Derivatives of Logarithms of Functions
\\ \t $\dfrac{d}{dx}\ln x = \dfrac{1}{x}$ \gap[20] \t
\\ \t $\dfrac{d}{dx}\log_b x = \dfrac{1}{x \ln b} \quad$ \t
#[Applying the chain rule gives][Aplicar la regla de la cadena da]#
\\ \t $\dfrac{d}{dx}\ln \color{#93344}{u} = \dfrac{1}{\color{#93344}{u}}\dfrac{d\color{#93344}{u}}{dx}$ \gap[20] \t
\\ \t $\dfrac{d}{dx}\log_b \color{#93344}{u} = \dfrac{1}{\color{#93344}{u} \ln b}\dfrac{d\color{#93344}{u}}{dx} \quad$ \t
#[Examples][Ejemplos]#
\\ $\dfrac{d}{dx}\ln (x^2+x) = \dfrac{1}{x^2+x}\dfrac{d}{dx}[x^2+x]$ \t ${}= \dfrac{2x+1}{x^2+2}$
\\ $\dfrac{d}{dx}\log_3 (x^2+x) = \dfrac{1}{(x^2+x)\ln 3}\dfrac{d}{dx}[x^2+x]$ \t ${}= \dfrac{2x+1}{(x^2+2)\ln 3}$