\documentclass{article}
\usepackage{pst-plot,pstcol}
\begin{document}
%\noindent Sin(x)
\begin{pspicture}(-.5,-.5)(9,2.5)
\psset{xunit=1cm,yunit=1cm}
\psaxes[axesstyle=axes,tickstyle=bottom](0,0)(0,2.5)(9,0)
\psset{plotpoints=50}
\rput(-.2,2.5){y}
\rput(9,-.2){x}
\psplot[plotstyle=line]{.5}{9}{x 90 mul sin 1 add}
\psplot[linestyle=dashed]{0}{9}{1}
\psplot[linestyle=dashed]{0}{9}{2}
\psline[linestyle=dashed](1,0)(1,2)
\psline[linestyle=dashed](9,0)(9,2)
\end{pspicture}

\vspace*{1cm}
%\noindent Sin(x)
\begin{pspicture}(-5,-.5)(5,2.5)
\psset{xunit=1cm,yunit=1cm}
%\psaxes[axesstyle=axes](0,0)(-5,0)(5,2.5)
\psset{plotpoints=50}
\rput(-.2,2.5){y}
\rput(5,-.2){x}
\rput(-.2,1){$1/2$}
\rput(-.2,2){$1$}
\rput(-1,-.2){-$\pi/6$}
\rput(1,-.2){$\pi/6$}
\psplot[plotstyle=line]{-5}{5}{x 90 mul sin 1 add}
\psplot[linestyle=dashed]{-5}{5}{2}
\psplot[linestyle=solid]{-5}{5}{0}
\psline[linestyle=solid](0,0)(0,2)
\psline[linestyle=dashed](1,0)(1,2)
\end{pspicture}


\vspace{1cm}
%\noindent Unit Circle 
\smallskip
\begin{pspicture}(-1.9,-1.9)(1.9,1.9)
\psset{xunit=2cm,yunit=2cm}
\psset{plotpoints=50}
\rput(-.2,1.5){y}
\rput(1.5,-.2){x}
\rput(-1.3,1.0){$x^2+y^2=1$}
\pscircle(0,0){1}
%\pswedge[fillstyle=vlines,hatchangle=-30](0,0){1}{0}{120}
\pswedge[fillstyle=solid,fillcolor=lightgray](0,0){1}{0}{120}
% draw axes
\psaxes[axesstyle=axes](0,0)(-1.5,-1.5)(1.5,1.5)
\rput(.2,.2){$\theta$}
\psarc[arrows=->](0,0){.3}{0}{120}
\end{pspicture}
\end{document}