\(A=\sqrt{x+\sqrt{2x-1}}-\sqrt{x-\sqrt{2x-1}}\)
\(A\sqrt{2}=\sqrt{2x+2\sqrt{2x-1}}-\sqrt{2x-2\sqrt{2x-1}}\)
\(A\sqrt{2}=\sqrt{2x-1+2\sqrt{2x-1}+1}-\sqrt{2x-1-2\sqrt{2x-1}+1}\)
\(A\sqrt{2}=\sqrt{\left(\sqrt{2x-1}+1\right)^2}-\sqrt{\left(\sqrt{2x-1}-1\right)^2}\)
\(A\sqrt{2}=\sqrt{2x-1}+1-\sqrt{2x-1}+1\)
\(A\sqrt{2}=2\Leftrightarrow A=\dfrac{2}{\sqrt{2}}=\sqrt{2}\)
Sai thì nhớ báo mình nha.