{"common":{"save":0,"post_id":"6441","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6588","mon_id":"1158767","chapter_id":"1158885","post_id":"6441","question":"<p>K\u1ebft qu\u1ea3 \u0111o chi\u1ec1u dài c\u1ee7a m\u1ed9t cây c\u1ea7u \u0111\u01b0\u1ee3c ghi là 152m <span class=\"math-tex\">$\\pm$<\/span> 0,2m, \u0111i\u1ec1u \u0111ó có ngh\u0129a là gì?<\/p>","options":["<strong>A.<\/strong> Chi\u1ec1u dài \u0111úng c\u1ee7a cây c\u1ea7u là m\u1ed9t s\u1ed1 n\u1eb1m trong kho\u1ea3ng 151,8m \u0111\u1ebfn 152,2m.","<strong>B.<\/strong> Chi\u1ec1u dài \u0111úng c\u1ee7a cây c\u1ea7u là m\u1ed9t s\u1ed1 l\u1edbn h\u01a1n 152m.","<strong>C.<\/strong> Chi\u1ec1u dài \u0111úng c\u1ee7a cây c\u1ea7u là m\u1ed9t s\u1ed1 nh\u1ecf h\u01a1n 152m.","<strong>D.<\/strong> Chi\u1ec1u dài \u0111úng c\u1ee7a cây c\u1ea7u là 151,8m ho\u1eb7c 152,2m."],"correct":"1","level":"1","hint":"<p>K\u1ebft qu\u1ea3 \u0111o chi\u1ec1u dài c\u1ee7a m\u1ed9t cây c\u1ea7u \u0111\u01b0\u1ee3c ghi là 152m <span class=\"math-tex\">$\\pm$<\/span> 0,2m, \u0111i\u1ec1u \u0111ó có ngh\u0129a là chi\u1ec1u dài \u0111úng c\u1ee7a cây c\u1ea7u là m\u1ed9t s\u1ed1 n\u1eb1m trong kho\u1ea3ng 151,8m \u0111\u1ebfn 152,2m.<\/p>","answer":"<p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>A.<\/strong> Chi\u1ec1u dài \u0111úng c\u1ee7a cây c\u1ea7u là m\u1ed9t s\u1ed1 n\u1eb1m trong kho\u1ea3ng 151,8m \u0111\u1ebfn 152,2m.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-05-22 05:32:00","option_type":"txt","len":3},{"id":"6589","mon_id":"1158767","chapter_id":"1158885","post_id":"6441","question":"<p>Khi tính di\u1ec7n tích hình tròn bán kính R = 3 cm, n\u1ebfu l\u1ea5y <span class=\"math-tex\">$\\pi$<\/span> = 3,14 thì \u0111\u1ed9 chính xác là bao nhiêu?<\/p>","options":["<strong>A.<\/strong> d = 0,009","<strong>B.<\/strong> d = 0,09","<strong>C.<\/strong> d = 0,1","<strong>D. <\/strong>d = 0,01"],"correct":"2","level":"1","hint":"<p>Công th\u1ee9c tính di\u1ec7n tích hính tròn là S = <span class=\"math-tex\">$\\pi$<\/span> . R² .<\/p>","answer":"<p>Ta có di\u1ec7n tích hình tròn S = 3,14 . 3² = 28,26 và <span class=\"math-tex\">$\\overline{S}$<\/span> = <span class=\"math-tex\">$\\pi$<\/span> . 3² = 9<span class=\"math-tex\">$\\pi$<\/span> .<br \/>Ta có: 3,14 < <span class=\"math-tex\">$\\pi$<\/span> < 3,15 ⇒ 3,14 . 9 < 9<span class=\"math-tex\">$\\pi$<\/span> < 3,15 . 9 ⇒ 28,26 < <span class=\"math-tex\">$\\overline{S}$<\/span> < 28,35 . <br \/>Do \u0111ó: <span class=\"math-tex\">$\\overline{S} - S=\\overline{S}-28,26 < 28,35-28,26=0,09$<\/span><br \/>⇒ <span class=\"math-tex\">$\\Delta(S)=|\\overline{S}-S|<0,09$<\/span> .<br \/>V\u1eady n\u1ebfu ta l\u1ea5y <span class=\"math-tex\">$\\pi$<\/span> = 3,14 thì di\u1ec7n tích hình tròn là S = 28,26 cm² v\u1edbi \u0111\u1ed9 chính xác d = 0,09.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>B.<\/strong> d = 0,09<\/span> .<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-05-27 01:55:14","option_type":"txt","len":1},{"id":"6591","mon_id":"1158767","chapter_id":"1158885","post_id":"6441","question":"<p>Cho giá tr\u1ecb g\u1ea7n \u0111úng c\u1ee7a <span class=\"math-tex\">$\\dfrac{8}{17}$<\/span> là 0,47. Sai s\u1ed1 tuy\u1ec7t \u0111\u1ed1i c\u1ee7a 0,47 là<\/p>","options":["<strong>A.<\/strong> 0,001","<strong>B.<\/strong> 0,002","<strong>C.<\/strong> 0,003","<strong>D.<\/strong> 0,004"],"correct":"1","level":"1","hint":"","answer":"<p>Ta có <span class=\"math-tex\">$\\bigg|0,47-\\dfrac{8}{17}\\bigg| < 0,00059$<\/span> . Suy ra sai s\u1ed1 tuy\u1ec7t \u0111\u1ed1i c\u1ee7a 0,47 là 0,001.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>A.<\/strong> 0,001<\/span> .<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-05-27 02:00:22","option_type":"txt","len":0}]}