Chứng minh:
\(\frac{7}{{16}}\ln (3 + 2\sqrt 2 ) - 4\ln (\sqrt 2 + 1) - \frac{{25}}{8}\ln (\sqrt 2 - 1) = 0\)
Ta có:
\(\begin{array}{*{20}{l}}
{\frac{7}{{16}}\ln (3 + 2\sqrt 2 ) - 4\ln (\sqrt 2 + 1) - \frac{{25}}{8}\ln (\sqrt 2 - 1)}\\
{ = \frac{7}{{16}}\ln {{(\sqrt 2 + 1)}^2} - 4\ln (\sqrt 2 + 1) - \frac{{25}}{8}\ln \frac{1}{{\sqrt 2 + 1}}}\\
{ = \frac{7}{8}\ln (\sqrt 2 + 1) - 4\ln (\sqrt 2 + 1) - \frac{{25}}{8}\ln \frac{1}{{\sqrt 2 + 1}} = 0}
\end{array}\)
-- Mod Toán 12
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