帮助在 LaTeX 中用点和弦绘制圆弧？

Question

有人可以帮我用 LaTeX 画这个吗？

Answer 1

您可以通过贝塞尔曲线上的位置获取坐标。

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}
% taking coordinates via positions along the curve
\draw (0,0) ..controls +(-60:2) and +(-135:2) .. (6,0)
coordinate[pos=0] (x1) 
coordinate[pos=.1] (x2)
coordinate[pos=.2] (x3)
coordinate[pos=.4] (xi-1)
coordinate[pos=.55] (xi)
coordinate[pos=.85] (xn-1)
coordinate[pos=1] (xn)
;

\draw[dashed,red] (xi-1)--(xn);
\draw[blue] (x1)--(xi);

\fill (x1)   circle(1.5pt) node[left]{$x=x_1$};
\fill (x2)   circle(1.5pt) node[left]{$x_2$};
\fill (x3)   circle(1.5pt) node[below]{$x_3$};
\fill (xi-1) circle(1.5pt) node[below]{$x_{i-1}$};
\fill (xi)   circle(1.5pt) node[below]{$x_i$};
\fill (xn-1) circle(1.5pt) node[below right]{$x_{n-1}$};
\fill (xn)   circle(1.5pt) node[right]{$x_n=y$};
\end{tikzpicture}
\end{document}