacute;p d\u1ee5ng c&ocirc;ng th\u1ee9c nguy&ecirc;n h&agrave;m m\u1edf r\u1ed9ng v\u1edbi h&agrave;m cos:<\/p><p>span class=\"math-tex\">$\u222bcos(2x-1)dx=\\frac{1}{2} sin(2x-1)+C$<\/span><\/p><p>&nbsp;<\/p>","type":"choose","user_id":"108","test":"0","date":"2020-03-08 23:26:16"}]}