Tikz O 符号图片

Question

可以在 Tikz 中绘制这些线条吗？ 怎么做？

    \documentclass{article}
\begin{document}
\usepackage{tikz}
        \begin{tikzpicture}
    \draw[->]  (0,0) -- (8,0) node[anchor=north] {$n$};
    \draw[->]  (0,0) -- (0,5);
    \end{tikzpicture}.
\end{document}

Answer 1

以下是他可以用 tikz 做的事情，你可以用它来调整自己的功能

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc, positioning,fit,intersections}
\begin{document}
\begin{tikzpicture}
    \draw[->]  (0,0)coordinate(O) -- (8,0) node[anchor=north] {$n$};
    \draw[->]  (0,0) -- (0,5);

\draw[domain=0:8,smooth,variable=\x,blue,name path=c1] plot ({\x},{0.5*\x+2*sin(\x r)+1})node[right]{$f_1(n)$};
\draw[domain=0:8,smooth,variable=\x,red,name path=c2] plot ({\x},{0.2*\x+0.5*sin(\x r)+2})node[right,black]{$f_2(n)$};
\fill[red,name intersections={of=c1 and c2}]
    (intersection-1) circle (2pt)
    (intersection-2) circle (2pt)
        (intersection-3) circle (2pt) ;

\draw[dashed] (intersection-2) -- (intersection-2|-O) node[below]{n};
\end{tikzpicture}

\end{document}