For $a > 0$, I need to find the derivatives of $F(x) = \int\nolimits_{1}^{x}\frac{dt}{t}$ and of $G(x) = \int_{a}^{ax}\frac{dt}{t}$, $x\in \left ( 0,\infty \right )$ and use them to prove that $G(x) = F(x)$ for all $x > 0$.
I am having a hard time imaging how the final statement is true in the first place... Could someone help me imagine/picture this?