Tinh: (2+ \(\sqrt{3}\)).(2 - \(\sqrt{3}\))
Những câu hỏi liên quan
\(\frac{2+\sqrt{3}}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\frac{2-\sqrt{3}}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
tinh ho minh voi, thanks
Thuc hien phep tinh:
B=\(\frac{2+\sqrt{3}}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\frac{2-\sqrt{3}}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
Thuc hien phep tinh: B=\(\dfrac{2+\sqrt{3}}{\sqrt{2}+\sqrt{2+\sqrt{2}}}+\dfrac{2-\sqrt{3}}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
\(B=\dfrac{2+\sqrt{3}}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\dfrac{2-\sqrt{3}}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
\(=\sqrt{2}\left(\dfrac{2+\sqrt{3}}{2+\sqrt{3}+1}+\dfrac{2-\sqrt{3}}{2-\sqrt{3}+1}\right)\)
\(=\sqrt{2}\left(\dfrac{2+\sqrt{3}}{3+\sqrt{3}}+\dfrac{2-\sqrt{3}}{3-\sqrt{3}}\right)\)
\(=\sqrt{2}\cdot\dfrac{6-2\sqrt{3}+3\sqrt{3}-3+6+2\sqrt{3}-3\sqrt{3}-3}{6}\)
\(=\dfrac{1}{3\sqrt{2}}\cdot\dfrac{6}{1}=\sqrt{2}\)
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tinh \(\sqrt{3+\sqrt{5+2\sqrt{3}}}+\sqrt{3-\sqrt{5+2\sqrt{3}}}\)
khong tinh = may tinh cam tay hay c/m \(\frac{1+\frac{\sqrt{3}}{2}}{1+\sqrt{1+\frac{\sqrt{3}}{2}}}+\frac{1-\frac{\sqrt{3}}{2}}{1-\sqrt{1-\frac{\sqrt{3}}{2}}}=1\)
Ta có: \(4\left(1+\frac{\sqrt{3}}{2}\right)=3+2\sqrt{3}+1=\left(\sqrt{3}+1\right)^2\Rightarrow1+\frac{\sqrt{3}}{2}=\left(\frac{\sqrt{3}+1}{2}\right)^2\)
Tương tự \(1-\frac{\sqrt{3}}{2}=\left(\frac{\sqrt{3}-1}{2}\right)^2\)
\(VT=\frac{\left(\frac{\sqrt{3}+1}{2}\right)^2}{1+\frac{\sqrt{3}+1}{2}}+\frac{\left(\frac{\sqrt{3}-1}{2}\right)^2}{1-\frac{\sqrt{3}-1}{2}}=\frac{\frac{\left(\sqrt{3}+1\right)^2}{4}}{\frac{3+\sqrt{3}}{2}}+\frac{\frac{\left(\sqrt{3}-1\right)^2}{4}}{\frac{3-\sqrt{3}}{2}}\)\(=\frac{\left(\sqrt{3}+1\right)^2}{2.\sqrt{3}\left(\sqrt{3}+1\right)}+\frac{\left(\sqrt{3}-1\right)^2}{2.\sqrt{3}\left(\sqrt{3}-1\right)}=\frac{\sqrt{3}+1}{2\sqrt{3}}+\frac{\sqrt{3}-1}{2\sqrt{3}}=\frac{\sqrt{3}+1+\sqrt{3}-1}{2\sqrt{3}}=1=VP\)
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Tinh\(\frac{\sqrt[3]{a^4}+\sqrt[3]{a^2b^2}+\sqrt[3]{b^4}}{\sqrt[3]{a^2}+\sqrt[3]{ab}+\sqrt[3]{b^2}}\)
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Tinh \(\sqrt{5}\left(\sqrt{6}+1\right):\frac{\sqrt{2\sqrt{3}+\sqrt{2}}}{\sqrt{2\sqrt{3}-\sqrt{2}}}\)
ừm..........................theo mình kết quả là 5 nha!
Nhớ k
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\(\sqrt{5}\left(\sqrt{6}+1\right):\frac{\sqrt{2\sqrt{3}+\sqrt{2}}}{\sqrt{2\sqrt{3}-\sqrt{2}}}\)
Tinh
cho \(x=\sqrt[3]{3+2\sqrt{2}}+\sqrt[3]{2-2\sqrt{2}};y=\sqrt[3]{17+12\sqrt{2}}+\sqrt[3]{17-12\sqrt{2}}.\)
Tinh \(P=x^3+y^3-3\left(x+y\right)\)
\(\sqrt{6+2\sqrt{2}\sqrt{3-\sqrt{4+2\sqrt{3}}}}\)
tinh
\(\sqrt{6+2\sqrt{2}.\sqrt{3-\sqrt{4+2\sqrt{3}}}}\)
= \(\sqrt{6+2\sqrt{2}.\sqrt{3-\sqrt{3+2\sqrt{3}.1}+1}}\)
=\(\sqrt{6+2\sqrt{2}.\sqrt{3-\sqrt{\left(\sqrt{3}+1\right)^2}}}\)
=\(\sqrt{6+2\sqrt{2}.\sqrt{3-\left|\sqrt{3}+1\right|}}\)
=\(\sqrt{6+2\sqrt{2}.\sqrt{3-\sqrt{3}-1}}\)
=\(\sqrt{6+2\sqrt{2}.\sqrt{2-\sqrt{3}}}\)
=\(\sqrt{6+2.\left(\sqrt{2}.\sqrt{2-\sqrt{3}}\right)}\)
=\(\sqrt{6+2.\left(\sqrt{4-2\sqrt{3}}\right)}\)
=\(\sqrt{6+2.\sqrt{\left(\sqrt{3}-1\right)^2}}\)
=\(\sqrt{6+2.\left|\sqrt{3}-1\right|}\)
=\(\sqrt{6+2\sqrt{3}-2}\)
=\(\sqrt{4+2\sqrt{3}}\)
=\(\sqrt{\left(\sqrt{3}+1\right)^2}\)
=\(\left|\sqrt{3}+1\right|\)
=\(\sqrt{3}+1\)
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