如何绘制此图

Question

我想使用 LaTeX（tikz）绘制下图中的图形。

Answer 1

我碰巧有一张类似的但简化的图表，我将其用于我的笔记中。它不能重现你想要的东西，但它是一个很好的、免费的开始。

我建议衍生物包来写导数，特别是字母d（\mathrm{d}）。

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing} %brace
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}[thick]
  \draw[-latex] (0,-1) -- (0,4) node[right]{$y$};
  \draw[-latex] (-2,0) -- (4,0) node[above]{$x$};
  \draw [teal, xshift=0cm] plot [smooth, tension=0.8] coordinates { (-1,0.5) (1,1)(2.5,2.5) (3,4)} node[right]{$f(x)$};
  
  \draw[dashed] (1,0) coordinate(t0) node[below]{$x_0$} -- ++(0,1);
  \draw[dashed] (0,1) node[left] {$y_0 = f(x_0)$} -- ++(1,0) coordinate(P);
  
  \draw[dashed] (2.5,0) coordinate(t1) node[below right]{$x_1 = x_0 + h$} -- ++(0,1);
  \draw[dashed] (0,2.5) node[left] {$y_1 = f(x_1)$} -- ++(2.5,0) coordinate(Q);
  \draw[red] (0.5,0.5) -- (P) -- (Q) -- (3,3);
  \draw[blue, opacity = 0.8] (P) -- ++(1.5,0) coordinate(R) -- (Q);
  \draw[decorate, decoration={brace, mirror, amplitude=5pt}] (t0) -- (t1) node[midway, below = 0.25cm]{$h$};
  
  \draw ($(R) + (0.2,0)$) -- ++(0.5,0);
  \draw ($(Q) + (0.2,0)$) -- ++(0.5,0);
  \draw[latex-latex] ($(R) + (0.5,0)$) -- ($(Q) + (0.5,0)$) node[midway,right]{$\Delta y$};
\end{tikzpicture}
\end{document}