سلام
در رسم چنین توابعی ابتدا باید دامنه تابع را مشخص کنید.
\documentclass[a4paper,12pt]{report}
\usepackage{tikz,xcolor}
\usetikzlibrary{shapes}
\tikzstyle{vertex}=[circle,draw,inner sep=0pt,minimum size=3pt]
\newcommand{\vertex}{\node[vertex]}
\tikzstyle{block}=[rectangle,draw,fill=white,text width=0.9cm,text centered,rounded corners,minimum height=0.2cm]
\begin{document}
\begin{center}
\begin{tikzpicture}[scale=0.1]
\draw[very thin,color=gray,step=1cm] (-50,-98) grid (50,98);
\draw[thin,color=gray,step=5cm] (-50,-98) grid (50,98);
\draw[->,>=stealth,thick] (-60,0) -- (60,0) node[below] {$x$};
\draw[->,>=stealth,thick] (0,-102) -- (0,102) node[left] {$y$};
%
\draw [blue,domain=-21:6,samples=500] plot (\x,{sqrt(\x^3-351*\x+1890)});
\draw [blue,domain=-21:6,samples=500] plot (\x,{-sqrt(\x^3-351*\x+1890)});
%
\draw [blue,domain=15:25.3,samples=500] plot (\x,{sqrt(\x^3-351*\x+1890)});
\draw [blue,domain=15:25.3,samples=500] plot (\x,{-sqrt(\x^3-351*\x+1890)});
%
\vertex [red,fill=red](a) at (-3,54) []{};
\node (b) at (-3,59) [block]{{\tiny (-3,54)}};
\vertex [red,fill=red](a) at (-3,-54) []{};
\node (b) at (-3,-59) [block]{{\tiny (-3,-54)}};
%
\vertex [red,fill=red](a) at (23,77) []{};
\node (b) at (23,82) [block]{{\tiny (23,77)}};
\vertex [red,fill=red](a) at (23,-77) []{};
\node (b) at (23,-82) [block]{{\tiny (23,-77)}};
\end{tikzpicture}
\end{center}
\end{document}
دامنه تابع
خروجی:
ویرایش:
\documentclass[a4paper,12pt]{report}
\usepackage{tikz,xcolor}
\usetikzlibrary{shapes}
\tikzstyle{vertex}=[circle,draw,inner sep=0pt,minimum size=3pt]
\newcommand{\vertex}{\node[vertex]}
\tikzstyle{block}=[rectangle,draw,fill=white,text width=0.9cm,text centered,rounded corners,minimum height=0.2cm]
\begin{document}
\begin{center}
\begin{tikzpicture}[scale=0.1]
\draw[very thin,color=gray,step=1cm] (-50,-98) grid (50,98);
\draw[thin,color=gray,step=5cm] (-50,-98) grid (50,98);
\draw[->,>=stealth,thick] (-60,0) -- (60,0) node[below] {$x$};
\draw[->,>=stealth,thick] (0,-102) -- (0,102) node[left] {$y$};
\foreach \x/\xtext in {-50,-45,...,-5,5,10,...,50}
\draw (\x,-2) node{{\tiny $\xtext$}};
\foreach \y/\ytext in {5,10,...,95}
\draw (-2,\y) node{{\tiny $\ytext$}};
\foreach \y/\ytext in {-95,-90,...,-5}
\draw (-3,\y) node{{\tiny $\ytext$}};
%
\draw [blue,domain=-21:6,samples=500] plot (\x,{sqrt(\x^3-351*\x+1890)});
\draw [blue,domain=-21:6,samples=500] plot (\x,{-sqrt(\x^3-351*\x+1890)});
%
\draw [blue,domain=15:25.3,samples=500] plot (\x,{sqrt(\x^3-351*\x+1890)});
\draw [blue,domain=15:25.3,samples=500] plot (\x,{-sqrt(\x^3-351*\x+1890)});
%
\vertex [red,fill=red](a) at (-3,54) []{};
\node (b) at (-3,59) [block]{{\tiny (-3,54)}};
\vertex [red,fill=red](a) at (-3,-54) []{};
\node (b) at (-3,-59) [block]{{\tiny (-3,-54)}};
%
\vertex [red,fill=red](a) at (23,77) []{};
\node (b) at (23,82) [block]{{\tiny (23,77)}};
\vertex [red,fill=red](a) at (23,-77) []{};
\node (b) at (23,-82) [block]{{\tiny (23,-77)}};
\end{tikzpicture}
\end{center}
\end{document}
خروجی کد فوق رو ببین.
موفق باشید