Differentiate ln$(100|x|)$ I asked to find $\frac{\text{dy}}{\text{dx}}$ for $y = \ln(100|x|)$.
\begin{eqnarray}
\frac{\text{d}\,\text{ln}(100|x|)}{\text{dx}}  &amp;=&amp; \frac{\text{d ln(100|x|)}}{\text{d 100|x|}} \cdot \frac{\text{d (100|x|)}}{\text{dx}}\\
&amp;=&amp;\frac{1}{\text{100|x|}}\cdot \frac{\text{d (100|x|)}}{\text{dx}}
\end{eqnarray}

I'm not sure how to calculate the derivative of 100$|x|$. Any hints would be appreciated.
Notice that

$$\ln(100|x|)=\ln(100)+\ln|x|$$

Thus, derivative is simply given as

$$\frac d{dx}\ln(100|x|)=\frac1x$$
The derivative of ln functions is simply ln(f(x))=f'(x)/f(x)