Code: Select all
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[mark=none]
\addplot[red,samples=200,domain=-2*pi:2*pi] { (sin(deg(x)))^2 } ;
\addplot[green,samples=200,domain=-2*pi:2*pi] { sin(deg(x))*(abs(sin(deg(x)))) } ;
\end{axis}
\end{tikzpicture}
\end{document}