Question

Sa se arate ca: $\sqrt{7+\sqrt{3} }+\sqrt{13+\sqrt{8} } +\sqrt{21+\sqrt{15} } \ \textless \ 12$

Answer 1

$\sqrt{7 + \sqrt{3} } + \sqrt{13 + \sqrt{8} } + \sqrt{21 + \sqrt{15} } < 12 \\ \\ 11,92078 < 12 \: \: (A)$