Đặt \(A=\dfrac{\sqrt{\sqrt{5}+2}-\sqrt{\sqrt{5}-2}}{\sqrt{\sqrt{5}+1}}\)
\(\Rightarrow A^2=\dfrac{\left(\sqrt{5}+2\right)-2\sqrt{5-4}+\left(\sqrt{5}-2\right)}{\sqrt{5}+1}\)
\(=\dfrac{2\sqrt{5}-2}{\sqrt{5}+1}\)
\(=\dfrac{2\left(\sqrt{5}-1\right)\left(\sqrt{5}+1\right)}{5-1}\)
\(=\dfrac{2\left(5-1\right)}{5-1}\)
\(=2\)
\(\Rightarrow A=\sqrt{2}\left(A>0\right)\)
\(D=A-\sqrt{3-2\sqrt{2}}\)
\(=\sqrt{2}-\sqrt{\left(\sqrt{2}-1\right)^2}\)
\(=1\)
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