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2#
发表于 2020-4-10 12:10
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對$\sqrt{161-\sqrt{24769}}$開方就證到架喇
個核心價值就係$\displaystyle\sqrt{a-\sqrt{b}}=\frac{\sqrt{a+\sqrt{a^2-b}}-\sqrt{a-\sqrt{a^2-b}}}{\sqrt{2}}$
$\displaystyle\sqrt{161-\sqrt{24769}}=\frac{\sqrt{161+24\sqrt{2}}-\sqrt{161-24\sqrt{2}}}{\sqrt{2}}$ |
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