Question

Rút gọn: \(\sqrt{13+30\sqrt{2+\sqrt{9+4\sqrt{2}}}}\)

Answer 1

\(\sqrt{13+30\sqrt{2+\sqrt{9+4\sqrt{2}}}}\)

 = \(\sqrt{13+30\sqrt{2+\sqrt{\left(1+2\sqrt{2}\right)^2}}}\)= \(\sqrt{13+30\sqrt{\left(1+\sqrt{2}\right)^2}}\)

Answer 2

= \(\sqrt{43\:+30\sqrt{2}}\) = \(\sqrt{(25+2×5×3\sqrt{2}+18}\) = \(5\:+3\sqrt{2}\)