Answer
$ y=\displaystyle \frac{\log(x-2)}{\log 3}$
Work Step by Step
Assuming that the graphing utility does not have defined logarithms with bases other than 10 or e, we apply the Change of base property: $\displaystyle \quad \log_{b}M=\frac{\log_{a}M}{\log_{a}b}$
Change to base 10 (common logarithm)
$ y=\displaystyle \log_{3}(x-2)=\frac{\log(x-2)}{\log 3}$
See graph.