Chứng minh rằng : \fn_cm \frac{2\sqrt{3+\sqrt{5-\sqrt{13+\sqrt{48}}}}}{\sqrt{6}+\sqrt{2}} là 1 số nguyên
\fn_cm \sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}
\fn_cm \left ( \sqrt{3}-1 \right ).\sqrt{6+2\sqrt{2}.\sqrt{3-\sqrt{}\sqrt{2}+\sqrt{12}+\sqrt{18-\sqrt{128}}}}