Giải bpt
\(\frac{x^2}{\left(1+\sqrt{1+x}\right)^2}>x-4\)
Những câu hỏi liên quan
giải bpt
\(\left(\sqrt{x+4}-1\right)\sqrt{x+2}\ge\frac{x^3+4x^2+3x-2\left(x+3\right)\sqrt[3]{2x+3}}{\left(\sqrt[3]{2x+3}-3\right)\left(\sqrt{x+4}+1\right)}\)
Giải BPT: \(\sqrt{x^4+x^2+1}+\sqrt{x.\left(x^2-x+1\right)}\le\sqrt{\dfrac{\left(x^2+1\right)^3}{x}}\)
Giải BPT: \(\sqrt{x^4+x^2+1}+\sqrt{x.\left(x^2-x+1\right)}\le\sqrt{\dfrac{\left(x^2+1\right)^3}{x}}\)
Giải BPT: \(\sqrt{x^4+x^2+1}+\sqrt{x.\left(x^2-x+1\right)}\le\sqrt{\dfrac{\left(x^2+1\right)^3}{x}}\)
Giải bpt:
a,\(\frac{\sqrt{x^2-x+4}-2x-3}{x-2}>3\)
b, \(\sqrt{x\left(x-1\right)}+\sqrt{x\left(x+2\right)}\le\sqrt{x\left(4x+1\right)}\)
Giải BPT: \(\left(x-3\right)\left(x+1\right)+2\left(x-3\right)\sqrt{\frac{x+1}{x-3}}< 3\)
ĐKXĐ: \(\left[{}\begin{matrix}x>3\\x\le-1\end{matrix}\right.\)
- Với \(x>3\) BPT tương đương:
\(\left(x-3\right)\left(x+1\right)+2\sqrt{\left(x-3\right)\left(x+1\right)}-3< 0\)
\(\Leftrightarrow\left(\sqrt{\left(x-3\right)\left(x+1\right)}-1\right)\left(\sqrt{\left(x-3\right)\left(x+1\right)}+3\right)< 0\)
\(\Leftrightarrow\left(x-3\right)\left(x+1\right)< 1\)
\(\Leftrightarrow x^2-2x-4< 0\Rightarrow3< x< 1+\sqrt{5}\)
- Với \(x\le-1\)
\(\Leftrightarrow\left(x-3\right)\left(x+1\right)-2\sqrt{\left(x-3\right)\left(x+1\right)}< 3\)
\(\Leftrightarrow\left(\sqrt{\left(x-3\right)\left(x+1\right)}+1\right)\left(\sqrt{\left(x-3\right)\left(x+1\right)}-3\right)< 0\)
\(\Leftrightarrow\left(x-3\right)\left(x+1\right)< 9\Leftrightarrow x^2-2x-12< 0\)
\(\Rightarrow1-\sqrt{13}< x\le-1\)
Vậy nghiệm của BPT là: \(\left[{}\begin{matrix}3< x< 1+\sqrt{5}\\1-\sqrt{13}< x\le-1\end{matrix}\right.\)
giải bpt :
\(\frac{\sqrt{2\left(x^2+7x+3\right)}-\sqrt{x^2+x-6}-3\sqrt{x+1}}{1-2\sqrt{x^2-x+1}}\ge0\)
ĐKXĐ: \(x\ge2\)
Khi đó ta có \(x^2-x+1\ge3\Rightarrow1-2\sqrt{x^2-x+1}< 0\)
Do đó BPT tương đương:
\(\sqrt{2\left(x^2+7x+3\right)}-\sqrt{x^2+x-6}-3\sqrt{x+1}\le0\)
\(\Leftrightarrow\sqrt{2x^2+14x+6}\le\sqrt{x^2+x-6}+3\sqrt{x+1}\)
\(\Leftrightarrow2x^2+14x+6\le x^2+10x+3+6\sqrt{\left(x+1\right)\left(x^2+x-6\right)}\)
\(\Leftrightarrow x^2+4x+3\le6\sqrt{\left(x+1\right)\left(x+3\right)\left(x-2\right)}\)
\(\Leftrightarrow\left(x+1\right)\left(x+3\right)\le6\sqrt{\left(x+1\right)\left(x+3\right)\left(x-2\right)}\)
\(\Leftrightarrow\sqrt{\left(x+1\right)\left(x+3\right)}\le6\sqrt{x-2}\)
\(\Leftrightarrow\left(x+1\right)\left(x+3\right)\le36\left(x-2\right)\)
\(\Leftrightarrow x^2-32x+75\le0\)
\(\Rightarrow16-\sqrt{181}\le x\le16+\sqrt{181}\)
giải BPT : a) \(\sqrt{11+x}+\sqrt{1-x}< 2-\frac{x^2}{4}\)
b) \(x+\frac{2x}{\sqrt{x^2-4}}>3\sqrt{5}\)
c) \(\left(x+2\right)\sqrt{4-x^2}=< -2x-8\)
a/ ĐKXĐ: ....
\(VT=\sqrt{11+x}+\sqrt{1-x}\ge\sqrt{11+x+1-x}=\sqrt{12}\)
\(VP=2-\frac{x^2}{4}\le2< \sqrt{12}\)
\(\Rightarrow VP< VT\Rightarrow\) BPT vô nghiệm
b/
ĐKXĐ: ...
- Với \(x\le0\Rightarrow VT\le0< VP\Rightarrow\) BPT vô nghiệm
- Với \(x>0\) \(\Rightarrow x>2\) hai vế đều dương, bình phương:
\(x^2+\frac{4x^2}{x^2-4}+\frac{4x^2}{\sqrt{x^2-4}}>45\)
\(\Leftrightarrow\frac{x^4}{x^2-4}+\frac{4x^2}{\sqrt{x^2-4}}-45>0\)
Đặt \(\frac{x^2}{\sqrt{x^2-4}}=t>0\)
\(\Rightarrow t^2+4t-45>0\Rightarrow\left[{}\begin{matrix}t< -9\left(l\right)\\t>5\end{matrix}\right.\)
\(\Rightarrow\frac{x^2}{\sqrt{x^2-4}}>5\Leftrightarrow x^4>25\left(x^2-4\right)\)
\(\Leftrightarrow x^4-25x^2+100>0\Rightarrow\left[{}\begin{matrix}x^2< 5\\x^2>20\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2< x< \sqrt{5}\\x>2\sqrt{5}\end{matrix}\right.\)
c/
ĐKXĐ: \(-2\le x\le2\)
Do \(-2\le x\le2\Rightarrow x+2\ge0\Rightarrow VT\ge0\) \(\forall x\)
Mà \(VP=-2x-8=-2\left(x+2\right)-4\le-4< 0\)
\(\Rightarrow VP< VT\)
Vậy BPT đã cho vô nghiệm
bài 1giải bpt
a) frac{x+2}{3}-x+1x+3
b) frac{3x+5}{2}-1lefrac{x+2}{3}+x
c) frac{left(x-2right)sqrt{x-1}}{sqrt{x-1}} 2
bài 2 giải hệ bpt
a) left{{}begin{matrix}2-x02x+1x-2end{matrix}right.
b) left{{}begin{matrix}frac{2x-1}{3} -x+1frac{4-3x}{2} 3-xend{matrix}right.
c) left{{}begin{matrix}-2x+frac{3}{5}frac{3left(2x-7right)}{3}x-frac{1}{2} frac{5left(3x-1right)}{2}end{matrix}right.
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Đọc tiếp
bài 1giải bpt
a) \(\frac{x+2}{3}-x+1>x+3\)
b) \(\frac{3x+5}{2}-1\le\frac{x+2}{3}+x\)
c) \(\frac{\left(x-2\right)\sqrt{x-1}}{\sqrt{x-1}}< 2\)
bài 2 \ giải hệ bpt
a) \(\left\{{}\begin{matrix}2-x>0\\2x+1>x-2\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}\frac{2x-1}{3}< -x+1\\\frac{4-3x}{2}< 3-x\end{matrix}\right.\)
c) \(\left\{{}\begin{matrix}-2x+\frac{3}{5}>\frac{3\left(2x-7\right)}{3}\\x-\frac{1}{2}< \frac{5\left(3x-1\right)}{2}\end{matrix}\right.\)
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