\documentclass{standalone} \usepackage{pgfplots} \pgfplotsset{compat=newest} \begin{document} \begin{tikzpicture} \begin{axis}[ axis lines=middle, xtick=\empty, ytick=\empty, ylabel=$\log\vec x$, xlabel=$\vec x$, xmin=0, ymin=-1, thick, decoration={name=none}, ] \addplot[no marks,blue!80!black,ultra thick,samples=150,domain=1:150] {ln(x-10)-2}; \draw[orange,dashed,ultra thick] (axis cs:8, 0.2) -- (axis cs:120, 3); \end{axis} \end{tikzpicture} \end{document}