Help meeeeee~
help meeeeee
\(f\left(x\right)=\left(m^2-1\right)x^2-8mx+9-m^2\ge0\)
\(TH1:m^2-1=0\Rightarrow m=\pm1\)
\(m=1\Rightarrow bpt\Leftrightarrow-8x+8\ge0\Leftrightarrow x\le1\left(loại\right)\)
\(m=-1\Rightarrow bpt\Leftrightarrow8x+8\ge0\Leftrightarrow x\ge-1\left(tm\right)\)
\(TH2:m^2-1>0\Leftrightarrow\left[{}\begin{matrix}m>1\\m< -1\end{matrix}\right.\)
\(\Delta=\left(8m\right)^2-4\left(9-m^2\right)\left(m^2-1\right)< 0\Leftrightarrow4x^4+24x^2+36=\left(2x^2\right)^2+2.2x^2.6+6^2=\left(2x^2+6\right)^2>0\left(\forall m\right)\)
\(\Rightarrow x1< x2\le0\Leftrightarrow\)\(\left\{{}\begin{matrix}x1x2\ge0\\x1+x2< 0\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}9-m^2\ge0\\8m< 0\end{matrix}\right.\)
\(\Leftrightarrow-3\le m< 0\Rightarrow-3\le m< -1\)
\(TH3:m^2-1< 0\Leftrightarrow-1< m< 1\)
\(f\left(x\right)\ge0\Leftrightarrow\Delta\le0\Leftrightarrow\left(2x^2+6\right)^2\le0\left(vô-lí\right)\)
\(\Rightarrow-3\le m\le-1\)
Help meeeeee
help meeeeee
Ex5
1 a
2 i
3 b
4
5 g
6 h
7 e
8 d
9 c
10 f
help meeeeee
\(4x^2-12x+6\left(x-3\right)=0\\ 4x\left(x-3\right)+6\left(x-3\right)=0\\ \left(x-3\right)\left(4x+6\right)=0\\ \left[{}\begin{matrix}x-3=0\\4x+6=0\end{matrix}\right.\left[{}\begin{matrix}x=3\\x=-\dfrac{3}{2}\end{matrix}\right.\)
Help meeeeee,cần gấp ạ
1 Nga enjoys collecting coins in her free time
2 There are 54 ethnic groups in VN
3 Sitting in front of a computer all day can cause health problems
4 Some ethnic minoties in the mountains still keep their traditional ways of life
Help meeeeee😭😭😽 Mn ghi rõ tên bài, câu nha❤️
Exer7:
1C 2B 3B 4D 5A 6D 7B 8A 9B 10B
Exer1:
1C 2D 3A 4C 5B 6D 7B 8A 9B
Help meeeeee, 9h mình phải nộp bài cho thầy rồi, các bn ơi, hãy giúp, pleasee.
thế để mình sửa lại vậy, nếu đc, các bn cíu mình nhe
Tìm GTLN của biểu thức : M=|x-3|-|x+1|
HELP MEEEEEE.........
Ta có :/x-3/=/x+1-4/\(\le\)/x+1/+/4/ (bđt về GTTĐ)
nên M\(\le4\)
dấu = xảy ra \(\Leftrightarrow\left(x+1\right).\left(-4\right)\ge0\)
\(\Leftrightarrow x+1\le0\)
\(\Leftrightarrow x\le-1\)
vậy.....
We had a wonderful trip to/in the countryside last week.
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Hình như cả in với to đều đúng hay sao ý