{"common":{"save":0,"post_id":"7300","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7472","mon_id":"1158767","chapter_id":"1159257","post_id":"7300","question":"<p>Cho g&oacute;c&nbsp;<span class=\"math-tex\">$\\alpha \\in (90^o; 180^o)$<\/span>, kh\u1eb3ng \u0111\u1ecbnh n&agrave;o sau \u0111&acirc;y <strong>\u0111&uacute;ng<\/strong>?<\/p>","options":["<strong>A. <\/strong><span class=\"math-tex\">$\\sin\\alpha$<\/span> v&agrave; <span class=\"math-tex\">$\\cot\\alpha$<\/span> c&ugrave;ng d\u1ea5u","<strong>B. <\/strong><span class=\"math-tex\">$\\sin\\alpha$<\/span> . <span class=\"math-tex\">$\\cot\\alpha$<\/span> &lt; 0","<strong>C. <\/strong><span class=\"math-tex\">$\\sin\\alpha$<\/span> . <span class=\"math-tex\">$\\cos\\alpha$<\/span> &gt; 0","<strong>D. <\/strong><span class=\"math-tex\">$\\sin\\alpha$<\/span> v&agrave; <span class=\"math-tex\">$\\tan\\alpha$<\/span> c&ugrave;ng d\u1ea5u"],"correct":"2","level":"1","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.&nbsp;<\/strong><span class=\"math-tex\">$\\sin\\alpha$<\/span>&nbsp;.&nbsp;<span class=\"math-tex\">$\\cot\\alpha$<\/span>&nbsp;&lt; 0<\/span><\/p><p>V\u1edbi&nbsp;<span class=\"math-tex\">$\\alpha \\in (90^o; 180^o)$<\/span>, ta c&oacute;&nbsp;<span class=\"math-tex\">$\\sin\\alpha$<\/span>&nbsp;&gt; 0,&nbsp;<span class=\"math-tex\">$\\cos\\alpha$<\/span>&nbsp;&lt; 0.<\/p><p>Suy ra&nbsp;<span class=\"math-tex\">$\\tan\\alpha$<\/span>&nbsp;&lt; 0,&nbsp;<span class=\"math-tex\">$\\cot\\alpha$<\/span>&nbsp;&lt; 0.<\/p><p>V\u1eady&nbsp;<span style=\"color:#16a085;\"><span class=\"math-tex\">$\\sin\\alpha$<\/span>&nbsp;.&nbsp;<span class=\"math-tex\">$\\cot\\alpha$<\/span>&nbsp;&lt; 0<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-04-14 01:18:52","option_type":"math","len":0},{"id":"7473","mon_id":"1158767","chapter_id":"1159257","post_id":"7300","question":"<p>Cho&nbsp;&alpha; l&agrave; g&oacute;c t&ugrave;. M\u1ec7nh \u0111\u1ec1 n&agrave;o <strong>\u0111&uacute;ng <\/strong>trong c&aacute;c m\u1ec7nh \u0111\u1ec1 sau?<\/p>","options":["<strong>A. <\/strong><span class=\"math-tex\">$\\tan\\alpha &lt;0$<\/span>","<strong>B. <\/strong><span class=\"math-tex\">$\\cot\\alpha > 0$<\/span>","<strong>C. <\/strong><span class=\"math-tex\">$\\sin\\alpha &lt;0$<\/span>","<strong>D. <\/strong><span class=\"math-tex\">$\\cos\\alpha >0$<\/span>"],"correct":"1","level":"1","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>A.&nbsp;<\/strong><span class=\"math-tex\">$\\tan\\alpha &lt;0$<\/span><\/span><\/p><p>V&igrave;&nbsp;&alpha; l&agrave; g&oacute;c t&ugrave; n&ecirc;n&nbsp;<span class=\"math-tex\">$\\sin\\alpha >0$<\/span>,&nbsp;<span class=\"math-tex\">$\\cos\\alpha < 0$<\/span>&nbsp;suy ra&nbsp;<span style=\"color:#16a085;\"><span class=\"math-tex\">$\\tan\\alpha &lt;0$<\/span><\/span>, <span class=\"math-tex\">$\\cot\\alpha < 0$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-04-14 01:20:37","option_type":"math","len":0},{"id":"7475","mon_id":"1158767","chapter_id":"1159257","post_id":"7300","question":"<p>Cho&nbsp;<span class=\"math-tex\">$0^o < \\alpha < 90^o$<\/span>. Kh\u1eb3ng \u0111\u1ecbnh n&agrave;o sau \u0111&acirc;y <strong>\u0111&uacute;ng<\/strong>?<\/p>","options":["<strong>A. <\/strong><span class=\"math-tex\">$\\cot (90^o-\\alpha )=-\\tan\\alpha$<\/span>","<strong>B. <\/strong><span class=\"math-tex\">$\\cos (90^o-\\alpha )=\\sin\\alpha$<\/span>","<strong>C. <\/strong><span class=\"math-tex\">$\\sin(90^o-\\alpha )=-\\cos\\alpha$<\/span>","<strong>D. <\/strong><span class=\"math-tex\">$\\tan(90^o-\\alpha )=-\\cot\\alpha$<\/span>"],"correct":"2","level":"1","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.&nbsp;<\/strong><span class=\"math-tex\">$\\cos (90^o-\\alpha )=\\sin\\alpha$<\/span><\/span><\/p><p>V&igrave;&nbsp;<span class=\"math-tex\">$\\alpha$<\/span>&nbsp;v&agrave;&nbsp;<span class=\"math-tex\">$90^o-\\alpha$<\/span>&nbsp;l&agrave; hai ph\u1ee5 nhau n&ecirc;n theo t&iacute;nh ch\u1ea5t gi&aacute; tr\u1ecb l\u01b0\u1ee3ng gi&aacute;c c\u1ee7a hai cung&nbsp;ph\u1ee5 nhau ta c&oacute;&nbsp;<span style=\"color:#16a085;\"><span class=\"math-tex\">$\\cos (90^o-\\alpha )=\\sin\\alpha$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-04-14 01:27:25","option_type":"math","len":0}]}