Question

How do I have to interpret the 2 in the next log?

Answer 1

It means you have to multiply log(x) by itself.

$\frac{d}{dx}(log(x))^2 \\ \frac{d}{d(log(x))}(log(x))^{2} \times \frac{d}{dx}(log(x)) \\ 2log(x) \times \frac{1}{ln(10)x} \\ \frac{2log(x)}{ln(10)x}$