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langdu922


1 . [TEX]Cho A = \frac{1}{\sqrt{1}} + \frac{1}{\sqrt{2}} + \frac{1}{\sqrt{3}} + ... + \frac{1}{\sqrt{99}}[/TEX]
[TEX]CMR A > 18[/TEX]
2. CMR :
[TEX]\frac{2 - \sqrt{2 + \sqrt{2 + \sqrt{2 + \sqrt{2}}}}}{2 - \sqrt{2 + \sqrt{2 + \sqrt{2}}}} < \frac{1}{3}[/TEX]
[TEX]CMR A > 18[/TEX]
2. CMR :
[TEX]\frac{2 - \sqrt{2 + \sqrt{2 + \sqrt{2 + \sqrt{2}}}}}{2 - \sqrt{2 + \sqrt{2 + \sqrt{2}}}} < \frac{1}{3}[/TEX]