latex中怎么写数学公式（latex斜面物体受力平衡动态分析）

\documentclass[tikz,border=0.5cm]{standalone} \usepackage[UTF8]{ctex} \usetikzlibrary{math,angles,calc,quotes} \begin{document} \foreach \a in {30,31,...,60}{ \begin{tikzpicture} \begin{scope} %\def\a{40} \tikzmath{coordinate \p,\f; \p1=(0,0);\p2=(\a:6);\p3=(\px2,0); \f1=(-90-\a:1);\f2=(0,\fy1);\f3=(\fx1,0); \f4=(-\fx1,0);\f5=(0,-\fy1);} \coordinate(o)at(\p1); \coordinate(a)at(\p2); \coordinate(b)at(\p3); \draw(o)--(a)--(b)--cycle; \begin{scope}%%%%下方为画布旋转 [transform canvas={rotate=\a},xshift=3cm,yshift=1ex] \node[draw,minimum height=2ex,minimum width=3ex]at(0,0){}; %%%画木块 \fill(0,0)circle(1pt); \draw[-stealth,dashed](-2,0)--(3,0)node[above]{$x$}; \draw[-stealth,dashed](0,-1.5)--(0,2)node[left]{$y$}; \coordinate(wo)at(0,0);\coordinate(g)at(\f1); \coordinate(gy)at(\f2);\coordinate(gx)at(\f3); \coordinate(f)at(\f4);\coordinate(n)at(\f5); \draw[-stealth](wo)--(g)node[below,rotate=-\a]{ $mg$}; \draw[-stealth](wo)--(f)node[above]{ $f$}; \draw[-stealth](wo)--(n)node[left]{\small $F_N$}; \draw[-stealth,gray](wo)--(gy); \draw[-stealth,gray](wo)--(gx); \pic[ draw, angle eccentricity=2, angle radius=2ex] {angle=g--wo--gy};%%%%%%%%%%%%画角度 \end{scope} \pic["$\a^\circ$", draw, angle eccentricity=2, angle radius=3ex] {angle=b--o--a};%%%画角度并标记 \end{scope} \begin{scope} \tikzstyle{box1} = [rectangle, minimum width=9.4cm,minimum height=8cm]%%%定义盒子1 \tikzstyle{box2} = [rectangle, minimum width =2cm,minimum height=1cm,rounded corners, inner color=black,inner sep=1cm,outer color =gray, text=white] %%定义盒子2 \node[box1](a)at(2.8,3){}; \node [box2, anchor=north west, at=(a.south west),align=left] (port1) { %%两个盒子拼接align文本左边对齐 \heiti \Large 1. 摩擦力$f$随着倾角增大而增大\\[1ex] \heiti \Large 2. 支持力$F_N$随着倾角增大而减小 }; \end{scope} \end{tikzpicture}} \end{document}