Hàm số - Level 2

Home Lớp 7 Toán lớp 7 - Sách kết nối tri thức Hàm sốBài tập trung bình

{"common":{"save":0,"post_id":"957","level":2,"total":20,"point":5,"point_extra":0},"segment":[{"id":"681","post_id":"957","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" S\u1ef1 li\u00ean h\u1ec7 gi\u1eefa \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 \u0111\u1ea1i l\u01b0\u1ee3ng $x$ \u0111\u01b0\u1ee3c bi\u1ec3u th\u1ecb b\u1eb1ng c\u00f4ng th\u1ee9c b\u00ean d\u01b0\u1edbi. <br\/> Tr\u01b0\u1eddng h\u1ee3p n\u00e0o $y$ kh\u00f4ng ph\u1ea3i l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a $x$? ","select":["A. $y = f(x) = 3x - 1 $","B. $y = f(x) = 10 $","C. $y = |x| $","D. $|y| = x $"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> C\u1ea7n ki\u1ec3m tra \u0111i\u1ec1u ki\u1ec7n: <\/b> <br\/> M\u1ed7i gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ \u0111\u01b0\u1ee3c t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t v\u00e0 ch\u1ec9 m\u1ed9t gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $y$ hay kh\u00f4ng? <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span> <br\/> Tr\u01b0\u1eddng h\u1ee3p $|y| = x$ kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed1i quan h\u1ec7 h\u00e0m s\u1ed1 gi\u1eefa $y$ v\u00e0 $x$, <br\/> b\u1edfi v\u00ec \u1ee9ng v\u1edbi m\u1ed7i gi\u00e1 tr\u1ecb c\u1ee7a $x > 0,$ c\u00f3 hai gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a $y$. <br\/> V\u00ed d\u1ee5, v\u1edbi $x = 5$ th\u00ec $y = \\pm 5,$ th\u1eadt v\u1eady $|\\pm 5| = 5 $ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:50"},{"id":"682","post_id":"957","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" T\u00ecm t\u1eadp x\u00e1c \u0111\u1ecbnh c\u1ee7a h\u00e0m s\u1ed1: $y = f(x) = \\dfrac{x+1}{x(x+2)}$ ","select":["A. TX\u0110 $= R $","B. TX\u0110 $= \\{ x \\in \\mathbb{R} | x \\neq 0 \\} $","C. TX\u0110 $= \\{ x \\in \\mathbb{R} | x \\neq 0; x \\neq -2 \\} $","D. TX\u0110 $= \\{ x \\in \\mathbb{R} | x \\neq -1 \\} $"],"hint":"X\u00e1c \u0111\u1ecbnh khi m\u1eabu s\u1ed1 kh\u00e1c 0.","explain":" $y = f(x) = \\dfrac{x+1}{x(x+2)}$ c\u00f3 ngh\u0129a <br\/> $ \\Leftrightarrow x(x+2) \\neq 0 \\Leftrightarrow x \\neq 0$ v\u00e0 $x \\neq -2$ <br\/> Hay: TX\u0110 = $ \\{\\forall x \\in \\mathbb{R} | x \\neq 0; x \\neq -2 \\} $ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:50"},{"id":"683","post_id":"957","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"C\u00e1c gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng $x$ v\u00e0 $y$ \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau: <table><td>$x$<\/td><td>$-5$<\/td><td>$-2$<\/td><td>0<\/td><td>3<\/td><td>4<\/td><\/tr><tr><td>$y$<\/td><td>$-7$<\/td><td>$-1$<\/td><td>||<\/td><td>6<\/td><td>9<\/td><\/tr><\/table> \u0110\u1ea1i l\u01b0\u1ee3ng $y$ c\u00f3 ph\u1ea3i l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ kh\u00f4ng? ","select":["C\u00f3 ","Kh\u00f4ng"],"hint":"Xem \u0111\u1ecbnh ngh\u0129a h\u00e0m s\u1ed1. ","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> C\u1ea7n ki\u1ec3m tra \u0111i\u1ec1u ki\u1ec7n: <\/b> <br\/> M\u1ed7i gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ \u0111\u01b0\u1ee3c t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t v\u00e0 ch\u1ec9 m\u1ed9t gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $y$ hay kh\u00f4ng? <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span> <br\/> Trong b\u1ea3ng ta th\u1ea5y gi\u00e1 tr\u1ecb $x = 0$ c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ kh\u00f4ng \u0111\u01b0\u1ee3c t\u01b0\u01a1ng \u1ee9ng v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o c\u1ee7a $y$ n\u00ean $y$ kh\u00f4ng ph\u1ea3i l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a $x$. <br\/><br\/> \u0110\u00e1p \u00e1n l\u00e0 Kh\u00f4ng. <\/span><\/span> ","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:50"}]}