Problem 0010 | Logarithm

উদাহরণ ১০৷ সমাধান করো {x^{{{\log }_{10}}x}} = 100x  [H.S’97]

সমাধান:

{x^{{{\log }_{10}}x}} = 100x\\
\Rightarrow {\log _{10}}x = {\log _x}(100x)\\
\Rightarrow {\log _{10}}x = {\log _x}100 + {\log _x}x\\
\Rightarrow {\log _{10}}x = {\log _x}{\left( {10} \right)^2} + 1\\
\Rightarrow {\log _{10}}x = 2{\log _x}10 + 1\\
\Rightarrow {\log _{10}}x - 1 = \frac{2}{{{{\log }_{10}}x}}\\
\Rightarrow a - 1 = \frac{2}{a}\left[ {a = {{\log }_{10}}x} \right]\\
\Rightarrow {a^2} - a = 2\\
\Rightarrow {a^2} - a - 2 = 0\\
\Rightarrow {a^2} - 2a + a - 2 = 0\\
\Rightarrow \left( {a - 2} \right)\left( {a + 1} \right) = 0\\
\Rightarrow a = 2,or,a = - 1
\end{array}" alt="\begin{array}{l}
{x^{{{\log }_{10}}x}} = 100x\\
\Rightarrow {\log _{10}}x = {\log _x}(100x)\\
\Rightarrow {\log _{10}}x = {\log _x}100 + {\log _x}x\\
\Rightarrow {\log _{10}}x = {\log _x}{\left( {10} \right)^2} + 1\\
\Rightarrow {\log _{10}}x = 2{\log _x}10 + 1\\
\Rightarrow {\log _{10}}x - 1 = \frac{2}{{{{\log }_{10}}x}}\\
\Rightarrow a - 1 = \frac{2}{a}\left[ {a = {{\log }_{10}}x} \right]\\
\Rightarrow {a^2} - a = 2\\
\Rightarrow {a^2} - a - 2 = 0\\
\Rightarrow {a^2} - 2a + a - 2 = 0\\
\Rightarrow \left( {a - 2} \right)\left( {a + 1} \right) = 0\\
\Rightarrow a = 2,or,a = - 1
\end{array}"/>

যখন

\begin{array}{l}<br />{\log _{10}}x = 2\\<br /> \Rightarrow x = {\left( {10} \right)^2} = 100<br />\end{array}

যখন

\begin{array}{l}<br />{\log _{10}}x =  - 1\\<br /> \Rightarrow x = {\left( {10} \right)^{ - 1}} = \frac{1}{{100}}<br />\end{array}