{"segment":[{"time":24,"part":[{"title":"Cho h\u00e0m s\u1ed1 $y=-3{{x}^{2}}$. ","title_trans":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","temp":"true_false","correct":[["t","f","f","t"]],"list":[{"point":5,"image":"img\/1.png","col_name":["","\u0110\u00fang","Sai"],"arr_ques":["1. H\u00e0m s\u1ed1 ngh\u1ecbch bi\u1ebfn khi $x>0$ v\u00e0 \u0111\u1ed3ng bi\u1ebfn khi $x < 0$","2. $y<0$ v\u1edbi m\u1ecdi $x$","3. Khi $x=-\\dfrac{1}{3}$ th\u00ec $y=\\dfrac{1}{3}$ ","4. Gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a h\u00e0m s\u1ed1 l\u00e0 $y=0$"],"hint":"D\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t c\u1ee7a h\u00e0m s\u1ed1 $y=ax^2$ khi $a<0$","explain":["1. \u0110\u00fang v\u00ec $a = -3 <0$ n\u00ean h\u00e0m s\u1ed1 ngh\u1ecbch bi\u1ebfn khi $x>0$ v\u00e0 \u0111\u1ed3ng bi\u1ebfn khi $x<0.$ ","<br\/>2. Sai v\u00ec $y=-3{{x}^{2}}\\le 0$ v\u1edbi m\u1ecdi $x$ v\u00e0 $y<0$ v\u1edbi m\u1ecdi $x\\ne 0$ .","<br\/>3. Sai v\u00ec khi ta thay $x=-\\dfrac{1}{3}$ v\u00e0o h\u00e0m s\u1ed1 th\u00ec $y=-3.{{\\left( -\\dfrac{1}{3} \\right)}^{2}}=-\\dfrac{1}{3}$.","<br\/>4. \u0110\u00fang v\u00ec $y=-3{{x}^{2}}\\le 0$ n\u00ean gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a h\u00e0m s\u1ed1 l\u00e0 $0.$"]}]}],"id_ques":771},{"time":24,"part":[{"title":"Ch\u1ecdn kh\u1eb3ng \u0111\u1ecbnh sai","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"<span class='basic_left'>Cho h\u00e0m s\u1ed1 $y=f\\left( x \\right)=\\dfrac{{{x}^{2}}}{4}$ . <\/span>","select":["A. $f\\left( 0 \\right)=0$ ","B. $f\\left( -1 \\right)=\\dfrac{1}{4}$ ","C. $f\\left( 2 \\right)=1$","D. $f\\left( -4 \\right)=-4$ "],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>T\u00ednh c\u00e1c gi\u00e1 tr\u1ecb $f\\left( 0 \\right);$ $f\\left( -1 \\right);$ $f\\left( 2 \\right);$ v\u00e0 $f\\left( -4 \\right)$ <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>+ $f\\left( 0 \\right)=\\dfrac{{{0}^{2}}}{4}=0$<br\/> Suy ra kh\u1eb3ng \u0111\u1ecbnh A \u0111\u00fang<br\/>+ $f\\left( -1 \\right)=\\dfrac{{{\\left( -1 \\right)}^{2}}}{4}=\\dfrac{1}{4}$<br\/> Suy ra kh\u1eb3ng \u0111\u1ecbnh B \u0111\u00fang<br\/>+ $f\\left( 2 \\right)=\\dfrac{{{2}^{2}}}{4}=1$<br\/> Suy ra kh\u1eb3ng \u0111\u1ecbnh C \u0111\u00fang<br\/>+ $f\\left( -4 \\right)=\\dfrac{{{\\left( -4 \\right)}^{2}}}{4}=4\\ne -4$ <br\/>Suy ra kh\u1eb3ng \u0111\u1ecbnh D sai<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 D<\/span><br\/><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/> V\u00ec v\u1edbi m\u1ecdi $x$ th\u00ec $y=f\\left( x \\right)=\\dfrac{{{x}^{2}}}{4} \\ge 0$<br\/> Do \u0111\u00f3 ta c\u00f3 th\u1ec3 ch\u1ecdn ngay \u0111\u00e1p \u00e1n l\u00e0 D m\u00e0 kh\u00f4ng c\u1ea7n tr\u1ef1c ti\u1ebfp t\u00ednh c\u00e1c gi\u00e1 tr\u1ecb.<\/span><\/span>","column":2}]}],"id_ques":772},{"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":"<span class='basic_left'>Cho h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$ . \u0110i\u1ec3m <b>kh\u00f4ng thu\u1ed9c<\/b> \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 l\u00e0<\/span> ","select":["A. $M\\left( -1;\\dfrac{3}{2} \\right)$","B. $N\\left( 2;6 \\right)$ ","C. $Q(2;4)$","D. $P\\left( 1;1,5 \\right)$ "],"hint":"Thay c\u00e1c t\u1ecda \u0111\u1ed9 \u0111i\u1ec3m $M, N, P, Q$ v\u00e0o h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$. \u0110i\u1ec3m n\u00e0o kh\u00f4ng th\u1ecfa m\u00e3n ph\u01b0\u01a1ng tr\u00ecnh th\u00ec kh\u00f4ng thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1","explain":"<span class='basic_left'>+ Thay t\u1ecda \u0111\u1ed9 \u0111i\u1ec3m $M\\left( -1;\\dfrac{3}{2} \\right)$ v\u00e0o h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$, ta c\u00f3: $\\dfrac{3}{2}=\\dfrac{3}{2}.{{\\left( -1 \\right)}^{2}}$ (\u0111\u00fang).<br\/> Suy ra $M$ <b>thu\u1ed9c <\/b> \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$<br\/>+ Thay t\u1ecda \u0111\u1ed9 \u0111i\u1ec3m $N\\left( 2;6 \\right)$ v\u00e0o h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$, ta c\u00f3: $6=\\dfrac{3}{2}{{.2}^{2}}$ (\u0111\u00fang).<br\/> Suy ra $N$ <b>thu\u1ed9c <\/b> \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$<br\/>+ Thay t\u1ecda \u0111\u1ed9 \u0111i\u1ec3m $Q(2;4)$ v\u00e0o h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$, ta c\u00f3: $4=\\dfrac{3}{2}{{.2}^{2}}\\Leftrightarrow 4=6$ (sai). <br\/>Suy ra $Q$ <b>kh\u00f4ng thu\u1ed9c <\/b> \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$<br\/>+ Thay t\u1ecda \u0111\u1ed9 \u0111i\u1ec3m $P\\left( 1;1,5 \\right)$ v\u00e0o h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$, ta c\u00f3: $1,5=\\dfrac{3}{2}{{.1}^{2}}$ (\u0111\u00fang).<br\/> Suy ra $P$ <b>thu\u1ed9c <\/b> \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=\\dfrac{3}{2}{{x}^{2}}$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C<\/span><\/span>","column":2}]}],"id_ques":773},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["0"],["0"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"<span class='basic_left'>Cho h\u00e0m s\u1ed1 $y=-\\dfrac{2}{3}{{x}^{2}}$ . <br\/> Gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a h\u00e0m s\u1ed1 l\u00e0 _input_ khi $x=$_input_<\/span>","hint":"","explain":"<span class='basic_left'>Ta c\u00f3: $y=-\\dfrac{2}{3}{{x}^{2}} \\le 0$ v\u1edbi m\u1ecdi $x$<br\/>Suy ra h\u00e0m s\u1ed1 c\u00f3 gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t l\u00e0 $0$.<br\/> Ta c\u00f3 $y=0$ khi $x=0$ <br\/>V\u1eady gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a h\u00e0m s\u1ed1 l\u00e0 $0$ khi $x=0$ <br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $0$ v\u00e0 $0$<\/span><\/span>"}]}],"id_ques":774},{"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":"<span class='basic_left'>Cho h\u00e0m s\u1ed1 $y=f\\left( x \\right)=-5{{x}^{2}}$ .<br\/>B\u1ea1n H\u1eb1ng t\u00ednh \u0111\u01b0\u1ee3c $f\\left( -3 \\right)=-5.{{\\left( -3 \\right)}^{2}}=-45;f\\left( 2 \\right)=-{{5.2}^{2}}=-20$ v\u00e0 k\u1ebft lu\u1eadn r\u1eb1ng h\u00e0m s\u1ed1 \u0111\u1ed3ng bi\u1ebfn.<br\/>B\u1ea1n Ti\u1ebfn t\u00ednh \u0111\u01b0\u1ee3c $f\\left( -1 \\right)=-5.{{\\left( -1 \\right)}^{2}}=-5$ v\u00e0 $f\\left( 2 \\right)=-20$ n\u00ean k\u1ebft lu\u1eadn h\u00e0m s\u1ed1 ngh\u1ecbch bi\u1ebfn. <br\/>V\u1eady ai \u0111\u00fang, ai sai?","select":["A. H\u1eb1ng \u0111\u00fang, Ti\u1ebfn sai","B. H\u1eb1ng sai, Ti\u1ebfn \u0111\u00fang","C. C\u1ea3 hai b\u1ea1n \u0111\u1ec1u sai"],"hint":"","explain":"<span class='basic_left'>\u0110\u1ec3 x\u00e9t t\u00ednh \u0111\u1ed3ng bi\u1ebfn hay ngh\u1ecbch bi\u1ebfn c\u1ee7a h\u00e0m s\u1ed1 $y=ax^2$, ta l\u1ea5y hai gi\u00e1 tr\u1ecb b\u1ea5t k\u00ec c\u00f9ng \u00e2m ho\u1eb7c c\u00f9ng d\u01b0\u01a1ng c\u1ee7a bi\u1ebfn s\u1ed1 $x$ r\u1ed3i so s\u00e1nh hai gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a $y.$ V\u00ec th\u1ebf v\u1edbi c\u00e1ch ch\u1ecdn c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a $x$ nh\u01b0 hai b\u1ea1n \u0111\u00e3 l\u00e0m th\u00ec kh\u00f4ng th\u1ec3 cho ta k\u1ebft lu\u1eadn r\u1eb1ng h\u00e0m s\u1ed1 \u0111\u1ed3ng bi\u1ebfn hay h\u00e0m s\u1ed1 ngh\u1ecbch bi\u1ebfn. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C<\/span><br\/><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/>H\u00e0m s\u1ed1 \u0111\u00e3 cho c\u00f3 h\u1ec7 s\u1ed1 $a=-5<0$ n\u00ean h\u00e0m s\u1ed1 ngh\u1ecbch bi\u1ebfn khi $x>0$ v\u00e0 \u0111\u1ed3ng bi\u1ebfn khi $x<0.$<\/span>","column":3}]}],"id_ques":775},{"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":" Cho h\u00e0m s\u1ed1 $y=f\\left( x \\right)=1,5{{x}^{2}}$ . <br\/>H\u00e3y s\u1eafp x\u1ebfp c\u00e1c gi\u00e1 tr\u1ecb sau theo th\u1ee9 t\u1ef1 gi\u1ea3m d\u1ea7n:$f\\left( -1 \\right);f\\left( -\\dfrac{2}{3} \\right);f\\left( -2 \\right);f\\left( -\\dfrac{3}{5} \\right)$ ","select":["A. $f\\left( -1 \\right);f\\left( -2 \\right);f\\left( -\\dfrac{2}{3} \\right);f\\left( -\\dfrac{3}{5} \\right)$","B. $f\\left( -\\dfrac{3}{5} \\right);f\\left( -\\dfrac{2}{3} \\right);f\\left( -1 \\right);f\\left( -2 \\right)$ ","C. $f\\left( -2 \\right);f\\left( -1 \\right);f\\left( -\\dfrac{2}{3} \\right);f\\left( -\\dfrac{3}{5} \\right)$ ","D. $f\\left( -2 \\right);f\\left( -\\dfrac{2}{3} \\right); f\\left( -1 \\right);f\\left( -\\dfrac{3}{5} \\right)$"],"hint":"D\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t ngh\u1ecbch bi\u1ebfn c\u1ee7a h\u00e0m s\u1ed1 khi $a>0$","explain":"<span class='basic_left'> Ta c\u00f3 $a=1,5>0$ n\u00ean khi $x<0$ th\u00ec h\u00e0m s\u1ed1 lu\u00f4n ngh\u1ecbch bi\u1ebfn.<br\/>M\u00e0 $-2<-1<-\\dfrac{2}{3}<-\\dfrac{3}{5}$ n\u00ean $f\\left( -2 \\right)>f\\left( -1 \\right)>f\\left( -\\dfrac{2}{3} \\right)>f\\left( -\\dfrac{3}{5} \\right)$<br\/> V\u1eady c\u00e1c gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp theo th\u1ee9 t\u1ef1 gi\u1ea3m d\u1ea7n l\u00e0 $f\\left( -2 \\right);f\\left( -1 \\right);f\\left( -\\dfrac{2}{3} \\right);f\\left( -\\dfrac{3}{5} \\right).$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C<\/span><br\/><span class='basic_green'>L\u01b0u \u00fd:<\/span><br\/>Ta c\u00f3 th\u1ec3 t\u00ednh tr\u1ef1c ti\u1ebfp c\u00e1c gi\u00e1 tr\u1ecb tr\u00ean r\u1ed3i so s\u00e1nh<\/span>","column":2}]}],"id_ques":776},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["3"],["-1"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"Cho h\u00e0m s\u1ed1 $y=f\\left( x \\right)={{x}^{2}}$. T\u00ecm $a\\in \\mathbb{R}$ bi\u1ebft $f\\left( a-1 \\right)=4$ <br\/><b> \u0110\u00e1p s\u1ed1: <\/b> $a \\in $ {_input_ ; _input_}","hint":"","explain":"<span class='basic_left'> Ta c\u00f3: $f\\left( a-1 \\right)={{\\left( a-1 \\right)}^{2}}$ <br\/>$f\\left( a-1 \\right)=4\\Leftrightarrow {{\\left( a-1 \\right)}^{2}}=4\\Leftrightarrow \\left[ \\begin{aligned} & a-1=2 \\\\ & a-1=-2 \\\\ \\end{aligned} \\right.\\Leftrightarrow \\left[ \\begin{aligned} & a=3 \\\\ & a=-1 \\\\ \\end{aligned} \\right.$<br\/>V\u1eady $ a =3$ ho\u1eb7c $a = -1$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $3$ v\u00e0 $-1$<\/span><\/span>"}]}],"id_ques":777},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["2"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"Cho h\u00e0m s\u1ed1 $y=\\left( m+2 \\right){{x}^{2}}$ ( $m\\ne -2$). T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a $m$ \u0111\u1ec3 h\u00e0m s\u1ed1 c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 $4$ khi $x=-1$<br\/><b> \u0110\u00e1p s\u1ed1: <\/b> $m=$ _input_ ","hint":"","explain":"<span class='basic_left'> V\u00ec h\u00e0m s\u1ed1 c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 $4$ khi $x=-1$ n\u00ean ta thay $x=-1$ v\u00e0 $y=4$ v\u00e0o h\u00e0m s\u1ed1 $y=\\left( m+2 \\right){{x}^{2}}$, ta \u0111\u01b0\u1ee3c:<br\/>$4=\\left( m+2 \\right){{\\left( -1 \\right)}^{2}}\\Leftrightarrow m+2=4\\Leftrightarrow m=2$ (th\u1ecfa m\u00e3n $m\\ne -2$)<br\/>V\u1eady $m=2$ th\u00ec h\u00e0m s\u1ed1 c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 $4$ khi $x=-1$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $2$ <\/span><\/span>"}]}],"id_ques":778},{"time":24,"part":[{"title":"\u0110i\u1ec1n c\u00e1c s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n d\u01b0\u1edbi d\u1ea1ng s\u1ed1 nguy\u00ean ho\u1eb7c s\u1ed1 th\u1eadp ph\u00e2n","temp":"fill_the_blank","correct":[[["-13,5"],["-6"],["-1,5"],["0"],["-1,5"],["-6"],["-13,5"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"\u0110i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng c\u00e1c gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a $y=-\\dfrac{3}{2}{{x}^{2}}$ trong b\u1ea3ng sau:<br\/><table> <tr> <td>$x$<\/td> <td>$-3$<\/td> <td>$-2$<\/td> <td>$-1$<\/td><td>$0$<\/td><td>$1$<\/td> <td>$2$<\/td><td>$3$<\/td><\/tr> <tr><td>$y=-\\dfrac{3}{2}{{x}^{2}}$<\/td><td>_input_<\/td><td>_input_<\/td> <td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><\/tr> <\/table>","hint":"","explain":"<span class='basic_left'> \u0110\u1eb7t $y=f\\left( x \\right)=-\\dfrac{3}{2}{{x}^{2}}$ <br\/> Do t\u00ednh \u0111\u1ed1i x\u1ee9ng cu\u1ea3 \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=ax^2$ qua tr\u1ee5c $Oy$ n\u00ean $f(x)=f(-x).$<br\/> Khi \u0111\u00f3 <br\/>$f\\left( -3 \\right)=f\\left( 3 \\right)=-\\dfrac{3}{2}{{.3}^{2}}=-\\dfrac{27}{2}=-13,5$ <br\/>$f\\left( -2 \\right)=f\\left( 2 \\right)=-\\dfrac{3}{2}{{.2}^{2}}=-6$<br\/> $f\\left( -1 \\right)=f\\left( 1 \\right)=-\\dfrac{3}{2}{{.1}^{2}}=-\\dfrac{3}{2}=-1,5$<br\/> Ta c\u00f3: $f\\left( 0 \\right)=-\\dfrac{3}{2}.0=0$ <br\/><span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $-13,5;$ $-6;$ $-1,5;$ $0;$ $-1,5;$ $-6;$ $-13,5.$<\/span><\/span>"}]}],"id_ques":779},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"select":["A. $\\dfrac{1}{4}$","B. $\\dfrac{1}{2}$","C. $\\dfrac{3}{4}$"],"ques":"<span class='basic_left'>Cho h\u00e0m s\u1ed1 $y=f\\left( x \\right)=\\dfrac{{{x}^{2}}}{4}$ <br\/><b> C\u00e2u 1: <\/b>T\u00ednh $f\\left( -1 \\right)$ <br\/>","hint":"","explain":"<span class='basic_left'>Ta c\u00f3 $y=f\\left( x \\right)=\\dfrac{{{x}^{2}}}{4}$<br\/>Suy ra $f\\left( -1 \\right)=\\dfrac{{{\\left( -1 \\right)}^{2}}}{4}=\\dfrac{1}{4}$ <br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0 $\\dfrac{1}{4}$<\/span>. "}]}],"id_ques":780},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank_random","correct":[[["8"],["-8"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"Cho h\u00e0m s\u1ed1 $y=f\\left( x \\right)=\\dfrac{{{x}^{2}}}{4}$ <br\/><b> C\u00e2u 2: <\/b>T\u00ecm $x$ bi\u1ebft $y=16$ <br\/><b> \u0110\u00e1p s\u1ed1: <\/b>$x \\in$ {_input_;_input_}","hint":"","explain":"<span class='basic_left'>Ta c\u00f3 $y=16$<br\/> $\\begin{align} & \\Leftrightarrow \\dfrac{{{x}^{2}}}{4}=16 \\\\ & \\Leftrightarrow {{x}^{2}}=64 \\\\ & \\Leftrightarrow x=\\pm 8 \\\\ \\end{align}$<br\/>V\u1eady $x=\\pm 8$<br\/><span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0 $8;-8$<\/span><\/span>. "}]}],"id_ques":781},{"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":" \u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=a{{x}^{2}}$ $\\left( a\\ne 0 \\right)$ l\u00e0","select":["<span class='basic_left'>A. \u0110\u01b0\u1eddng cong \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 v\u00e0 nh\u1eadn $Ox$ l\u00e0m tr\u1ee5c \u0111\u1ed1i x\u1ee9ng","<span class='basic_left'>B. \u0110\u01b0\u1eddng cong \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 v\u00e0 nh\u1eadn $Oy$ l\u00e0m tr\u1ee5c \u0111\u1ed1i x\u1ee9ng ","<span class='basic_left'>C. \u0110\u01b0\u1eddng th\u1eb3ng \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 v\u00e0 nh\u1eadn $Oy$ l\u00e0m tr\u1ee5c \u0111\u1ed1i x\u1ee9ng ","<span class='basic_left'>D. \u0110\u01b0\u1eddng cong \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 v\u00e0 n\u1eb1m ph\u00eda tr\u00ean tr\u1ee5c $Ox.$"],"hint":"","explain":"<span class='basic_left'>\u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=a{{x}^{2}}$ $\\left( a\\ne 0 \\right)$ l\u00e0 \u0111\u01b0\u1eddng cong \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 v\u00e0 nh\u1eadn $Oy$ l\u00e0m tr\u1ee5c \u0111\u1ed1i x\u1ee9ng. <br\/><br\/><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D3.png' \/> $\\hspace{2cm}$ <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D3a.png' \/><br\/> <br\/>+ N\u1ebfu $a>0$ th\u00ec \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 n\u1eb1m ph\u00eda tr\u00ean tr\u1ee5c ho\u00e0nh<br\/>+ N\u1ebfu $a<0$ th\u00ec \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 n\u1eb1m ph\u00eda d\u01b0\u1edbi tr\u1ee5c ho\u00e0nh<br\/>Suy ra c\u00e1c kh\u1eb3ng \u0111\u1ecbnh A, C, D sai, kh\u1eb3ng \u0111\u1ecbnh B \u0111\u00fang.<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B<\/span><\/span>","column":1}]}],"id_ques":782},{"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":" H\u00e0m s\u1ed1 $y=2{{x}^{2}}$ c\u00f3 \u0111\u1ed3 th\u1ecb l\u00e0 ","select":["A. <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.1b.png' \/>","B. <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.1.png' \/>","C. <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.1c.png' \/>"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: L\u1eadp b\u1ea3ng gi\u00e1 tr\u1ecb c\u1ee7a h\u00e0m s\u1ed1 t\u1ea1i c\u00e1c \u0111i\u1ec3m $x=0;$ $x=\\pm 1;x=\\pm 2$ <br\/>B\u01b0\u1edbc 2: X\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m trong b\u1ea3ng tr\u00ean m\u1eb7t ph\u1eb3ng t\u1ecda \u0111\u1ed9 r\u1ed3i n\u1ed1i c\u00e1c \u0111i\u1ec3m \u0111\u1ec3 \u0111\u01b0\u1ee3c m\u1ed9t \u0111\u01b0\u1eddng cong l\u00e0 parabol<br\/><b>Ch\u00fa \u00fd:<\/b> L\u1ea5y c\u00e0ng nhi\u1ec1u \u0111i\u1ec3m th\u00ec c\u00e0ng d\u1ec5 v\u1ebd ch\u00ednh x\u00e1c \u0111\u1ed3 th\u1ecb.<br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/>B\u1ea3ng gi\u00e1 tr\u1ecb c\u1ee7a h\u00e0m s\u1ed1:<br\/><table> <tr> <td>$x$<\/td> <td>$-2$<\/td> <td>$-1$<\/td><td>$0$<\/td><td>$1$<\/td> <td>$2$<\/td><\/tr> <tr><td>$y=2{{x}^{2}}$<\/td><td>$8$<\/td><td>$2$<\/td> <td>$0$<\/td><td>$2$<\/td><td>$8$<\/td><\/tr> <\/table><br\/>\u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1:<br\/><br\/><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.1.png' \/><\/center> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B<\/span><\/span>","column":3}]}],"id_ques":783},{"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":" H\u00e0m s\u1ed1 $y=-\\dfrac{{{x}^{2}}}{2}$ c\u00f3 \u0111\u1ed3 th\u1ecb l\u00e0 ","select":["A. <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.1b.png' \/>","B. <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.1c.png' \/>","C. <img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.2a.png' \/>"],"hint":"","explain":"<span class='basic_left'>B\u1ea3ng gi\u00e1 tr\u1ecb c\u1ee7a h\u00e0m s\u1ed1:<br\/><table> <tr> <td>$x$<\/td> <td>$-2$<\/td> <td>$-1$<\/td><td>$0$<\/td><td>$1$<\/td> <td>$2$<\/td><\/tr> <tr><td>$y=-\\dfrac{{{x}^{2}}}{2}$<\/td><td>$-2$<\/td><td>$-\\dfrac{1}{2}$ <\/td> <td>$0$<\/td><td>$-\\dfrac{1}{2}$ <\/td><td>$-2$<\/td><\/tr> <\/table><br\/>\u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1:<br\/><br\/><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.2a.png' \/><\/center> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C<\/span><\/span>","column":3}]}],"id_ques":784},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1ecda \u0111\u1ed9 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"<b>V\u00ed d\u1ee5: <\/b> B\u1ea1n t\u00ecm \u0111\u01b0\u1ee3c giao \u0111i\u1ec3m c\u00f3 t\u1ecda \u0111\u1ed9 $(9;2)$ th\u00ec ta \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $(9;2)$. <br\/>Ch\u00fa \u00fd: \u0110i\u1ec1n c\u1ea3 d\u1ea5u ngo\u1eb7c tr\u00f2n v\u00e0 d\u1ea5u ; nh\u01b0 m\u1eabu tr\u00ean.","temp":"fill_the_blank_random","correct":[[["(0;0)"],["(2;4)"]]],"list":[{"point":5,"width":70,"type_input":"","ques":"<span class='basic_left'>Cho hai h\u00e0m s\u1ed1 $y={{x}^{2}}$ v\u00e0 $y=2x$. B\u1eb1ng minh h\u1ecda h\u00ecnh h\u1ecdc, h\u00e3y x\u00e1c \u0111\u1ecbnh giao \u0111i\u1ec3m hai \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 tr\u00ean.<br\/><b> \u0110\u00e1p s\u1ed1:<\/b> Giao \u0111i\u1ec3m c\u1ee7a hai \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 \u0111\u00e3 cho l\u00e0 _input_ v\u00e0 _input_","hint":"","explain":"<span class='basic_left'> B\u1ea3ng gi\u00e1 tr\u1ecb c\u00e1c h\u00e0m s\u1ed1:<br\/><table> <tr> <td>$x$<\/td> <td>$0$<\/td> <td>$1$<\/td><\/tr> <tr><td>$y=2x$<\/td><td>$0$<\/td><td>$2$ <\/td> <\/tr> <\/table><br\/><table> <tr> <td>$x$<\/td> <td>$-2$<\/td> <td>$-1$<\/td><td>$0$<\/td><td>$1$<\/td> <td>$2$<\/td><\/tr> <tr><td>$y={{x}^{2}}$<\/td><td>$4$<\/td><td>$1$ <\/td> <td>$0$<\/td><td>$1$<\/td><td>$4$<\/td><\/tr> <\/table><br\/>\u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=2x$ l\u00e0 \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 $O$ v\u00e0 \u0111i\u1ec3m $(1;2)$.<br\/>\u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y={{x}^{2}}$ l\u00e0 \u0111\u01b0\u1eddng cong \u0111i qua $O$ v\u00e0 c\u00e1c \u0111i\u1ec3m trong b\u1ea3ng gi\u00e1 tr\u1ecb<br\/><br\/><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/daiso/bai19/lv1/img\/D6.3.png' \/><\/center><br\/><br\/>D\u1ef1a v\u00e0o h\u00ecnh v\u1ebd hai \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1, ta suy ra giao \u0111i\u1ec3m c\u1ee7a hai \u0111\u1ed3 th\u1ecb l\u00e0 g\u1ed1c t\u1ecda \u0111\u1ed9 $O(0;0)$ v\u00e0 \u0111i\u1ec3m $M(2;4)$<br\/><span class='basic_pink'>V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 $(0;0)$ v\u00e0 $(2;4)$<\/span><\/span>"}]}],"id_ques":785},{"time":24,"part":[{"time":3,"title":"N\u1ed1i t\u1eeb ho\u1eb7c c\u1ee5m t\u1eeb \u1edf c\u1ed9t b\u00ean tr\u00e1i v\u1edbi c\u1ed9t b\u00ean ph\u1ea3i \u0111\u1ec3 \u0111\u01b0\u1ee3c c\u00e2u ho\u00e0n ch\u1ec9nh","title_trans":"","audio":"","temp":"matching","correct":[["3","1","2"]],"list":[{"point":5,"image":"img\/1.png","left":["Khi $x>0,$ h\u00e0m s\u1ed1 $y=\\left( 2m-1 \\right){{x}^{2}}$ ngh\u1ecbch bi\u1ebfn n\u1ebfu ","Khi $x<0,$ h\u00e0m s\u1ed1 $y=\\left( 2m-6 \\right){{x}^{2}}$ ngh\u1ecbch bi\u1ebfn n\u1ebfu ","H\u00e0m s\u1ed1 $y=\\left( m+2 \\right){{x}^{2}}$ c\u00f3 gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t l\u00e0 $0$ khi "],"right":["$m>3$","$m>-2$","$m<\\dfrac{1}{2}$ "],"top":80,"hint":"","explain":"H\u00e0m s\u1ed1 $y=\\left( 2m-1 \\right){{x}^{2}}$ ngh\u1ecbch bi\u1ebfn khi $x>0$ n\u1ebfu $2m-1<0$$\\Leftrightarrow m<\\dfrac{1}{2}$ <br\/>H\u00e0m s\u1ed1 $y=\\left( 2m-6 \\right){{x}^{2}}$ ngh\u1ecbch bi\u1ebfn khi $x<0$ n\u1ebfu $2m-6>0$$\\Leftrightarrow m>3$<br\/>H\u00e0m s\u1ed1 $y=\\left( m+2 \\right){{x}^{2}}$ c\u00f3 gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t l\u00e0 $0$ khi $m+2>0 \\Leftrightarrow m>-2$"}]}],"id_ques":786},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u $(>,=,<)$ th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[[">"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"<span class='basic_left'>H\u00e0m s\u1ed1 $y=\\left( m-\\dfrac{1}{2} \\right){{x}^{2}}$ \u0111\u1ed3ng bi\u1ebfn khi $x>0$ n\u1ebfu $m$ _input_$\\dfrac{1}{2}$<\/span>","hint":"X\u00e9t d\u1ea5u c\u1ee7a $a$ \u0111\u1ec3 h\u00e0m s\u1ed1 $y=a{{x}^{2}}$ \u0111\u1ed3ng bi\u1ebfn khi $x>0$ ","explain":"<span class='basic_left'>H\u00e0m s\u1ed1 $y=\\left( m-\\dfrac{1}{2} \\right){{x}^{2}}$ \u0111\u1ed3ng bi\u1ebfn khi $x>0$ n\u1ebfu $m-\\dfrac{1}{2}>0\\Leftrightarrow m>\\dfrac{1}{2}$ <br\/><span class='basic_pink'>V\u1eady d\u1ea5u c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $>$<\/span><\/span>"}]}],"id_ques":787},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"\u0110i\u1ec3m $M(-4;-8)$ thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=-\\dfrac{1}{2}{{x}^{2}}$ th\u00ec \u0111i\u1ec3m $M\u2019(4;-8)$ c\u0169ng thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 \u0111\u00f3, <b>\u0111\u00fang<\/b> hay <b>sai<\/b>?","select":["A. \u0110\u00fang ","B. Sai"],"hint":"\u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t: \u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=a{{x}^{2}}$ $\\left( a\\ne 0 \\right)$ nh\u1eadn $Oy$ l\u00e0m tr\u1ee5c \u0111\u1ed1i x\u1ee9ng.","explain":"<span class='basic_left'>\u0110\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=-\\dfrac{1}{2}{{x}^{2}}$ nh\u1eadn $Oy$ l\u00e0m tr\u1ee5c \u0111\u1ed1i x\u1ee9ng. <br\/>Hai \u0111i\u1ec3m $M$ v\u00e0 $M\u2019 $ \u0111\u1ed1i x\u1ee9ng v\u1edbi nhau qua $Oy$ m\u00e0 \u0111i\u1ec3m $M(-4;-8)$ thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y=-\\dfrac{1}{2}{{x}^{2}}$ n\u00ean \u0111i\u1ec3m $M\u2019$ c\u0169ng thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 \u0111\u00f3. <br\/>V\u1eady kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 \u0111\u00fang<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A<\/span><\/span>","column":2}]}],"id_ques":788},{"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":"H\u00e0m s\u1ed1 $y=\\left( {{m}^{2}}+2m+3 \\right){{x}^{2}}$ \u0111\u1ed3ng bi\u1ebfn v\u1edbi m\u1ecdi $x<0$ v\u00e0 ngh\u1ecbch bi\u1ebfn v\u1edbi m\u1ecdi $x>0$, <b>\u0111\u00fang<\/b> hay <b>sai<\/b>?","select":["A. \u0110\u00fang ","B. Sai"],"hint":"H\u00e0m s\u1ed1 c\u00f3 d\u1ea1ng $y=ax^2$, ta \u0111i x\u00e9t d\u1ea5u h\u1ec7 s\u1ed1 $a.$","explain":"<span class='basic_left'>H\u00e0m s\u1ed1 \u0111\u00e3 cho c\u00f3 d\u1ea1ng $y=a{{x}^{2}}$ trong \u0111\u00f3<br\/>$a={{m}^{2}}+2m+3=\\left( {{m}^{2}}+2m+1 \\right)+2={{\\left( m+1 \\right)}^{2}}+2>0$ v\u1edbi m\u1ecdi $m$<br\/>Do \u0111\u00f3 h\u00e0m s\u1ed1 \u0111\u1ed3ng bi\u1ebfn v\u1edbi m\u1ecdi $x>0$ v\u00e0 ngh\u1ecbch bi\u1ebfn v\u1edbi m\u1ecdi $x<0$<br\/>Suy ra kh\u1eb3ng \u0111\u1ecbnh b\u00e0i to\u00e1n l\u00e0 sai.<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 B<\/span><\/span>","column":2}]}],"id_ques":789},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"select":["A. $\\sqrt{2}$","B. $\\sqrt{2}-1$","C. $\\sqrt{2}+1$"],"ques":"<span class='basic_left'>Cho h\u00e0m s\u1ed1 $y=\\left( {{m}^{2}}+2m+3 \\right){{x}^{2}}$ <br\/>Bi\u1ebft r\u1eb1ng khi $x=1$ th\u00ec $y=4$. T\u00ecm $m$ bi\u1ebft $m>0.$<br\/>","hint":"Thay $x=\\pm 1$ v\u00e0 $y=4$ v\u00e0o h\u00e0m s\u1ed1","explain":"<span class='basic_left'>Thay $x=1$ v\u00e0 $y=4$ v\u00e0o h\u00e0m s\u1ed1 $y=\\left( m-\\dfrac{1}{2} \\right){{x}^{2}}$, ta c\u00f3:<br\/>$({m}^2+2m+3) .1^2=4$<br\/>$\\Leftrightarrow {m}^2+2m-1=0$<br\/>$\\Leftrightarrow {(m+1)}^2=2$<br\/>$\\Leftrightarrow \\left[ \\begin{align} & m+1=\\sqrt{2} \\\\ & m+1=-\\sqrt{2} \\\\ \\end{align} \\right.$<br\/>$\\Leftrightarrow \\left[ \\begin{align}& m=\\sqrt{2}-1>0\\\\ & m=-\\sqrt{2}-1<0\\\\ \\end{align} \\right.$<br> Suy ra $m=\\sqrt{2}-1$ (v\u00ec $m>0$)<\/span>"}]}],"id_ques":790}],"lesson":{"save":0,"level":1}}