Toán lớp 11 - Đề kiểm tra 45 phút - Toán lớp 11 - Tháng 10 - Số 1

{"save":1,"level":1,"time":"45","total":20,"point":5,"segment":[{"id":"128","test_id":"205","question":"<p>T&igrave;m nghi\u1ec7m d\u01b0\u01a1ng nh\u1ecf nh\u1ea5t c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$2\\sin \\left( {4x - \\dfrac{\\pi }{3}} \\right) - 1 = 0$<\/span><\/p>","options":["A.&nbsp;<span class=\"math-tex\">$x = \\dfrac{\\pi }{4}.$<\/span>","B.&nbsp;<span class=\"math-tex\">$x = \\dfrac{7\\pi }{24}.$<\/span>","C.&nbsp;<span class=\"math-tex\">$x = \\dfrac{\\pi }{8}.$<\/span>","D.&nbsp;<span class=\"math-tex\">$x = \\dfrac{\\pi }{12}.$<\/span>"],"correct":"3","answer":"<p>Ta c&oacute;&nbsp;<span class=\"math-tex\">$2\\sin \\left( {4x - \\dfrac{\\pi }{3}} \\right) - 1 = 0$<\/span><span class=\"math-tex\">$ \\Leftrightarrow \\sin \\left( {4x - \\dfrac{\\pi }{3}} \\right) = \\dfrac{1}{2}$<\/span><span class=\"math-tex\">$ \\Leftrightarrow \\sin \\left( {4x - \\dfrac{\\pi }{3}} \\right) = \\sin \\dfrac{\\pi }{6}$<\/span><\/p><p><span class=\"math-tex\">$ \\Leftrightarrow \\left[ \\begin{array}{l}\\n4x - \\dfrac{\\pi }{3} = \\dfrac{\\pi }{6} + k2\\pi \\\\\\n4x - \\dfrac{\\pi }{3} = \\pi - \\dfrac{\\pi }{6} + k2\\pi \\n\\end{array} \\right.$<\/span><span class=\"math-tex\">$ \\Leftrightarrow \\left[ \\begin{array}{l}\\nx = \\dfrac{\\pi }{8} + \\dfrac{{k\\pi }}{2}\\\\\\nx = \\dfrac{{7\\pi }}{{24}} + \\dfrac{{k\\pi }}{2}\\n\\end{array} \\right.{\\rm{ }}\\left( {k \\in \\mathbb{Z} } \\right).$<\/span><\/p><p>V\u1eady&nbsp;<span class=\"math-tex\">$x = \\dfrac{\\pi }{8}.$<\/span>&nbsp;l&agrave; nghi\u1ec7m d\u01b0\u01a1ng nh\u1ecf nh\u1ea5t<\/p><p>\u0110&aacute;p &aacute;n C<\/p>","type":"choose","user_id":"88","test":"0","date":"2020-03-11 18:12:06"},{"id":"129","test_id":"205","question":"<p>Trong c&aacute;c ph\u01b0\u01a1ng tr&igrave;nh sau, ph\u01b0\u01a1ng tr&igrave;nh n&agrave;o t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$2{\\cos ^2}x = 1$<\/span><\/p>","options":["A.&nbsp;<span class=\"math-tex\">$\\sin x = \\dfrac{{\\sqrt 2 }}{2}.$<\/span>","B.&nbsp;<span class=\"math-tex\">$2\\sin x + \\sqrt 2 = 0.$<\/span>","C.&nbsp;<span class=\"math-tex\">$\\tan x=1$<\/span>","D.&nbsp;<span class=\"math-tex\">$\\tan ^2 x=1$<\/span>"],"correct":"4","answer":"<p>Ta c&oacute;&nbsp;<span class=\"math-tex\">$2{\\cos ^2}x = 1$<\/span><span class=\"math-tex\">$\\Leftrightarrow {\\cos ^2}x = \\dfrac{1}{2}$<\/span>&nbsp;M&agrave;&nbsp;<span class=\"math-tex\">${\\sin ^2}x + {\\cos ^2}x = 1 \\Rightarrow {\\sin ^2}x = \\dfrac{1}{2}.$<\/span><\/p><p>Do \u0111&oacute;&nbsp;<span class=\"math-tex\">${\\tan ^2}x = \\dfrac{{{{\\sin }^2}x}}{{{{\\cos }^2}x}} = 1$<\/span><\/p><p>\u0110&aacute;p &aacute;n D<\/p>","type":"choose","user_id":"88","test":"0","date":"2020-03-11 18:15:36"}]}