Solution 1.2:1e
From Förberedande kurs i matematik 2
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- | {{ | + | The quotient rule gives |
- | + | ||
- | {{ | + | {{Displayed math||<math>\begin{align} |
+ | \Bigl(\frac{x}{\ln x}\Bigr)' | ||
+ | &= \frac{(x)'\cdot \ln x - x\cdot (\ln x)'}{(\ln x)^2}\\[5pt] | ||
+ | &= \frac{1\cdot\ln x - x\cdot\dfrac{1}{x}}{(\ln x)^2}\\[5pt] | ||
+ | &= \frac{\ln x-1}{(\ln x)^2}\\[5pt] | ||
+ | &= \frac{1}{\ln x} - \frac{1}{(\ln x)^2}\,\textrm{.} | ||
+ | \end{align}</math>}} |
Current revision
The quotient rule gives
\displaystyle \begin{align}
\Bigl(\frac{x}{\ln x}\Bigr)' &= \frac{(x)'\cdot \ln x - x\cdot (\ln x)'}{(\ln x)^2}\\[5pt] &= \frac{1\cdot\ln x - x\cdot\dfrac{1}{x}}{(\ln x)^2}\\[5pt] &= \frac{\ln x-1}{(\ln x)^2}\\[5pt] &= \frac{1}{\ln x} - \frac{1}{(\ln x)^2}\,\textrm{.} \end{align} |