Tìm đkxđ \(\sqrt{\frac{2}{x^2}}\)
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dk , x lơn hơn hoặc = 0 , x khác 4
\(\frac{\sqrt{x}}{\sqrt{x-2}}\times\frac{x-4}{2\sqrt{x}}+\frac{\sqrt{x}}{\sqrt{x+2}}\times\frac{x-4}{2\sqrt{x}}.\)
có \(x-4=\left(\sqrt{x}-2\right)\left(\sqrt{x+2}\right)\)
\(\frac{\sqrt{x}}{\sqrt{x}-2}\times\frac{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}{2\sqrt{x}}+\frac{\sqrt{x}}{\sqrt{x}+2}+\frac{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}{2\sqrt{x}}\)
rút gọn
\(\frac{\left(\sqrt{x}+2\right)}{2}+\frac{\left(\sqrt{x}-2\right)}{2}\)
\(\frac{2\sqrt{x}}{2}\)
1) ĐK: \(x\ge0;x\ne1\)
2) \(E=\frac{\sqrt{x}-2}{x-1}-\frac{\sqrt{x}+2}{x+2\sqrt{x}+1}\)
\(=\frac{\sqrt{x}-2}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}-\frac{\sqrt{x}+2}{\left(\sqrt{x}+1\right)^2}\)
\(=\frac{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)-\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)^2\left(\sqrt{x}-1\right)}\)
\(=\frac{x-\sqrt{x}-2-x-\sqrt{x}+2}{\left(\sqrt{x}+1\right)\left(x-1\right)}=\frac{-2\sqrt{x}}{\left(\sqrt{x}+1\right)\left(x-1\right)}\)
ĐKXĐ: \(\hept{\begin{cases}\sqrt{x}\ne2\\x\ne4\end{cases}\Rightarrow x\ne4}\)
\(P=\left[\frac{\sqrt{x}-2}{\left(\sqrt{x}-2\right).\left(\sqrt{x}+2\right)}+\frac{\sqrt{x}}{\left(\sqrt{x}-2\right).\left(\sqrt{x+2}\right)}\right]:\frac{2.\left(\sqrt{x}+2\right)}{\left(\sqrt{x}-2\right).\left(\sqrt{x+2}\right)}\)
\(P=\frac{2\sqrt{x}-2}{\left(\sqrt{x}-2\right).\left(\sqrt{x+2}\right)}\cdot\frac{\left(\sqrt{x}-2\right).\left(\sqrt{x+2}\right)}{2\sqrt{x}+4}=\frac{2\sqrt{x}-2}{2\sqrt{x}+4}\)
\(P=\frac{x^2-\sqrt{x}}{x+\sqrt{x}+1}-\frac{2x+\sqrt{x}}{\sqrt{x}}+\frac{2'x-1'}{\sqrt{x}-1}\)
Rút gọn ta được:
\(P=\frac{x^1-\sqrt{x}}{x+\sqrt{x}+1}-\frac{1x+\sqrt{x}}{\sqrt{x}}+\frac{1'x-1'}{\sqrt{x}-1}\)
Phần \(\frac{2'x-1'}{\sqrt{x-1}}\) rút gọi được phần 2 thôi
Đề không yêu cầu Giải Phương trình nhé :v
P/s: Có chắc không nhỉ ?
\(ĐKXĐ:x\ge0;x\ne1\)
\(B=\frac{1}{2\sqrt{x}-2}-\frac{1}{2\sqrt{x}+2}+\frac{\sqrt{x}}{1-x}\)
\(B=\frac{1}{2\left(\sqrt{x}-1\right)}-\frac{1}{2\left(\sqrt{x}+1\right)}+\frac{4\sqrt{x}}{2\left(\sqrt{x}+1\right).2\left(\sqrt{x}-1\right)}\)
\(B=\frac{2\sqrt{x}+2-2\sqrt{x}+2+4\sqrt{x}}{4\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(B=\frac{4\sqrt{x}+4}{4\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}=\frac{4\left(\sqrt{x}+1\right)}{4\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}=\frac{1}{\sqrt{x}-1}\)
là \(\frac{1}{2\sqrt{x}-2}-\frac{1}{2\sqrt{x}+2}+\frac{\sqrt{x}}{1-x}nha toi bi nham\)
a, \(P=\left(\frac{x\sqrt{x}}{\sqrt{x}+1}+\frac{x^2}{x\sqrt{x}+1}\right)\left(2-\frac{1}{\sqrt{x}}\right)\)ĐK : \(x\ge0;\sqrt{x}+1>0\)
\(=\left(\frac{x\sqrt{x}\left(x-\sqrt{x}+1\right)+x^2}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\right)\left(\frac{2\sqrt{x}-1}{\sqrt{x}}\right)\)
\(=\left(\frac{x^2\sqrt{x}-x^2+x\sqrt{x}+x^2}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\right)\left(\frac{2\sqrt{x}-1}{\sqrt{x}}\right)\)
\(=\left(\frac{x\sqrt{x}\left(x+1\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\right)\left(\frac{2\sqrt{x}-1}{\sqrt{x}}\right)\)
\(=\frac{x\left(x+1\right)\left(2\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\)
b, \(P=0\Rightarrow\frac{x\left(x+1\right)\left(2\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}=0\Leftrightarrow x\left(x+1\right)\left(2\sqrt{x}-1\right)=0\)
\(\Leftrightarrow x=0;x=-1;x=\frac{1}{4}\)Kết hợp với đk vậy \(x=0;x=\frac{1}{4}\)
\(\sqrt{\frac{2}{x^2}}=\frac{\sqrt{2}}{\left|x\right|}\)
khi đó ĐKXĐ: \(x\ne0\)