## Calculus 10th Edition

$\ln 5$
When x approaches the value $5$ from the right side, $x\rightarrow 5^{+},$ $x\rightarrow 5,$ $x-4\rightarrow 1$, $\sqrt{x-4}\rightarrow 1$, $\displaystyle \frac{x}{\sqrt{x-4}}\rightarrow\frac{5}{1}=5$, $\displaystyle \ln\left(\frac{x}{\sqrt{x-4}}\right)\rightarrow\ln 5$