Bất phương trình:\({\log _2}^2x - 4038{\log _2}x +...

C

- Hướng dẫn giải

\(\begin{array}{l}
{\log _2}^2x - 4038{\log _2}x + {2019^2} + {x^2} - {2^{2020}}x + {2^{4038}} \le 0\\
 \Leftrightarrow {\left( {{{\log }_2}x - 2019} \right)^2} + {\left( {x - {2^{2019}}} \right)^2} \le 0\\
 \Leftrightarrow \left\{ \begin{array}{l}
{\log _2}x - 2019 = 0\\
x - {2^{2019}} = 0
\end{array} \right. \Leftrightarrow x = {2^{2019}}
\end{array}\)