\documentclass[12pt]{article}
\usepackage{pgfplots}
\usepgfplotslibrary{fillbetween}
\usetikzlibrary{patterns}
\usepackage{hyperref}
\usepackage{graphicx}
\usepackage[labelsep=period,hang]{caption}
\usepackage{setspace}
\usepackage{amsmath,amsfonts,amssymb}
\doublespacing
\usepackage{marvosym}
\usepackage{MnSymbol,wasysym,boldline}
\usepackage{roundbox,graphicx,framed}
\usepackage{fontspec}
\usepackage{fancybox}
\usepackage{draftwatermark}
\usepackage{color,xcolor}
%\usepackage{pgf,tikz,pgfplots}
%\pgfplotsset{compat=1.15}
\usepackage{mathrsfs}
%\usetikzlibrary{arrows}
%\pagestyle{empty}
\usepackage[top=20mm, bottom=20mm, left=20mm, right=20mm,nohead]{geometry}
%\usepackage{tikz}
%\usetikzlibrary{shapes,snakes}
\usepackage{array}
\usepackage{arydshln}
\usepackage{bigdelim}
\usepackage{tikz,pgf,pgfplots}
\usetikzlibrary{arrows.meta}
\usepackage{multicol}
\newcommand{\tikzmark}[2]{\tikz[remember picture,baseline=(#1.base)] \node (#1) {#2};}
\usepackage{datetime}
\usepackage{enumerate}
\usepackage{xepersian}
\let\oldSetWatermarkText\SetWatermarkText
\renewcommand{\SetWatermarkText}[1]{\oldSetWatermarkText{\textbf{\textcolor{teal!20}{#1}}}}
\settextfont{XB Zar}
%\settextfont{ZB Zar}
%\defpersianfont\CS{Lotus}
%\settextfont{Lotus}
%\setdigitfont{IRLotusICEE}
\SetWatermarkLightness{0.90}
\SetWatermarkAngle{-55}
\SetWatermarkScale{0.55}
\SetWatermarkText{{\lr{S. Mostafa Zebarjad}}}
\title{
	{\Huge ریاضی عمومی یک }\\ {\LARGE مساحت ناحیه‌ی محصور}}
\author{
	{\Large سید مصطفی زبرجد}}
%\date{}
\normalsize
\begin{document}
	\maketitle
\begin{tikzpicture}
	\begin{axis}[
		xlabel=$x$,
		ylabel=$y$,
		domain=-2:1,
		samples=100,
		axis lines=center
		]
		
		% Plot y=sqrt(x)
		\addplot[name path=f,blue!100] {x^2};
		
		% Plot x=y^3
		\addplot[name path=g,red!100] {x^0.4};
	
		% Plot y=2-x
	\addplot[name path=h,brown!100] {2-x};
		
	 Fill the area between the curves
		\addplot[pattern=north west lines, pattern color=blue!100] fill between[of=h and f ];
		\addplot[pattern=north west lines, pattern color=black!100] fill between[of=h and g ];
%	\addplot[pattern=north west lines, pattern color=red!100] fill between[of=f and g ];
		
	\end{axis}
\end{tikzpicture}
\newline
	\begin{tikzpicture}
	[line cap=round,line join=round,x=2cm,y=2cm,]
	%	\draw [color=lightgray,dash pattern=on 1pt off 1pt, xstep=2cm,ystep=2cm]
	%	(-2.1,-2.1) grid (4.1,4.1);
	\draw[-latex,color=darkgray,thin] (-2.5,0) -- (3.5,0);
	\foreach \x in {-2,-1,1,2}
	\draw[shift={(\x,0)},color=darkgray,thin] (0pt,1pt) -- (0pt,-1pt)
	node[below] {\footnotesize $\x$};
	\draw[-latex,color=darkgray] (0,-1.2) -- (0,4.5);
	\foreach \y in {1,2,4}
	\draw[shift={(0,\y)},color=darkgray,thin] (1pt,0pt) -- (-1pt,0pt)
	node[left] {\footnotesize $\y$};
	\draw[color=black] (0pt,-8pt) node[left] {\footnotesize $0$};
	%some function
	\draw[color=blue,ultra thick,samples=1000,domain=-2.1:1.2,]
	plot(\x,{\x*\x}) node [ above right]{\large$y=x^2$};
	\draw[color=red,ultra thick,samples=1000,domain=-2.2:2.5]
	plot(\x,{2-\x})node [ above right]{\large${x+y=2}$};
	\draw[color=black,ultra thick,samples=1000,domain=-1.1:2.1,]
	plot(\x,{\x^(1/3)}) node [ above right]{\large$x=y^3$};
	\draw[dashed, brown, thick](1,0)--(1,1);
	\draw[dashed, brown, thick](-2,0)--(-2,4);
	\draw[dashed, brown,ultra thick](0,0)--(0,2);
	\node[red ] at (-1/2,3/2) {\mbox{{\Large $S_1$}}};
	\node[red ] at (0.4,1.2) {\mbox{{\Large $S_2$}}}
	;
\end{tikzpicture}
\end{document}