# How do you find the derivative of y=ln(2x)?

This is the composite of $\ln x$ and $2 x$, so we use the Chain Rule together with the facts that $\left(2 x\right) ' = 2$ and that $\left(\ln x\right) ' = \frac{1}{x}$:
$\left(\ln \left(2 x\right)\right) ' = \frac{1}{2 x} \setminus \times \left(2 x\right) ' = \frac{2}{2 x} = \frac{1}{x}$.