Tính \(C=\frac{2}{\sqrt{4}+3.\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}\)
Bài 1: Tính giá trị của biểu thức:
1)\(H=\sqrt[3]{3+\sqrt{9+\frac{125}{7}}}-\sqrt[3]{-3+\sqrt{9+\frac{125}{7}}}\)
2)\(P=\frac{2}{\sqrt{4-3\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}}\)
Bài 2: Tính giá trị biểu thức: \(Q=\sqrt[10]{\frac{19+6\sqrt{10}}{2}}.\sqrt[5]{3\sqrt{2}-2\sqrt{5}}\)
\(K=\frac{\sqrt{\sqrt[4]{8}+\sqrt{\sqrt{2}-1}}-\sqrt{\sqrt[4]{8}-\sqrt{\sqrt{2}-1}}}{\sqrt{\sqrt[4]{8}-\sqrt{\sqrt{2}+1}}}\)
Tính: \(\frac{2}{\sqrt{4-3\sqrt[4]{5}}+2\sqrt{5}-\sqrt[4]{125}}\)
Rút gọn biểu thức 1. \(D=\sqrt{5}-\sqrt{13-4\sqrt{9-4\sqrt{5}}}\)
2. \(B=2\sqrt{125}+\sqrt{\left(1-\sqrt{5}\right)^2}-\frac{4}{\sqrt{5}+1}\)
3.\(C=\frac{2}{\sqrt{3}+1}-\frac{1}{\sqrt{3}-2}+\frac{12}{\sqrt{3}+3}\)
\(D=\sqrt{5}-\sqrt{13-4\sqrt{\left(\sqrt{5}-2\right)^2}}=\sqrt{5}-\sqrt{13-4\left(\sqrt{5}-2\right)}\)
\(=\sqrt{5}-\sqrt{21-4\sqrt{5}}=\sqrt{5}-\sqrt{\left(2\sqrt{5}-1\right)^2}\)
\(=\sqrt{5}-2\sqrt{5}+1=1-\sqrt{5}\)
\(B=10\sqrt{5}+\left|1-\sqrt{5}\right|-\frac{4\left(\sqrt{5}-1\right)}{\left(\sqrt{5}+1\right)\left(\sqrt{5}-1\right)}\)
\(=10\sqrt{5}+\sqrt{5}-1-\sqrt{5}+1=10\sqrt{5}\)
\(C=\frac{2\left(\sqrt{3}-1\right)}{\left(\sqrt{3}+1\right)\left(\sqrt{3}-1\right)}+\frac{2+\sqrt{3}}{\left(2+\sqrt{3}\right)\left(2-\sqrt{3}\right)}+\frac{12\left(3-\sqrt{3}\right)}{\left(3+\sqrt{3}\right)\left(3-\sqrt{3}\right)}\)
\(=\sqrt{3}-1+2+\sqrt{3}+2\left(3-\sqrt{3}\right)=7\)
Tính giá trị biểu thức : \(\frac{2}{\sqrt{4-3\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}}\)
Đặt \(\sqrt[4]{5}=x\) thì \(x^4=5\). Ta có :
A = \(\frac{2}{\sqrt{4-3x+2x^2-x^3}}\)= \(\frac{2\left(x+1\right)}{\sqrt{\left(x+1\right)^2\left(4-3x+2x^2-x^3\right)}}\)= \(\frac{2\left(x+1\right)}{\sqrt{-x^5+5x+4}}\)
Ta thấy \(-x^5+5x\) = \(x\left(5-x^4\right)\)= \(0\)
nên A = \(\frac{2\left(x+1\right)}{\sqrt{4}}\)= \(x+1\)=\(\sqrt[4]{5}+1\)
ai giúp mình với tính giá trị biểu thức:\(\frac{2}{\sqrt{4-3\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}}\)
CHỨNG MINH RẰNG: \(\frac{2}{\sqrt{4-3\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}}=1+\sqrt[4]{5}\)
\(B=\frac{2}{\sqrt{4-3\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}}\)
Tính \(\frac{2\sqrt{3}-4}{\sqrt{3}-1}+\frac{2\sqrt{2}-1}{\sqrt{2}-1}-\frac{1+\sqrt{6}}{\sqrt{2}+3}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+2\sqrt{12}}}}}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\left(2+\sqrt{3}\right)}}}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{28-10\sqrt{3}}}}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{28-2\sqrt{75}}}}\)
\(C=\sqrt{4+\sqrt{5\sqrt{3}+5\left(5-\sqrt{3}\right)}}\)
\(C=\sqrt{4+5}\)
\(C=3\)
Bài 1: Tính
1, \(A=\left(1-\frac{5+\sqrt{5}}{1+\sqrt{5}}\right).\left(\frac{5-\sqrt{5}}{1-\sqrt{5}}-1\right)\)
2, \(B=\left(\frac{3\sqrt{125}}{15}-\frac{10-4\sqrt{6}}{\sqrt{5}-2}\right).\frac{1}{\sqrt{5}}\)
3, \(C=\left(\frac{\sqrt{1000}}{100}-\frac{5\sqrt{2}-2\sqrt{5}}{2\sqrt{5}-8}\right).\frac{\sqrt{10}}{10}\)
4, \(D=\frac{1}{\sqrt{49+20\sqrt{6}}}-\frac{1}{\sqrt{49-20\sqrt{6}}}+\frac{1}{\sqrt{7-4\sqrt{3}}}\)
5, \(E=\frac{1}{\sqrt{4-2\sqrt{3}}}-\frac{1}{\sqrt{7-\sqrt{48}}}+\frac{3}{\sqrt{14-6\sqrt{5}}}\)
6, \(F=\frac{1}{\sqrt{2}-\sqrt{3}}\sqrt{\frac{3\sqrt{2}-2\sqrt{3}}{3\sqrt{2}+2\sqrt{3}}}\)
7, \(G=\frac{\sqrt{15-10\sqrt{2}}+\sqrt{13+4\sqrt{10}-\sqrt{11-2\sqrt{10}}}}{2\sqrt{3+2\sqrt{2}}+\sqrt{9-4\sqrt{2}+\sqrt{12+8\sqrt{2}}}}\)